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Variant interpretation report

SLC26A4 c.919-2A>G, p.?

NM_000441.2:c.919-2A>G NP_000432.1:p.? Canonical splice · intron 7 View identifiers
Classification
Uncertain significance

Variant description:

The SLC26A4 NM_000441.2:c.919-2A>G (NP_000432.1:p.?) splicing variant has not previously been reported in somatic cancers (COSMIC). Based on available guidelines, this variant is considered to be a Variant of Uncertain Significance (VUS). This variant is considered to be Pathogenic by the VCEP (ClinGen Hearing Loss Variant Curation Expert Panel; ClinVar ID 4840).

Five-step scale from benign to pathogenic. This variant is uncertain. Select a step to read what it means.

Uncertain.The recorded classification is uncertain significance.

In plain language

Gene-level background from the recorded interpretation.

About SLC26A4

SLC26A4 encodes a protein related to sulfate transporters and is involved in transporting ions across cell membranes. Loss-of-function changes in this gene cause Pendred syndrome, an autosomal-recessive disorder characterized mainly by syndromic hearing loss and often thyroid abnormalities. SLC26A4 is not established as a cancer-related gene.

LYFE Sciences is an AI system, and it can make mistakes. Criteria may be applied incorrectly, sources may be misread, and a confident-looking classification can still be wrong. Double-check every criterion and its underlying evidence before relying on any call.
01The reasoning

How it was classified

The recorded framework is ClinGen SLC26A4 VCEP v2.0. The criteria and strengths shown below come from the saved assessment; this page does not recalculate the classification.

Recorded applied criteria

The applied criteria and their strengths are shown as assessed under the stated framework.

Pathogenic evidence criteria: 4 Benign evidence criteria: 2
Pathogenic criteria applied · 4
PVS1Very strong
PVS1 · very strong

Met at very strong: exact-variant RT-PCR showed complete exon 8 skipping, causing an 83-nucleotide frameshift and premature termination in SLC26A4.

PM3Moderate
PM3 · moderate

Met at Moderate strength: affected patients had compound-heterozygous p.H723R/c.919-2A>G genotypes, documenting the target allele in trans with the disease allele.

PP1Supporting
PP1 · supporting

Met supporting: the splice-site variant segregates with hearing loss in affected relatives, satisfying the VCEP threshold of one affected relative for recessive disease.

PP5Supporting
PP5 · supporting

Not applicable: this VCEP explicitly prohibits PP5, regardless of pathogenic reports for c.919-2A>G.

Benign criteria applied · 2
BA1Stand alone
BA1 · stand alone

Met: gnomAD v2.1 East Asian AF 0.00506367 exceeds the VCEP autosomal-recessive BA1 threshold of 0.005 (0.5%).

BS1Strong
BS1 · strong

Met strong: gnomAD v2.1 East Asian AF 0.00506367 exceeds the VCEP autosomal-recessive BS1 Strong threshold of 0.003 (0.3%).

Recorded classification: Uncertain significance

VUS: PVS1 (very strong), PM3 (moderate), PP1 and PP5 (supporting) conflict with BA1 (stand-alone benign) and BS1 (strong).

02The sources

Evidence at a glance

Evidence summaries and captured source records, where available. Missing entries should not be interpreted as negative findings.

gnomAD v4.1
gnomAD v2.1
Population frequency
125 / 1,613,754 alleles

gnomAD v4.1: 125 / 1,613,754 alleles. Recorded AF 7.74591e-05. Recorded homozygote count 0.

gnomAD v2.1

This variant is present in gnomAD v2.1 (AF= 0.000364718; MAF= 0.03647%, 103/282410 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.00506367; MAF= 0.50637%, 101/19946 alleles, homozygotes = 0); grpmax FAF= 0.00492851.

gnomAD-Canada

Not available in gnomAD-Canada v1.0.

SpliceAI score
0.998 maximum delta

Recorded SpliceAI maximum delta score: 0.998. Refer to the recorded PP3/BP4 rationale for interpretation.

No listed criterion applied SpliceAI ↗
ClinVar submissions
28 reported laboratory submissions

27 Pathogenic · 1 Affects. ClinVar API review status: reviewed by expert panel.

No screenshot for this evidence
Functional evidence
Not recorded

No standalone functional evidence summary is recorded in evidence_summary.functional.

No listed criterion applied OncoKB ↗
Somatic evidence
No matching record reported

This variant has not previously been reported in somatic cancers (COSMIC).

Context only COSMIC ↗
For specialists

Technical detail

ACMG/AMP criteria under ClinGen SLC26A4 VCEP v2.0, with the data and sources behind each one.

28 criteria with recorded statuses: 6 met · 5 not met · 8 not assessed · 9 not applicable. Open any row for the full reasoning, the rule and the evidence behind it.

Met Not met Not assessed Not applicable

For the requested consequence-of-function criteria only, PVS1 is met at very strong strength; PM4 and BP3 are not applicable because the variant is a canonical splice-site substitution rather than an in-frame indel.

Only the VCEP's own Version 2.0 rules were applied. PS4 and PP4 remain not assessed because their required case-control/statistical or Table 7 phenotype-specificity inputs are unavailable; PP5, BP5, and BP6 are not applicable under explicit VCEP restrictions.

The available literature includes affected-family and affected-cohort observations, but these do not substitute for the VCEP's PS4 case-control requirement or PP4 Table 7 phenotype-specificity assessment.

The governing framework is the ClinGen Hearing Loss Expert Panel Version 2.0 specification for SLC26A4.

Only predictors explicitly named by the governing criterion rule were eligible: REVEL and MaxEntScan; SpliceAI was not substituted for either.

The variant is a canonical -2 splice-site variant, so BP7 is outside scope and PP3 has a VCEP-specific interaction with PVS1 use.

Met · 6

PVS1 Very strongVCEPMet at very strong: exact-variant RT-PCR showed complete exon 8 skipping, causing an 83-nucleotide frameshift and premature termination in SLC26A4. Details ▾Hide ▴
Reasoning

NM_000441.2:c.919-2A>G is a canonical acceptor splice variant at -2 of exon 8 in SLC26A4. The affected transcript is the MANE transcript, and skipping exon 8 removes 83 coding nucleotides, shifts the reading frame, and is predicted to cause premature termination; the affected exon is internal (exon 8 of 21), not the first, last, or penultimate exon. RT-PCR for this exact variant demonstrated complete exon 8 skipping with a frameshift and premature termination. A separate study detected residual normally spliced transcript, but the governing VCEP text provides no named downgrade rule for a leaky canonical splice variant, and no specific downgrade rule is established in the supplied VCEP criteria. SLC26A4 is eligible under the VCEP PVS1 gene gate because loss of function is an established disease mechanism. Therefore PVS1 is met at full strength: very strong.

VCEP rule
Null variant in a gene with established LOF as a disease mechanism; see PVS1_Strong, PVS1_Moderate, PVS1_Supporting for reduced evidence applications.
Evidence considered
  • PVS1 variant assessment: NM_000441.2:c.919-2A>G is a canonical splice acceptor variant at -2; exon 8 of 21 is affected, and exon skipping removes 83 coding nucleotides (83 % 3 = 2), producing a frameshift.
  • PVS1 gene context: the official VCEP/CSPEC framework supports SLC26A4 loss of function as an established disease mechanism and marks the PVS1 gene gate eligible.
  • Yang et al., PMID:15574297: RT-PCR demonstrated that the exact variant causes complete exon 8 skipping, resulting in a frameshift and premature termination.
  • Choi et al., PMID:24007330: in two patients homozygous for the exact variant, RNA analysis detected exon-8-skipped and normally spliced transcripts; normal transcripts were approximately 6% of normal in nasal mucosa and 17% in lymphocytes, documenting leaky splicing but not a VCEP-specified downgrade rule.
Sources
cspec ↗pvs1_gene_contextpvs1_variant_assessmentPMID:15574297 ↗PMID:24007330 ↗
PM3 ModerateVCEPMet at Moderate strength: affected patients had compound-heterozygous p.H723R/c.919-2A>G genotypes, documenting the target allele in trans with the disease allele. Details ▾Hide ▴
Reasoning

PM3 is met at Moderate strength. In an affected cohort of 111 Korean patients with bi-allelic SLC26A4 mutations and bilateral enlarged vestibular aqueduct with hearing loss, the study specifically analyzed patients with compound heterozygous p.H723R/c.919-2A>G genotypes. A compound-heterozygous genotype documents the target allele in trans with the p.H723R disease allele in affected individuals. This satisfies the VCEP example for one PM3 point: detected in trans with a pathogenic variant in a recessive disorder.

VCEP rule
1 point awarded from tables 7a and 7b. Example: Detected in trans with a pathogenic variant (recessive).
Evidence considered
  • Lee et al. 2013, PMID:24007330, cohort description: 111 Korean patients with bi-allelic SLC26A4 mutations, bilateral enlarged vestibular aqueduct, and hearing loss.
  • Lee et al. 2013, PMID:24007330, Results, 'Hearing levels according to SLC26A4 mutation genotype': affected patients with compound heterozygous p.H723R/c.919-2A>G genotypes were analyzed, documenting the target allele in trans with p.H723R.
  • ClinGen Hearing Loss VCEP CSPEC PM3 rule: one point is awarded for detection in trans with a pathogenic variant in a recessive disorder, corresponding to Moderate strength.
Sources
PP1 SupportingVCEPMet supporting: the splice-site variant segregates with hearing loss in affected relatives, satisfying the VCEP threshold of one affected relative for recessive disease. Details ▾Hide ▴
Reasoning

The variant is reported with phenotype-consistent hearing loss in affected relatives in multiple family reports. PMID:10874637 describes the splice-site mutation in an extended inbred Pendred syndrome family, including two affected siblings with the splice-site allele and a second mutation; PMID:11502831 reports affected members of a Pendred syndrome family carrying the variant; and PMID:16711435 reports affected twin sisters with DVAS and hearing loss with hearing-normal parents. This establishes segregation in at least one affected relative, meeting the VCEP supporting threshold, but the available extracted records do not provide a sufficiently auditable pedigree-level count and phase assessment for a higher strength.

VCEP rule
Segregation in one affected relative for recessive and two affected relatives for dominant.
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0 PP1 supporting rule: segregation in one affected relative for recessive disease.
  • Coucke et al. 1999, PMID:10874637, extended inbred Turkish Pendred syndrome family: the 1143-2A>G splice-site mutation was present in affected family members, including two affected siblings who were compound heterozygotes for the splice-site and missense mutations.
  • Yong et al. 2001, PMID:11502831, two Pendred syndrome families: family II included two affected offspring and affected parents, with the reported SLC26A4 splice-site variant identified in affected members.
  • Dai et al. 2006, PMID:16711435, familial DVAS: affected twin sisters and affected siblings had sensorineural hearing loss and enlarged vestibular aqueduct, with the reported SLC26A4 splice-site variant identified by sequencing.
Sources
PP5 SupportingVCEPNot applicable: this VCEP explicitly prohibits PP5, regardless of pathogenic reports for c.919-2A>G. Details ▾Hide ▴
Reasoning

Expert panel ClinGen Hearing Loss Variant Curation Expert Panel classified as Pathogenic.

VCEP rule
This criterion is not for use as recommended by the ClinGen Sequence Variant Interpretation VCEP Review Committee.
Evidence considered
  • The VCEP PP5 entry is marked Not Applicable for this VCEP and instructs: This criterion is not for use as recommended by the ClinGen Sequence Variant Interpretation VCEP Review Committee.
  • ClinVar expert panel classification
Sources
BA1 Stand aloneVCEPMet: gnomAD v2.1 East Asian AF 0.00506367 exceeds the VCEP autosomal-recessive BA1 threshold of 0.005 (0.5%). Details ▾Hide ▴
Reasoning

The Hearing Loss VCEP specifies BA1 for an autosomal-recessive variant at MAF >=0.005 (0.5%). SLC26A4 is governed here as autosomal recessive. In gnomAD v2.1, the highest observed population frequency is East Asian AF 0.005063671914168255 (101/19,946 alleles; 0 homozygotes), which exceeds 0.005. gnomAD v4.1 reports a lower East Asian AF of 0.00263005393839433, but the v2.1 population observation independently reaches the VCEP BA1 threshold. No VCEP rule requires the frequency to be present in every population dataset or requires exclusion of the observed ancestry-specific maximum.

VCEP rule
MAF of ≥0.005 (0.5%) for autosomal recessive; MAF of ≥0.001 (0.1%) for autosomal dominant.
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC v2.0, BA1 criteria entry: MAF >=0.005 (0.5%) for autosomal recessive.
  • gnomAD v2.1 all-comers population record for SLC26A4 NM_000441.2:c.919-2A>G: total AF 0.0003647179632449276 (103/282410 alleles; 0 homozygotes); highest observed population East Asian AF 0.005063671914168255 (101/19946 alleles; 0 homozygotes); grpmax FAF 0.004928510000000054.
  • gnomAD v4.1 all-comers population record for SLC26A4 NM_000441.2:c.919-2A>G: total AF 0.00007745914185185598 (125/1613754 alleles; 0 homozygotes); highest observed population East Asian AF 0.00263005393839433 (118/44866 alleles; 0 homozygotes); grpmax FAF 0.0022441.
Sources
BS1 StrongVCEPMet strong: gnomAD v2.1 East Asian AF 0.00506367 exceeds the VCEP autosomal-recessive BS1 Strong threshold of 0.003 (0.3%). Details ▾Hide ▴
Reasoning

The Hearing Loss VCEP specifies BS1 Strong for an autosomal-recessive variant at MAF ≥0.003 (0.3%), provided there is no conflicting evidence. SLC26A4 is autosomal recessive, and the gnomAD v2.1 East Asian frequency is 0.005063671914168255 (101/19,946 alleles; 0 homozygotes), exceeding 0.003. gnomAD v4.1 reports a lower East Asian AF of 0.00263005393839433, but the v2.1 observation meets the stated threshold. The VCEP text does not require concordance across databases or prohibit use of an ancestry-specific maximum.

VCEP rule
MAF of ≥0.003 (0.3%) for autosomal recessive; MAF of ≥0.0002 (0.02%) for autosomal dominant. Likely benign, provided there is no conflicting evidence.
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC v2.0, BS1 Strong criteria entry: MAF >=0.003 (0.3%) for autosomal recessive; likely benign provided there is no conflicting evidence.
  • gnomAD v2.1 all-comers population record for SLC26A4 NM_000441.2:c.919-2A>G: highest observed population East Asian AF 0.005063671914168255 (101/19946 alleles; 0 homozygotes), above 0.003.
  • gnomAD v4.1 all-comers population record for SLC26A4 NM_000441.2:c.919-2A>G: highest observed population East Asian AF 0.00263005393839433 (118/44866 alleles; 0 homozygotes), below 0.003 but not required by the VCEP rule to be concordant with v2.1.
Sources

Not met · 5 · evaluated, threshold not reached

PS2 VCEPNot met: no proven or assumed de novo occurrence is documented; reported cases show familial transmission in affected relatives. Details ▾Hide ▴
Reasoning

No de novo occurrence is documented. The available family reports describe the splice-site variant in affected siblings or multiple affected relatives, with parental or familial inheritance information, rather than a proven de novo event. Therefore the VCEP PS2 de novo point thresholds are not reached.

VCEP rule
4 points per tables 5a and 5b: Examples: 2 proven de novo occurrences; OR 1 proven + 2 assumed de novo occurrences; OR 4 assumed de novo occurrences. ... 2 points per tables 5a and 5b: Examples: 1 proven de novo occurrence; OR 2 assumed de novo occurrences. ... 1 point per tables 5a and 5b: Examples: 1 proven de novo occurrence (phenotype consistent but not specific to gene); OR 1 assumed de novo occurrence; OR 2 assumed de novo occurrences (phenotype/gene not specific). ... 0.5 points per tables 5a and 5b: Example: 1 assumed de novo occurrence (phenotype/gene not specific).
Evidence considered
  • The reported family studies describe c.919-2A>G/legacy splice-site nomenclatures in affected siblings or affected relatives, not a child with confirmed variant absence in both tested parents.
  • PMID:10874637 reports two affected siblings with non-consanguineous parents who were compound heterozygotes for the splice-site mutation and a missense mutation, which is familial inheritance rather than de novo occurrence.
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0 PS2 requires de novo occurrences to be scored by the specified point examples; no qualifying de novo occurrence is available.
Sources
PM2 VCEPNot met: gnomAD v4.1 total AF 0.0000774591 exceeds the VCEP autosomal-recessive PM2 cutoff of 0.00007 (0.007%). Details ▾Hide ▴
Reasoning

The Hearing Loss VCEP permits PM2 at Supporting strength for an autosomal-recessive variant that is absent or has MAF <=0.00007 (0.007%). The all-comers gnomAD v2.1 total AF is 0.0003647179632449276 and the gnomAD v4.1 total AF is 0.00007745914185185598; both exceed 0.00007. The ancestry-specific frequencies are also higher, including East Asian AF 0.005063671914168255 in v2.1 and 0.00263005393839433 in v4.1. Thus the VCEP PM2 Supporting cutoff is not met.

VCEP rule
Absent/Rare in population databases (absent or ≤0.00007 (0.007%) for autosomal recessive, ≤0.00002 (0.002%) for autosomal dominant).
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC v2.0, PM2 Supporting criteria entry: absent or MAF <=0.00007 (0.007%) for autosomal recessive.
  • gnomAD v2.1 all-comers population record: total AF 0.0003647179632449276 (103/282410 alleles; 0 homozygotes); highest observed East Asian AF 0.005063671914168255.
  • gnomAD v4.1 all-comers population record: total AF 0.00007745914185185598 (125/1613754 alleles; 0 homozygotes); highest observed East Asian AF 0.00263005393839433.
Sources
PM6 VCEPNot met: no affected proband has an unproven but assumed de novo occurrence; available reports describe familial segregation. Details ▾Hide ▴
Reasoning

No assumed de novo occurrence is documented. The available reports provide familial segregation and parental observations rather than an affected proband whose variant status in both parents is untested or otherwise only assumed de novo. The VCEP directs PM6 to the PS2 framework, so no PM6 point threshold is reached.

VCEP rule
See PS2 above
Evidence considered
  • The available family reports document affected relatives and parental/familial transmission, not an affected proband with an untested parental genotype supporting assumed de novo status.
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0 states that PM6 uses the PS2 de novo framework; no assumed de novo occurrence is available for this variant.
Sources
BS2 VCEPNot met: gnomAD v2.1 and v4.1 each report 0 homozygotes, with no qualifying biallelic control observation available. Details ▾Hide ▴
Reasoning

The Hearing Loss VCEP requires observation of the variant biallelic with a known pathogenic variant in controls in a manner inconsistent with disease penetrance. gnomAD v2.1 and gnomAD v4.1 each report zero homozygotes for this variant, and no control observation biallelic with a known pathogenic variant is available in the population evidence. Therefore the specified BS2 observation is not present.

VCEP rule
Observation of variant (biallelic with known pathogenic variant for recessive) in controls inconsistent with disease penetrance. ... However, if biallelic observations in controls are inconsistent with disease penetrance, this may be applicable.
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC v2.0, BS2 criteria entry: observation of the variant biallelic with a known pathogenic variant for a recessive disorder in controls inconsistent with disease penetrance.
  • gnomAD v2.1 all-comers population record: homozygotes = 0; East Asian homozygotes = 0.
  • gnomAD v4.1 all-comers population record: homozygotes = 0; East Asian homozygotes = 0.
Sources
BS4 VCEPNot met: no affected relative lacks the variant and unaffected parents are compatible with expected recessive carrier status, not non-segregation. Details ▾Hide ▴
Reasoning

No qualifying non-segregation is documented. The reports describe affected relatives carrying the variant and unaffected parents in recessive families, which is compatible with carrier status and is not genotype-positive/phenotype-negative evidence for the recessive disease. No affected-family member is documented to lack the variant, and no confidently unaffected individual is documented to carry biallelic disease-causing alleles.

VCEP rule
Non-segregation with disease.
Evidence considered
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0 BS4 distinguishes phenotype-positive/genotype-negative and genotype-positive/phenotype-negative non-segregation and cautions that phenotype consistency and true unaffected status must be established.
  • The reported hearing-normal parents in the recessive family report are compatible with heterozygous carrier status and do not constitute genotype-positive/phenotype-negative evidence for recessive hearing loss.
  • No reported family member with a qualifying genotype is documented to have a reliably phenotype-negative diagnostic audiogram, and no affected relative is documented to be genotype-negative.
Sources

Not assessed · 8 · no assessment recorded

PS1 VCEPNot assessed: no different pathogenic substitution at c.919-2 with a comparable splice-impact prediction is available for this canonical splice variant. Details ▾Hide ▴
Reasoning

The VCEP permits PS1 for a splice variant at the same nucleotide as a previously reported pathogenic variant when the impact prediction is similar, with assessment of possible direct DNA-level effects. The available evidence confirms that NM_000441.2:c.919-2A>G is a canonical splice variant and is pathogenic, but it does not identify a different pathogenic nucleotide substitution at c.919-2 or provide a comparator impact prediction. Therefore the VCEP splice-specific PS1 route cannot be evaluated.

VCEP rule
Same amino acid change as an established pathogenic variant; OR splice variants at same nucleotide and with similar impact prediction as previously reported pathogenic variant. * Established variant must meet criteria for pathogenicity by the HL specifications * Can also use PS1 for splice variants located in the splice consensus sequence, at the same nucleotide position as a previously reported pathogenic variant * Example: c.105+1G>C is known to be pathogenic, can use PS1 for c.105+1G>T * No additional hearing loss specifications for missense variants. Follow recommendations as outlined in Richard 2015 and/or the Sequence Variant Interpretation working group within ClinGen. * Caveat (from ACMG/AMP guidelines): Assess the possibility that the variant may act directly through the DNA change (e.g. through splicing disruption as assessed by at least computational analysis) instead of through the amino acid change)
Evidence considered
  • VCEP CSPEC PS1 rule: the splice-specific route requires a previously reported pathogenic variant at the same nucleotide and a similar impact prediction.
  • Case normalization identifies NM_000441.2:c.919-2A>G as a canonical splice variant with protein consequence NP_000432.1:p.?.
  • No qualifying alternate same-nucleotide pathogenic comparator was identified in the available case evidence.
Still missing
  • A previously reported pathogenic SLC26A4 variant with a different nucleotide change at c.919-2 and a comparable impact prediction is not available.
Sources
PS3 VCEPNot assessed: RNA studies show exon 8 skipping and only 6–17% normal transcript, but the VCEP specifies SLC26A4 radio-isotope or fluorescence assays for PS3. Details ▾Hide ▴
Reasoning

The available studies provide variant-specific RNA evidence for a deleterious splice effect, but the VCEP's SLC26A4 PS3 path is restricted to radio-isotope or fluorescence assays. PMID:15574297 reports complete exon 8 skipping, a frameshift, and premature termination by RT-PCR, and PMID:24007330 reports reduced normal transcript (approximately 6% of normal in nasal mucosa and 17% in lymphocytes) with both normal and exon-8-skipped transcripts. However, no qualifying radio-isotope result showing statistically significant decreased iodide efflux or fluorescence result showing a statistically significant ΔFmax% difference from wild type and no significant difference from empty vector is available. The VCEP's separately stated allowance for other functional analyses is framed for other genes/functional analyses, not as an alternative SLC26A4 assay path; therefore PS3 cannot be assigned from these RNA studies under the governing rule.

VCEP rule
SLC26A4: Radio isotope and fluorescence assays → PS3_Supporting * Radio Isotope Assays: PS3_Supporting would be applied when cells transfected with mutant SLC26A4 show a statistically significant decreased efflux of iodide compared to wildtype pendrin. * Fluorescence Assays: PS3_Supporting would be applied when a cell transfected with the mutant SLC26A4 shows a statistically significant difference in fluorescence (ΔFmax %) compared to the wildtype protein, and when the fluorescence is not significantly different from that of an empty vector control.
Evidence considered
  • Yang et al. 2005, PMID:15574297, RT-PCR and sequencing of peripheral-blood lymphocyte cDNA from patients with IVS7-2A>G: the mutant transcript skipped exon 8, joining exons 7 and 9, with a resulting frameshift and premature termination; the study examined 10 prelingual deaf patients from seven unrelated families.
  • Choi et al. 2013, PMID:24007330, RT-PCR, sequencing, and quantitative real-time PCR in two patients homozygous for c.919-2A>G: both exon-8-skipped and normally spliced transcripts were detected, with normal transcript approximately 6% of normal in nasal mucosa and 17% in lymphocytes.
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0, PS3 supporting rule: SLC26A4 radio-isotope and fluorescence assays are the specified functional paths; the available studies are RNA splicing assays rather than either specified assay.
Still missing
  • A VCEP-specified SLC26A4 radio-isotope assay result with statistically significant decreased iodide efflux versus wild-type pendrin is unavailable.
  • A VCEP-specified SLC26A4 fluorescence assay result with ΔFmax% significantly different from wild type and not significantly different from empty vector is unavailable.
Sources
PS4 VCEPNot assessed: the available affected-cohort data report c.919-2A>G in 24% of 111 biallelic cases but provide no matched controls or case-control statistical test. Details ▾Hide ▴
Reasoning

The VCEP's strong PS4 rule requires a Fisher Exact or Chi-Squared analysis showing a statistical increase in cases over controls, or an autosomal-dominant proband-count route. SLC26A4 is specified here as autosomal recessive, so the dominant count routes do not apply. The reviewed literature includes affected cohorts and family reports, including 111 Korean patients with biallelic SLC26A4 variants and c.919-2A>G in 24% of alleles, but no matched control count, case-control table, or reported statistical test for this exact variant was available; therefore an odds ratio, confidence interval, and Fisher/Chi-Squared result cannot be established. The literature_pass PS4 index was also checked: its listed PS4 PMIDs were not in the already-read AI-classified-paper set, and no qualifying case-control result was verified from the available paper extracts.

VCEP rule
Fisher Exact or Chi-Squared analysis shows statistical increase in cases over controls, OR Autosomal dominant: ≥15 probands with variant, and variant meets PM2_Supporting.
Evidence considered
  • VCEP PS4 strong rule: Fisher Exact or Chi-Squared analysis must show a statistical increase in cases over controls; the autosomal-dominant proband-count alternatives do not apply to this autosomal-recessive SLC26A4 context.
  • PMID:24007330, cohort description and abstract: 111 Korean patients from 100 unrelated families had biallelic SLC26A4 mutations, bilateral enlarged vestibular aqueduct, and hearing loss; c.919-2A>G accounted for 24% of alleles in the cohort, but no matched control comparison for this variant was reported in the available extraction.
  • The literature_pass PS4 index listed PMIDs 17718863, 19786220, 20301607, 23151025, 23718755, and 23958391; none was an already-read AI-classified PS4 paper with a verified case-control result in the available packet.
Still missing
  • A matched-ancestry control count or allele frequency for the same study cohort is needed to compute the case-control odds ratio and 95% confidence interval or perform Fisher Exact/Chi-Squared testing.
Sources
PP3 VCEPNot assessed: SpliceAI max delta 0.998 is not the VCEP-named MaxEntScan result, and PP3 is excluded for canonical -2 variants if PVS1 is used. Details ▾Hide ▴
Reasoning

NM_000441.2:c.919-2A>G is a canonical -2 splice variant. The VCEP PP3 rule requires MaxEntScan for splice variants and states not to use PP3 for canonical -/+1 or 2 splice variants when PVS1 is being used. SpliceAI max delta 0.998 predicts splice impact, but SpliceAI is not the predictor named by this rule, and the available group evidence does not establish whether PVS1 is being used; therefore PP3 cannot be resolved under the governing rule.

VCEP rule
REVEL score ≥0.7, or predicted impact to splicing using MaxEntScan. * Use REVEL and MAXENTSCAN. * For missense variants, award PP3 if REVEL score is ≥0.7. * If splicing is predicted to be impacted, either creation of a cryptic splice site, or disruption of a native splice site, award PP3. * For splice variants (except for canonical -/+1 or 2), use MAXENTSCAN. * For -/+ 1 or 2 splice variants, do not use PP3 if you are using PVS1.
Evidence considered
  • VCEP PP3 rule: REVEL score >=0.7, or predicted impact to splicing using MaxEntScan; for splice variants except canonical -/+1 or 2, use MAXENTSCAN; for -/+1 or 2 splice variants, do not use PP3 if using PVS1.
  • Variant consequence facts: NM_000441.2:c.919-2A>G is a canonical splice acceptor (-2) variant.
  • SpliceAI Lookup reports DS_AG 0.001, DS_AL 0.998, DS_DG 0.001, DS_DL 0.925, max delta score 0.998; this predictor is not named in the VCEP PP3 rule and was not used as PP3 evidence.
Still missing
  • MaxEntScan result is unavailable.
  • Whether PVS1 is being used for this canonical -2 splice variant is not specified in the available group evidence.
Sources
PP4 VCEPNot assessed: PP4 requires VCEP Table 7 phenotype-specificity specifications, but those specifications and a complete patient phenotype are unavailable. Details ▾Hide ▴
Reasoning

The VCEP requires the patient's phenotype to be highly specific for the gene or a fully sequenced gene set and directs the evaluator to specifications in Table 7. The available CSPEC criteria entry contains the PP4 rule but does not provide the referenced Table 7 specifications, and the case evidence available here does not provide a complete patient phenotype or a documented fully sequenced gene-set evaluation. A specific PP4 determination therefore cannot be made without the VCEP's Table 7 criteria and complete phenotype data.

VCEP rule
Patient's phenotype highly specific for gene or fully sequenced gene set (see specifications in Table 7).
Evidence considered
  • The VCEP PP4 entry states that the patient's phenotype must be highly specific for the gene or fully sequenced gene set and refers to specifications in Table 7.
  • The available VCEP materials expose the PP4 rule text but no Table 7 content, and the case bundle does not contain a complete patient-specific phenotype assessment for this criterion.
Still missing
  • The VCEP's referenced Table 7 phenotype-specificity specifications are needed.
  • A complete, patient-specific phenotype and any fully sequenced gene-set result are needed for comparison with Table 7.
Sources
BS3 VCEPNot assessed: available RNA studies show abnormal splicing, while no VCEP-specified SLC26A4 assay reports iodide efflux or fluorescence comparable to wild type. Details ▾Hide ▴
Reasoning

No available study demonstrates a benign functional result for c.919-2A>G. The available variant-specific RNA studies instead report abnormal splicing: complete exon 8 skipping with frameshift and premature termination in PMID:15574297, and markedly reduced normal transcript with exon-8-skipped transcript in PMID:24007330. The VCEP's SLC26A4 BS3 supporting rule requires radio-isotope iodide efflux comparable to wild type or fluorescence comparable to wild type; neither result is reported. BS3 therefore cannot be assigned.

VCEP rule
* SLC26A4: Radio isotope and fluorescence assays → BS3_Supporting * Radio Isotope Assays: BS3_Supporting would be applied if the variant results in iodide efflux levels comparable to the wildtype. * Fluorescence assay: BS3_Supporting would be applied if the variant results in fluorescence comparable to the wildtype
Evidence considered
  • Yang et al. 2005, PMID:15574297, RT-PCR and sequencing showed that c.919-2A>G/IVS7-2A>G transcripts skipped exon 8 entirely and generated a new stop codon predicted to produce a 310-amino-acid truncated protein.
  • Choi et al. 2013, PMID:24007330, RNA analysis of homozygous c.919-2A>G showed both exon-8-skipped and normal transcripts, with normal transcript approximately 6% of normal in nasal mucosa and 17% in lymphocytes.
  • ClinGen Hearing Loss Expert Panel CSPEC Version 2.0, BS3 supporting rule: SLC26A4 requires radio-isotope iodide efflux comparable to wild type or fluorescence comparable to wild type; neither assay result is available.
Still missing
  • A VCEP-specified SLC26A4 radio-isotope assay showing iodide efflux comparable to wild type is unavailable.
  • A VCEP-specified SLC26A4 fluorescence assay showing fluorescence comparable to wild type is unavailable.
Sources
BP2 VCEPNot assessed: no qualifying observation of c.919-2A>G in trans with a dominant variant or in cis with a pathogenic variant is documented. Details ▾Hide ▴
Reasoning

BP2 cannot be assessed from the available evidence. The SLC26A4 VCEP rule requires observation in trans with a dominant variant or observation in cis with a pathogenic variant, with caution for genes associated with both dominant and recessive hearing loss. The available reports document compound heterozygous or homozygous SLC26A4 genotypes but do not document the target allele in trans with a dominant variant or in cis with a pathogenic variant.

VCEP rule
Observed in trans with a dominant variant/observed in cis with a pathogenic variant (use with caution). Use with caution. For genes that are associated with both dominant and recessive hearing loss, consider whether an earlier onset/more severe phenotype could be present if variant is identified in trans with a dominant variant.
Evidence considered
  • Lee et al. 2013, PMID:24007330: the reported genotypes are compound heterozygous p.H723R/c.919-2A>G or homozygous c.919-2A>G in affected patients; no dominant SLC26A4 partner or cis pathogenic allele is reported.
  • Yang et al. 2005, PMID:15574297: family studies of four probands with IVS7-2A>G reported parental inheritance and the paper also described homozygous and heterozygous observations, but did not document a qualifying BP2 cis or trans configuration.
  • ClinGen Hearing Loss VCEP CSPEC BP2 rule requires observation in trans with a dominant variant or in cis with a pathogenic variant and advises caution for genes associated with both dominant and recessive hearing loss.
Still missing
  • Phased observation of c.919-2A>G in cis with a pathogenic variant or in trans with a dominant variant is not available.
Sources
BP4 VCEPNot assessed: REVEL is unavailable and no MaxEntScan result establishes no splice impact; SpliceAI max delta 0.998 is not the VCEP-named predictor. Details ▾Hide ▴
Reasoning

The VCEP BP4 rule permits computational no-impact evidence through REVEL <=0.15 or no impact to splicing in MaxEntScan. REVEL is unavailable, and no MaxEntScan result is available. SpliceAI max delta 0.998 predicts splice impact but is not the predictor named by the governing rule, so BP4 cannot be assessed from the available rule-valid evidence.

VCEP rule
Computational evidence suggests no impact; REVEL score ≤0.15 or no impact to splicing in MaxEntScan.
Evidence considered
  • VCEP BP4 rule: computational evidence suggests no impact when REVEL score is <=0.15 or there is no impact to splicing in MaxEntScan.
  • Prefetch reports no REVEL score for NM_000441.2:c.919-2A>G.
  • SpliceAI Lookup reports max delta score 0.998, indicating predicted splice impact; SpliceAI is not named in the VCEP BP4 rule and was not used to evaluate BP4.
Still missing
  • REVEL score is unavailable.
  • MaxEntScan splice-impact result is unavailable.
Sources
Not applicable · 9· recorded as not applicable Show reasons ▾Hide reasons ▴
PM1 N/ANot applicable: the VCEP PM1 specification covers only KCNQ4 missense variants at amino acids 271-292, not SLC26A4 c.919-2A>G. Details ▾Hide ▴
Reasoning

The VCEP's only PM1 specification in the governing CSPEC is limited to missense variants in the KCNQ4 pore-forming region at amino acids 271-292. This case is SLC26A4 c.919-2A>G, a canonical splice variant, and vcep_materials.json contains no SLC26A4 domain-table entry. The specified KCNQ4 route therefore does not apply.

VCEP rule
Mutational hot spot or well-studied functional domain without benign variation (KCNQ4 pore-forming region). * KCNQ4 (NM_004700.4) gene - missense variants located within amino acids 271-292 can be awarded PM1. This region is the pore-forming intramembrane region where many variants that cause autosomal dominant hearing loss are located (Naito et al. 2013, PMID: 23717403; https://www.uniprot.org/uniprot/P56696). There are only two missense variants in this region in gnomAD, each with only single allele (http://gnomad.broadinstitute.org/; rs763326539: 1/33578 Latino chromosomes; rs55737429: 1/111720 European chromosomes).
Evidence considered
  • VCEP CSPEC PM1 specifies the KCNQ4 pore-forming region, amino acids 271-292, as the applicable region.
  • The case variant is NM_000441.2:c.919-2A>G in SLC26A4 and is classified as a canonical splice variant.
  • vcep_materials.json has no SLC26A4 domain_tables entry.
Sources
PM4 N/ANot applicable: this is a splice-site substitution, whereas PM4 requires an in-frame insertion or deletion causing a protein length change. Details ▾Hide ▴
Reasoning

The variant is a canonical splice-site substitution, not an in-frame deletion or insertion producing a protein length change. The PM4 rule therefore does not apply.

VCEP rule
Protein length change due to an in-frame deletion or insertion that are not located in repetitive regions. * No changes. Follow recommendations as outlined in ACMG/AMP guidelines and/or Sequence Variant Interpretation working group.
Evidence considered
  • PVS1 variant assessment classifies NM_000441.2:c.919-2A>G as a canonical splice variant with protein consequence p.?; it is not an in-frame insertion or deletion.
Sources
cspec ↗pvs1_variant_assessment
PM5 N/ANot applicable: PM5 requires a missense codon comparison, but c.919-2A>G is a canonical splice variant with protein consequence p.?. Details ▾Hide ▴
Reasoning

The VCEP PM5 rule is restricted to a missense change at the same codon as one or more pathogenic missense variants. This case is NM_000441.2:c.919-2A>G, a canonical splice variant with protein consequence p.?, so it has no amino-acid codon or residue on which the PM5 rule can operate. The PM5 candidate collection likewise found no eligible same-residue missense candidates.

VCEP rule
Missense change at same codon as two different pathogenic missense variants. * Located at an amino acid residue with known pathogenic variation (at least 2 other variants at the same site meet pathogenic criteria for based on independent data) * Caveat: Assess whether the variants in question could have an impact at the DNA level, such as through splicing impacts. Missense change at same codon as another pathogenic missense variant. No changes. Follow recommendations as outlined in ACMG/AMP guidelines and/or Sequence Variant Interpretation working group.
Evidence considered
  • VCEP CSPEC PM5 requires a missense change at the same codon as another pathogenic missense variant, with a stronger option requiring two such variants.
  • Case normalization gives NP_000432.1:p.? and identifies the variant consequence class as canonical_splice.
  • The PM5 comparator collection reports zero eligible candidates because the variant is not missense.
Sources
cspec ↗pm5_candidates
PP2 VCEPNot applicable: the VCEP excludes PP2 for this gene. Details ▾Hide ▴
Reasoning

The ClinGen Hearing Loss Expert Panel Specifications to the ACMG/AMP Variant Interpretation Guidelines for CDH23, COCH, GJB2, KCNQ4, MYO6, MYO7A, SLC26A4, TECTA and USH2A Version 2.0 marks PP2 as not applicable. The VCEP states: "Advise against using this rule because there are few such genes that this would apply to, particularly genes associated to autosomal recessive hearing loss." NM_000441.2:c.919-2A>G in SLC26A4 is a variant at a canonical ±1/2 splice-consensus position predicted to produce NP_000432.1:p.?. This determination was made deterministically from the VCEP criteria specification, prior to LLM adjudication.

VCEP rule
deterministic_prefilter: vcep_not_applicable
Evidence considered
  • Deterministic consequence classification: canonical_splice (prefetch.json normalized protein consequence)
  • VCEP criterion policy: vcep_not_applicable
Sources
BP1 VCEPNot applicable: the VCEP excludes BP1 for this gene. Details ▾Hide ▴
Reasoning

The ClinGen Hearing Loss Expert Panel Specifications to the ACMG/AMP Variant Interpretation Guidelines for CDH23, COCH, GJB2, KCNQ4, MYO6, MYO7A, SLC26A4, TECTA and USH2A Version 2.0 marks BP1 as not applicable. NM_000441.2:c.919-2A>G in SLC26A4 is a variant at a canonical ±1/2 splice-consensus position predicted to produce NP_000432.1:p.?. This determination was made deterministically from the VCEP criteria specification, prior to LLM adjudication.

VCEP rule
deterministic_prefilter: vcep_not_applicable
Evidence considered
  • Deterministic consequence classification: canonical_splice (prefetch.json normalized protein consequence)
  • VCEP criterion policy: vcep_not_applicable
Sources
BP3 N/ANot applicable: BP3 requires an in-frame indel in a repeat region without known function, but this variant is a canonical splice-site substitution. Details ▾Hide ▴
Reasoning

The variant is a canonical splice-site substitution, not an in-frame indel. It therefore does not meet the VCEP's variant-type applicability requirement for BP3, regardless of whether a repeat region is documented.

VCEP rule
In-frame indels in repeat region without known function. No changes. Follow recommendations as outlined in Richard 2015 and/or ClinGen's Sequence Variant Interpretation working group.
Evidence considered
  • PVS1 variant assessment classifies NM_000441.2:c.919-2A>G as a canonical splice variant; no in-frame insertion or deletion is present.
Sources
cspec ↗pvs1_variant_assessment
BP5 N/ANot applicable: the VCEP expressly says not to use BP5 for autosomal-recessive SLC26A4 because carrier status can coexist with another cause. Details ▾Hide ▴
Reasoning

The VCEP BP5 rule states that an autosomal-recessive variant in a patient with an alternate cause must not receive BP5, because the individual could be a carrier of a pathogenic variant and have an alternate cause. SLC26A4 is specified as autosomal recessive in the governing VCEP framework, so BP5 is not applicable even if an alternate explanation were documented.

VCEP rule
Variant in an autosomal dominant gene found in a patient with an alternate explanation. * Autosomal recessive: Do not use. An individual could be carrier of pathogenic variant and have an alternate cause. Therefore, BP5 shouldn’t be used as evidence for benign in this case. * Autosomal dominant: Can use BP5 as outlined by Richards 2015. * Caveat: consider whether multiple pathogenic autosomal dominant variants could cause a more severe phenotype or whether multigenic inheritance is known to occur (example: Bardet-Biedl syndrome).
Evidence considered
  • The VCEP BP5 rule says: Autosomal recessive: Do not use. An individual could be carrier of pathogenic variant and have an alternate cause. Therefore, BP5 shouldn't be used as evidence for benign in this case.
  • The VCEP raw gene context specifies SLC26A4 with autosomal-recessive Pendred syndrome.
Sources
BP6 VCEPNot applicable: this VCEP explicitly prohibits BP6, regardless of benign reports from reputable sources. Details ▾Hide ▴
Reasoning

The VCEP marks BP6 as not applicable for this VCEP and states that the criterion is not for use as recommended by the ClinGen Sequence Variant Interpretation VCEP Review Committee. Reputable-source classifications therefore cannot be used to apply BP6 under the governing framework.

VCEP rule
This criterion is not for use as recommended by the ClinGen Sequence Variant Interpretation VCEP Review Committee.
Evidence considered
  • The VCEP BP6 entry is marked Not Applicable for this VCEP and instructs: This criterion is not for use as recommended by the ClinGen Sequence Variant Interpretation VCEP Review Committee.
Sources
BP7 N/ANot applicable: NM_000441.2:c.919-2A>G is a canonical intronic splice-site variant, not a silent variant required by the VCEP BP7 rule. Details ▾Hide ▴
Reasoning

BP7 is limited by the VCEP rule to silent variants with no predicted impact to splicing. NM_000441.2:c.919-2A>G is a canonical intronic splice-site variant with predicted protein consequence p.?, not a silent coding variant; BP7 is therefore outside its governing scope.

VCEP rule
Silent variant with no predicted impact to splicing. No changes. Follow recommendations as outlined in Richard 2015 and/or ClinGen's Sequence Variant Interpretation working group.
Evidence considered
  • Variant normalization identifies NM_000441.2:c.919-2A>G as a canonical splice acceptor (-2) variant with protein consequence NP_000432.1:p.?.
  • The VCEP BP7 applicability text is restricted to silent variants with no predicted impact to splicing.
Sources

Identifiers

Gene
SLC26A4
Transcript
NM_000441.2
Coding (HGVS c.)
NM_000441.2:c.919-2A>G
Protein (HGVS p.)
NP_000432.1:p.?
GRCh38
chr7:107683453 A>G
GRCh37
chr7:107323898 A>G
Location and type
Intron 7 · canonical splice
ClinVar
4840, 4686660, 1698554, 1331489, 627475, 558599, 417623, 4825

Gene diagram

Every interpreted variant in SLC26A4, mapped onto the exon structure of NM_000441.2. Select a row to find it on the plot.

SLC26A4NM_000441.2
Fetching transcript structure from UCSC…
gnomAD v4.1 125 / 1,613,754 alleles AF 7.75e-05 · 0 homozygotes · FAF 0.00224
gnomAD v2.1 103 / 282,410 alleles AF 0.000365 · 0 homozygotes · FAF 0.00493
gnomAD-Canada v1.0 Allele count data not recorded

By genetic ancestry

gnomAD v4.1

AF 7.7e-05 · 125 / 1,613,754 alleles · 0 hom · FAF 0.0022
East Asian118 / 44,866 0.0026
Middle Eastern1 / 6,060 0.00017
Remaining individuals3 / 62,488 4.8e-05
South Asian1 / 91,080 1.1e-05
European (non-Finnish)2 / 1,179,700 1.7e-06
0 alternate alleles recorded in 5 other groups: Admixed American, European (Finnish), Amish, Ashkenazi Jewish, African/African American.

gnomAD v2.1

AF 0.00036 · 103 / 282,410 alleles · 0 hom · FAF 0.0049
East Asian101 / 19,946 0.0051
European (non-Finnish)2 / 128,880 1.6e-05
0 alternate alleles recorded in 6 other groups: African/African American, Admixed American, Ashkenazi Jewish, European (Finnish), Remaining individuals, South Asian.

Statements

gnomAD v4.1

This variant is present in gnomAD v4.1 (AF= 7.74591e-05; MAF= 0.00775%, 125/1613754 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.00263005; MAF= 0.26301%, 118/44866 alleles, homozygotes = 0); grpmax FAF= 0.0022441.

gnomAD v2.1

This variant is present in gnomAD v2.1 (AF= 0.000364718; MAF= 0.03647%, 103/282410 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.00506367; MAF= 0.50637%, 101/19946 alleles, homozygotes = 0); grpmax FAF= 0.00492851.

gnomAD-Canada

Not available in gnomAD-Canada v1.0.

SpliceAI and Pangolin

SpliceAI acceptor lossat +2 bp
0.998
SpliceAI acceptor gainat +33 bp
0.001
SpliceAI donor lossat +84 bp
0.925
SpliceAI donor gainat -108 bp
0.001
Pangolin splice lossmagnitude shown
-0.883
Pangolin splice gain
0.014

Other predictors

REVEL
Not available
BayesDel
0.660

How the predictions were used

PP3 VCEPNot assessed: SpliceAI max delta 0.998 is not the VCEP-named MaxEntScan result, and PP3 is excluded for canonical -2 variants if PVS1 is used. Details ▾Hide ▴
Reasoning

NM_000441.2:c.919-2A>G is a canonical -2 splice variant. The VCEP PP3 rule requires MaxEntScan for splice variants and states not to use PP3 for canonical -/+1 or 2 splice variants when PVS1 is being used. SpliceAI max delta 0.998 predicts splice impact, but SpliceAI is not the predictor named by this rule, and the available group evidence does not establish whether PVS1 is being used; therefore PP3 cannot be resolved under the governing rule.

VCEP rule
REVEL score ≥0.7, or predicted impact to splicing using MaxEntScan. * Use REVEL and MAXENTSCAN. * For missense variants, award PP3 if REVEL score is ≥0.7. * If splicing is predicted to be impacted, either creation of a cryptic splice site, or disruption of a native splice site, award PP3. * For splice variants (except for canonical -/+1 or 2), use MAXENTSCAN. * For -/+ 1 or 2 splice variants, do not use PP3 if you are using PVS1.
Evidence considered
  • VCEP PP3 rule: REVEL score >=0.7, or predicted impact to splicing using MaxEntScan; for splice variants except canonical -/+1 or 2, use MAXENTSCAN; for -/+1 or 2 splice variants, do not use PP3 if using PVS1.
  • Variant consequence facts: NM_000441.2:c.919-2A>G is a canonical splice acceptor (-2) variant.
  • SpliceAI Lookup reports DS_AG 0.001, DS_AL 0.998, DS_DG 0.001, DS_DL 0.925, max delta score 0.998; this predictor is not named in the VCEP PP3 rule and was not used as PP3 evidence.
Still missing
  • MaxEntScan result is unavailable.
  • Whether PVS1 is being used for this canonical -2 splice variant is not specified in the available group evidence.
Sources
BP4 VCEPNot assessed: REVEL is unavailable and no MaxEntScan result establishes no splice impact; SpliceAI max delta 0.998 is not the VCEP-named predictor. Details ▾Hide ▴
Reasoning

The VCEP BP4 rule permits computational no-impact evidence through REVEL <=0.15 or no impact to splicing in MaxEntScan. REVEL is unavailable, and no MaxEntScan result is available. SpliceAI max delta 0.998 predicts splice impact but is not the predictor named by the governing rule, so BP4 cannot be assessed from the available rule-valid evidence.

VCEP rule
Computational evidence suggests no impact; REVEL score ≤0.15 or no impact to splicing in MaxEntScan.
Evidence considered
  • VCEP BP4 rule: computational evidence suggests no impact when REVEL score is <=0.15 or there is no impact to splicing in MaxEntScan.
  • Prefetch reports no REVEL score for NM_000441.2:c.919-2A>G.
  • SpliceAI Lookup reports max delta score 0.998, indicating predicted splice impact; SpliceAI is not named in the VCEP BP4 rule and was not used to evaluate BP4.
Still missing
  • REVEL score is unavailable.
  • MaxEntScan splice-impact result is unavailable.
Sources
BP7 N/ANot applicable: NM_000441.2:c.919-2A>G is a canonical intronic splice-site variant, not a silent variant required by the VCEP BP7 rule. Details ▾Hide ▴
Reasoning

BP7 is limited by the VCEP rule to silent variants with no predicted impact to splicing. NM_000441.2:c.919-2A>G is a canonical intronic splice-site variant with predicted protein consequence p.?, not a silent coding variant; BP7 is therefore outside its governing scope.

VCEP rule
Silent variant with no predicted impact to splicing. No changes. Follow recommendations as outlined in Richard 2015 and/or ClinGen's Sequence Variant Interpretation working group.
Evidence considered
  • Variant normalization identifies NM_000441.2:c.919-2A>G as a canonical splice acceptor (-2) variant with protein consequence NP_000432.1:p.?.
  • The VCEP BP7 applicability text is restricted to silent variants with no predicted impact to splicing.
Sources

Statement

In silico

SpliceAI predicts possible splice impact for this variant (max delta score = 1.00). BayesDel score = 0.66.

8 paper records listed. 5 cited in the classification.

Cited in the classification

  • Identification of two different mutations in the PDS gene in an inbred family with Pendred syndrome.
    Coucke PJ et al. · 1999 Jun
    The paper reports an extended inbred Turkish family with Pendred syndrome. Most affected patients were homozygous for the reported splice-site mutation, while two affected siblings with non-consanguineous parents were compound heterozygotes for the splice-site mutation and a missense mutation, providing familial segregation evidence rather than de novo evidence.
    → PP1 · supporting Names this variant
    PMID 10874637 ↗
    Source detail
    The majority of patients in this family are homozygous for a splice site mutation (1143-2A-->G) affecting the 3' splice site consensus sequence of intron 7. However, two affected sibs with non-consanguineous parents are compound heterozygotes for the splice site mutation and a missense mutation (1558T-->G), substituting an evolutionarily conserved

    Location Abstract

    Context Extended inbred Turkish Pendred syndrome family with molecular analysis of PDS mutations and affected-relative observations.

  • Two Chinese families with Pendred's syndrome--radiological imaging of the ear and molecular analysis of the pendrin gene.
    Yong AM et al. · 2001 Aug
    The paper reports two Pendred syndrome families with hearing loss and enlarged vestibular aqueduct findings. Family I included two deaf siblings and one normal sibling; family II included two deaf offspring and deaf parents, providing family-level segregation context for the reported SLC26A4 variant.
    → PP1 · supporting Names this variant
    PMID 11502831 ↗
    Source detail
    In family I, two siblings were deaf, and one was normal. In family II, both parents and two offspring were deaf.

    Location Abstract

    Context Two Chinese Pendred syndrome families assessed by clinical examination, temporal-bone CT, and molecular analysis of the pendrin gene.

  • Hearing loss associated with enlarged vestibular aqueduct and Mondini dysplasia is caused by splice-site mutation in the PDS gene.
    Yang JJ et al. · 2005 Jan
    The exact SLC26A4 splice-site variant NM_000441.2:c.919-2A>G was evaluated by RT-PCR and demonstrated complete skipping of exon 8, producing a frameshift and premature termination.
    → PVS1 · very strong Names this variant
    PMID 15574297 ↗
    Source detail
    Deletion of the exon 8 results in frameshift and premature termination of translation.

    Location Abstract, lines 20–21; Results, Fig. 4 description, lines 291–296

    Context RT-PCR analysis of RNA from patients with SLC26A4-related hearing loss and splice-site mutations.

  • [Genotypic analysis of familial dilated vestibular aqueduct syndrome].
    Dai P et al. · 2006 Feb
    The paper analyzes two familial DVAS pedigrees. The twin sisters in one pedigree and a brother and sister in the other had sensorineural hearing loss and enlarged vestibular aqueducts, and the reported SLC26A4 splice-site variant was evaluated by direct sequencing.
    → PP1 · supporting Names this variant
    PMID 16711435 ↗
    Source detail
    The twin sisters from pedigree and the brother and sister from pedigree 2 all suffered from sensorineural hearing loss. All patients from these two families were confirmed to have enlarged vestibular aqueduct by temporal bone CT scan.

    Location Abstract

    Context Two familial DVAS pedigrees assessed by temporal-bone CT, direct sequencing of exons 7 and 8 with flanking regions, and DHPLC screening of other exons.

  • Correlation between genotype and phenotype in patients with bi-allelic SLC26A4 mutations.
    The exact SLC26A4 c.919-2A>G variant was studied in patients with biallelic disease; RNA analysis detected both exon-8-skipped and normally spliced transcripts, with normal transcript levels approximately 6% of normal in nasal mucosa and 17% in lymphocytes, showing leaky splice-site activity.
    → PVS1 · very strong → PM3 · moderate Names this variant
    PMID 24007330 ↗
    Source detail
    In two patients homozygous for c.919-2A>G, RNA analysis detected both transcripts lacking exon 8 and normally spliced transcripts; normal transcripts were approximately 6% of normal in nasal mucosa and 17% in lymphocytes.

    Location Results, mRNA transcripts in patients with c.919-2A>G homozygous mutation; Discussion

    Context 111 Korean patients from 100 unrelated families with biallelic SLC26A4 mutations; RT-PCR, sequencing, and quantitative real-time PCR of nasal mucosa and lymphocyte RNA from two homozygous individuals.

Other recorded publications

  • Pendred syndrome and DFNB4-mutation screening of SLC26A4 by denaturing high-performance liquid chromatography and the identification of eleven novel mutations.
    Prasad S et al. · 2004
    No paper-specific finding is recorded.
    PMID 14679580 ↗
  • Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.
    No paper-specific finding is recorded.
    PMID 25741868 ↗
  • Global genetic insight contributed by consanguineous Pakistani families segregating hearing loss.
    No paper-specific finding is recorded.
    PMID 30303587 ↗

Screenshots represent source records captured during evidence collection. Select one to view the recorded source content.

All source links

Statements for reports

The evidence statements recorded by the interpretation pipeline. They have not been reinterpreted by the page.

gnomAD v4.1

This variant is present in gnomAD v4.1 (AF= 7.74591e-05; MAF= 0.00775%, 125/1613754 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.00263005; MAF= 0.26301%, 118/44866 alleles, homozygotes = 0); grpmax FAF= 0.0022441.

gnomAD v2.1

This variant is present in gnomAD v2.1 (AF= 0.000364718; MAF= 0.03647%, 103/282410 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.00506367; MAF= 0.50637%, 101/19946 alleles, homozygotes = 0); grpmax FAF= 0.00492851.

gnomAD-Canada

Not available in gnomAD-Canada v1.0.

ClinVar

This variant has been reported in ClinVar as Pathogenic (27 clinical laboratories) and as Affects (1 clinical laboratory) and as Pathogenic by ClinGen Hearing Loss Variant Curation Expert Panel (expert panel). (ClinVarID = 4840)

In silico

SpliceAI predicts possible splice impact for this variant (max delta score = 1.00). BayesDel score = 0.66.

Somatic

This variant has not previously been reported in somatic cancers (COSMIC).