0%
complete
Final classification
VUS
PM2
ARID1A
c.673C>T
p.Pro225Ser
missense · exon 1

ARID1A encodes a component of the SWI/SNF chromatin-remodeling complex, which regulates gene expression by altering chromatin structure around target genes. It binds AT-rich DNA sequences and helps recruit the remodeling complex to its targets. Germline mutations in ARID1A cause Coffin-Siris syndrome, a condition marked by developmental delay and coarse facial features. ARID1A also acts as a tumor suppressor in several cancer types, including gynecologic cancers, ovarian clear cell carcinomas, and endometrial cancers.

This variant

ARID1A encodes a SWI/SNF chromatin-remodeling complex component involved in gene regulation and is associated with Coffin-Siris syndrome when altered in the germline.

Transcript
NM_006015.5
HGVS · transcript:coding
NM_006015.5:c.673C>T
GRCh38
chr1:26697076 C>T
GRCh37
chr1:27023567 C>T
VUS: PM2 (supporting) for extreme rarity is the only applied criterion and does not meet generic ACMG/AMP thresholds for a definitive classification.
Classification rationale
PM2 VUS
ARID1A c.673C>T missense · exon 1

PM2 supporting: gnomAD v4.1 shows extreme rarity at 4/1,496,722 alleles (AF 2.67251e-06) with zero homozygotes.

PM2 VUS
Gene diagram · NM_006015.5 · variants mapped to exon structure
ARID1A NM_006015.5
Fetching transcript structure from UCSC…
Applied criteria · 1 applied · 23 assessed
MetEvidence satisfies this criterion.
Not metEvaluated against available evidence; threshold not reached.
Not assessedApplies in principle, but no evidence was found to evaluate it.
N/ADoesn't apply to this variant type.
Applied · 1
Strength Supporting Moderate Strong Very strong
PM2 supporting Pathogenic
Met at supporting strength: gnomAD v4.1 shows 4/1,496,722 alleles (AF 2.67251e-06), zero homozygotes, and grpmax FAF 3.804e-05.
No official CSPEC/VCEP or local ARID1A-specific population framework was available; generic ACMG/AMP criteria were used.gnomAD v2.1 exomes: variant absent.The case data report absence from gnomAD v2.1 non-cancer and gnomAD v3.1 non-cancer subset queries.
Assessed · not applied · 6 not met · 17 not assessed
Pathogenic
PS1 Not assessed: no validated pathogenic comparator producing the same p.Pro225Ser amino-acid change was identified.
PS2 Not assessed: no proband phenotype, parental genotypes, maternity/paternity confirmation, or independent confirmed de novo observations are documented.
PS3 Not assessed: no variant-specific validated functional assay, assay controls, or quantitative result was available to support a damaging functional conclusion.
PS4 Not assessed: no exact-variant case-control counts or enrichment statistic are available to establish increased prevalence of ARID1A c.673C>T.
PM1 Not assessed: hotspot evidence is negative, while no authoritative ARID1A domain boundaries establish whether residue 225 is functionally critical.
PM3 Not assessed: no affected proband, second pathogenic variant, phase information, or inheritance mode is documented for the tested ARID1A variant.
PM5 Not assessed: no validated pathogenic alternate missense variant at ARID1A residue 225 was available for PM5 comparison.
PM6 Not assessed: no affected-proband de novo observation or parental testing is documented, so presumed de novo evidence cannot be evaluated.
PP1 Not assessed: no relatives, informative meioses, pedigree, or variant–phenotype segregation data are reported.
PP2 Not met: ARID1A missense mechanism is unestablished, and gnomAD v4.1 shows AF 2.67251e-06 without proving PP2's gene-level requirement.
PP3 Not assessed: the missense variant lacks an available calibrated REVEL or BayesDel score, while SpliceAI is not the applicable path for this exonic missense change.
PP4 Not assessed: no proband phenotype or disease-specific clinical presentation is available to evaluate phenotype specificity for ARID1A c.673C>T.
PP5 Not met: ClinVar has no record for this exact variant, so no expert-panel Pathogenic or Likely pathogenic classification exists to support PP5.
Benign
BA1 Not met: gnomAD v4.1 maximum reported population AF is 1.11788e-04, far below the generic BA1 threshold of 5%.
BS1 Not met: gnomAD v4.1 grpmax FAF is 3.804e-05, with no frequency evidence showing the variant is too common for a rare ARID1A disorder.
BS2 Not met: gnomAD v4.1 reports zero homozygotes and only 4 total alleles, providing no required healthy-adult observation pattern for BS2.
BS3 Not assessed: no variant-specific validated functional assay, assay controls, or quantitative result was available to support a benign functional conclusion.
BS4 Not assessed: no unaffected relatives with reliable phenotypes and genotypes are available to evaluate non-segregation.
BP1 Not assessed: ARID1A loss-of-function evidence does not quantify whether disease is predominantly truncating, and gnomAD AF is 2.67251e-06.
BP2 Not assessed: no paired pathogenic allele, family or proband observation, phase result, or inheritance mode is documented to evaluate BP2.
BP4 Not assessed: the missense variant lacks an available calibrated REVEL or BayesDel score, while SpliceAI is not the applicable path for this exonic missense change.
BP5 Not assessed: no alternate molecular diagnosis or other proband-level evidence is available to determine whether another cause explains the phenotype.
BP6 Not met: ClinVar has no record for this exact variant, so no expert-panel Benign or Likely benign classification exists to support BP6.
N/A · 4 PVS1 · PM4 · BP3 · BP7
Research & evidence
Population frequency
gnomAD v4.1 screenshot
gnomAD v4.1
gnomAD v2.1 screenshot
gnomAD v2.1
v4.1
This variant is present in gnomAD v4.1 (AF= 2.67251e-06; MAF= 0.00027%, 4/1496722 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.000111788; MAF= 0.01118%, 4/35782 alleles, homozygotes = 0); grpmax FAF= 3.804e-05.
v2.1
Absent from gnomAD v2.1.
🇨🇦 CA
Absent from gnomAD-Canada v1.0.
Allele frequency by ancestry
three datasets · side by side
gnomAD v4.1
0.00027% · 4 / 1,496,722
0 hom · FAF 0.0038%
East Asian
4 / 35,782
0.011%
+ 9 not observed (Remaining individuals, Admixed American, European (Finnish), Amish, Middle Eastern, South Asian, Ashkenazi Jewish, African/African American, European (non-Finnish))
gnomAD v2.1
Absent · 0 / ?
0 hom
Not observed in any ancestry group.
gnomAD Canada 🇨🇦
Absent · 0 / ?
0 hom
Not observed in any ancestry group.
ClinVar screenshot
ClinVar
This variant is absent from ClinVar.
SpliceAI screenshot
In silico
SpliceAI predicts no significant splice impact for this variant (max delta score = 0.00).
Functional / OncoKB screenshot
Functional Unknown Oncogenic Effect
OncoKB did not identify variant-specific reviewed functional evidence for this variant; gene-level curated context is available for reviewer follow-up. ARID1A, a tumor suppressor involved in transcriptional regulation, is inactivated by mutation in various cancer types including endometrial and bladde
OncoKB ↗
COSMIC screenshot
COSMIC
Cancer hotspots screenshot
Cancer hotspots
Somatic evidence Not in COSMIC / hotspots
COSMIC
This variant does not lie in a statistically significant hotspot. This variant has not previously been reported in somatic cancers (COSMIC).
Hotspots
This variant does not lie in a statistically significant hotspot.
Sources & reference links
8Sources
ClinVar
gnomAD v2.1
gnomAD v4.1
gnomAD-Canada
SpliceAI
OncoKB
COSMIC
Cancer hotspots