ASXL1 c.2269C>T, p.Gln757Ter
NM_015338.5:c.2269C>T
COSM7208198
Population Frequency
0.000398%
Rare
ClinVar Classification
Unknown
0 publications
REVEL Score
N/A
Not Available
COSMIC Recurrence
5 occurrences
No Criteria Applied
Classification Evidence
Detailed Information
Genetic Information
Gene & Transcript Details
Gene
ASXL1
Transcript
NM_015338.6
MANE Select
Total Exons
13
Strand
Forward (+)
Reference Sequence
NC_000020.10
Alternative Transcripts
| ID | Status | Details |
|---|---|---|
| NM_015338.5 | RefSeq Select | 13 exons | Forward |
| NM_015338.4 | Alternative | 13 exons | Forward |
| NM_015338.3 | Alternative | 13 exons | Forward |
Variant Details
HGVS Notation
NM_015338.5:c.2269C>T
Protein Change
Q757*
Location
Exon 13
(Exon 13 of 13)
5'
Exon Structure (13 total)
3'
Functional Consequence
Loss of Function
Related Variants
Alternate Identifiers
COSM7208198
Variant interpretation based on transcript NM_015338.6
Clinical Evidence
Global Frequency
0.000398%
Extremely Rare
Highest in Population
European (non-Finnish)
0.00088%
Very Rare
Global: 0.000398%
European (non-Finnish): 0.00088%
0%
0.0005%
0.001%
0.01%
0.05%
1%+
Allele Information
Total: 251358
Alt: 1
Homozygotes: 0
ACMG Criteria Applied
PM2
This variant is present in gnomAD (MAF= 0.000398%, 1/251358 alleles, homozygotes = 0) and at a higher frequency in the European (non-Finnish) population (MAF= 0.00088%, 1/113674 alleles, homozygotes = 0). The variant is rare (MAF < 0.1%), supporting PM2 criterion application.
Classification
Unknown
Publications
0 publications
Clinical Statement
Functional Domain
Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain (0 mutations).
Related Variants in This Domain
Functional Studies
Summary
The ASXL1 Q757* variant is a truncating mutation that results in the loss of the PHD domain, leading to the production of C-terminally truncated proteins. Functional studies have demonstrated that expression of ASXL1 truncating mutations in murine myeloid cells causes dedifferentiation and myelodysplastic syndrome in a bone marrow transplant mouse model, supporting a damaging effect.
Computational Evidence
Pathogenicity Predictions
Predictor Consensus
Mixed/VUS
PP3 Applied
No
Additional Predictors
Benign:
CADD: 8.59
Neutral:
Show all
VCEP Guidelines
Applied ACMG/AMP Criteria
PVS1
PVS1 (Very Strong)
According to standard ACMG guidelines, the rule for PVS1 is: "Null variant in a gene where loss of function (LoF) is a known mechanism of disease (e.g., nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single exon deletion in a LoF gene)". The evidence for this variant shows: NM_015338.5:c.2269C>T is a nonsense variant predicted to result in loss of function in ASXL1, a gene where LoF is a known disease mechanism and it is not located in the last exon. Therefore, this criterion is applied at Very Strong strength because it is a null variant in a gene with a known LoF mechanism of disease.
PS1
PS1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PS1 is: "Same amino acid change as a known pathogenic variant but different nucleotide change". The evidence for this variant shows: there is no report of another pathogenic variant causing the same Q757* change by a different nucleotide change. Therefore, this criterion is not applied.
PS2
PS2 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PS2 is: "De novo (both maternity and paternity confirmed) in a patient with the disease and no family history". The evidence for this variant shows: no de novo occurrence data are available. Therefore, this criterion is not applied.
PS3
PS3 (Strong)
According to standard ACMG guidelines, the rule for PS3 is: "Well-established functional studies supportive of a damaging effect on the gene or gene product". The evidence for this variant shows: functional studies demonstrate that ASXL1 truncating mutations like Q757* cause dedifferentiation and myelodysplastic syndrome in a bone marrow transplant mouse model. Therefore, this criterion is applied at Strong strength because well-established in vivo studies support a damaging effect.
PS4
PS4 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PS4 is: "Prevalence in affected individuals significantly increased compared with controls". The evidence for this variant shows: no case-control data demonstrating significant enrichment in affected individuals. Therefore, this criterion is not applied.
PM1
PM1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PM1 is: "Located in a mutational hot spot or well-established functional domain without benign variation". The evidence for this variant shows: although Q757* disrupts the PHD domain, no specific domain hotspot guidance is established for ASXL1. Therefore, this criterion is not applied.
PM2
PM2 (Moderate)
According to standard ACMG guidelines, the rule for PM2 is: "Absent from controls (or at extremely low frequency if recessive)". The evidence for this variant shows: gnomAD reports a MAF of 0.000398% with no homozygotes, supporting rarity. Therefore, this criterion is applied at Moderate strength because the variant is extremely rare in population databases.
PM3
PM3 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PM3 is: "Detected in trans with a pathogenic variant (for recessive disorders)". The evidence for this variant shows: ASXL1-associated disease is dominant and no trans variants are reported. Therefore, this criterion is not applied.
PM4
PM4 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PM4 is: "Protein length changes due to in-frame deletions/insertions or stop-loss variants". The evidence for this variant shows: Q757* is a nonsense variant, not an in-frame indel or stop-loss. Therefore, this criterion is not applied.
PM5
PM5 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PM5 is: "Novel missense change at an amino acid residue where a different pathogenic missense change has been seen". The evidence for this variant shows: Q757* is not a missense change. Therefore, this criterion is not applied.
PM6
PM6 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PM6 is: "Assumed de novo, but without confirmation of paternity and maternity". The evidence for this variant shows: no de novo data. Therefore, this criterion is not applied.
PP1
PP1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PP1 is: "Co-segregation with disease in multiple affected family members". The evidence for this variant shows: no segregation data available. Therefore, this criterion is not applied.
PP2
PP2 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PP2 is: "Missense variant in a gene with a low rate of benign missense variation and where missense variants are a common mechanism of disease". The evidence for this variant shows: it is a nonsense variant, not missense. Therefore, this criterion is not applied.
PP3
PP3 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PP3 is: "Multiple lines of computational evidence support a deleterious effect on the gene/gene product (e.g., conservation, splicing impact)". The evidence for this variant shows: computational tools (CADD score 8.59, SpliceAI 0.01) do not predict a deleterious effect. Therefore, this criterion is not applied.
PP4
PP4 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PP4 is: "Patient's phenotype or family history highly specific for a disease with a single genetic etiology". The evidence for this variant shows: no phenotype or family history provided. Therefore, this criterion is not applied.
PP5
PP5 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for PP5 is: "Reputable source reports variant as pathogenic, but without accessible evidence". The evidence for this variant shows: not reported in ClinVar or other sources. Therefore, this criterion is not applied.
BA1
BA1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BA1 is: "Allele frequency is too high for the disorder (based on population data)". The evidence for this variant shows: MAF is 0.000398%, below thresholds. Therefore, this criterion is not applied.
BS1
BS1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BS1 is: "Allele frequency is greater than expected for the disorder". The evidence for this variant shows: frequency is extremely low. Therefore, this criterion is not applied.
BS2
BS2 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BS2 is: "Observed in healthy individuals with full penetrance expected at an early age". The evidence for this variant shows: no data in healthy cohorts. Therefore, this criterion is not applied.
BS3
BS3 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BS3 is: "Well-established functional studies show no damaging effect on protein function or splicing". The evidence for this variant shows: functional studies demonstrate a damaging effect. Therefore, this criterion is not applied.
BS4
BS4 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BS4 is: "Lack of segregation in affected family members". The evidence for this variant shows: no segregation data. Therefore, this criterion is not applied.
BP1
BP1 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP1 is: "Missense variant in a gene where only LoF causes disease". The evidence for this variant shows: it is a nonsense variant. Therefore, this criterion is not applied.
BP2
BP2 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP2 is: "Observed in trans with a pathogenic variant for dominant disorders or in cis with a pathogenic variant". The evidence for this variant shows: no such observations. Therefore, this criterion is not applied.
BP3
BP3 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP3 is: "In-frame deletions/insertions in a repetitive region without known function". The evidence for this variant shows: it is a nonsense change. Therefore, this criterion is not applied.
BP4
BP4 (Supporting)
According to standard ACMG guidelines, the rule for BP4 is: "Multiple lines of computational evidence suggest no impact". The evidence for this variant shows: in silico tools (CADD 8.59, SpliceAI 0.01, mixed predictions) do not support a deleterious effect on splicing or function. Therefore, this criterion is applied at Supporting strength because computational evidence suggests no impact.
BP5
BP5 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP5 is: "Variant found in a case with an alternate molecular basis for disease". The evidence for this variant shows: no such cases reported. Therefore, this criterion is not applied.
BP6
BP6 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP6 is: "Reputable source reports variant as benign, but without accessible evidence". The evidence for this variant shows: no such reports. Therefore, this criterion is not applied.
BP7
BP7 (Not Applied)
Strength Modified
According to standard ACMG guidelines, the rule for BP7 is: "Synonymous variant with no predicted impact on splicing". The evidence for this variant shows: it is not synonymous. Therefore, this criterion is not applied.