The ClinGen Evidence Repository is an FDA-recognized human genetic variant database containing expert-curated assertions regarding variants' pathogenicity and supporting evidence summaries. [Disclaimer]


Variant: NM_004004.6(GJB2):c.677T>G (p.Val226Gly)

CA6904209

447450 (ClinVar)

Gene: GJB2
Condition: nonsyndromic genetic deafness
Inheritance Mode: Autosomal recessive inheritance
UUID: 2b5171d0-5733-4e05-a77e-5d32d43be312

HGVS expressions

NM_004004.6:c.677T>G
NM_004004.6(GJB2):c.677T>G (p.Val226Gly)
NC_000013.11:g.20188905A>C
CM000675.2:g.20188905A>C
NC_000013.10:g.20763044A>C
CM000675.1:g.20763044A>C
NC_000013.9:g.19661044A>C
NG_008358.1:g.9071T>G
ENST00000382844.2:c.677T>G
ENST00000382848.5:c.677T>G
ENST00000382844.1:c.677T>G
ENST00000382848.4:c.677T>G
NM_004004.5:c.677T>G

Uncertain Significance

Met criteria codes 1
PM2
Not Met criteria codes 25
BP2 BP3 BP1 BP4 BP5 BP7 BA1 PS4 PS2 PS3 PS1 PM3 PM1 PM4 PM5 PM6 PP1 PP4 PP2 PP3 PVS1 BS2 BS4 BS3 BS1

Evidence Links 0

Expert Panel

Criteria Specification Information

Criteria Specification: 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

Criteria Specification Approval History
Criteria Specifications for this VCEP
Evidence submitted by expert panel
Hearing Loss VCEP
The c.677T>G variant in GJB2 is a missense variant predicted to cause substitution of valine to glycine at amino acid 226. The highest population minor allele frequency in gnomAD v2.1.1 is 0.003% (1/35370) in Latino/Admixed American chromosomes, which is below the PM2_Supporting thresholds defined by the ClinGen Hearing Loss Expert Panel (≤0.007%) for autosomal recessive disorders (PM2_Supporting). The computational predictor REVEL gives a score of 0.586 which is neither above nor below the thresholds predicting a damaging or benign impact on USH2A function (no criteria met). It has been reported in the literature in one heterozygous individual with hearing loss; however, a second variant was not identified and there was no reported family history of hearing loss (no criteria met; PMID: 17666888). This variant has been reported by several clinical laboratories in ClinVar as a variant of uncertain significance (ClinVar Variation ID: 447450). Internal laboratory evidence indicates that the variant has been identified in at least three individuals with hearing loss in the heterozygous state without a second GJB2 variant. One individual was reported to have multiple affected relatives; however, segregation data was not available (no criteria met; SCV000613524.1, SCV000731317.1, SCV002817016.1, SCV002179797.2). In summary, this variant is classified as a variant of uncertain significance based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP; PM2_Supporting. The ClinGen Hearing Loss VCEP Specifications Version 2; 09/26/2023.
Met criteria codes
PM2
This allele is present in 0.003% of Latino alleles which is below the PM2 cutoff of 0.007% for recessive hearing loss.
Not Met criteria codes
BP2
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BP3
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BP1
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BP4
The REVEL score of 0.586 falls in between what is predicted to be pathogenic/benign.
BP5
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BP7
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BA1
This allele is present in 0.003% of Latino alleles which is below the PM2 cutoff of 0.007% for recessive hearing loss.
PS4
There are 2 het cases (one with breast or ovarian cancer and one with HL). No mention of HL status in cancer patient.
PS2
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PS3
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PS1
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PM3
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PM1
HLWG only uses this rule for the pore domain of KCNQ4
PM4
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PM5
The p.Val226Asp variant is a VUS in ClinVar.
PM6
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PP1
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PP4
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PP2
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
PP3
The REVEL score of 0.586 falls in between what is predicted to be pathogenic/benign.
PVS1
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BS2
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BS4
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BS3
No code specific comments provided, please refer to the summary above or general recommendations provided in the guideline
BS1
This allele is present in 0.003% of Latino alleles which is below the PM2 cutoff of 0.007% for recessive hearing loss.
Approved on: 2023-09-26
Published on: 2023-10-05
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