rs375599392

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_004004.6(GJB2):c.663G>C(p.Lys221Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000036 in 1,613,164 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K221T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

GJB2
NM_004004.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 0.496

Publications

3 publications found

Variant links:

Genes affected

GJB2 (HGNC:4284): (gap junction protein beta 2) This gene encodes a member of the gap junction protein family. The gap junctions were first characterized by electron microscopy as regionally specialized structures on plasma membranes of contacting adherent cells. These structures were shown to consist of cell-to-cell channels that facilitate the transfer of ions and small molecules between cells. The gap junction proteins, also known as connexins, purified from fractions of enriched gap junctions from different tissues differ. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Oct 2008]

GJB2 Gene-Disease associations (from GenCC):

Bart-Pumphrey syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
ichthyosis, hystrix-like, with hearing loss
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
keratoderma hereditarium mutilans
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P
palmoplantar keratoderma-deafness syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
autosomal recessive nonsyndromic hearing loss 1A
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, G2P, PanelApp Australia
hearing loss, autosomal recessive
Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
autosomal dominant keratitis-ichthyosis-hearing loss syndrome
Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
autosomal dominant nonsyndromic hearing loss 3A
Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
autosomal dominant nonsyndromic hearing loss
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
KID syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

GJB2 links:

ENSG00000296095 (HGNC:):

ENSG00000296095 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 111 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: -0.72044 (below the threshold of 3.09). Trascript score misZ: 0.4379 (below the threshold of 3.09). GenCC associations: The gene is linked to autosomal recessive nonsyndromic hearing loss 1A, ichthyosis, hystrix-like, with hearing loss, keratoderma hereditarium mutilans, hearing loss, autosomal recessive, Bart-Pumphrey syndrome, palmoplantar keratoderma-deafness syndrome, autosomal dominant keratitis-ichthyosis-hearing loss syndrome, autosomal dominant nonsyndromic hearing loss 3A, autosomal dominant nonsyndromic hearing loss, KID syndrome.

BP4

Computational evidence support a benign effect (MetaRNN=0.19724765).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6 link	c.663G>C	p.Lys221Asn	missense_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3 link	c.663G>C	p.Lys221Asn	missense_variant	Exon 2 of 2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
GJB2	ENST00000382848.5 link	c.663G>C	p.Lys221Asn	missense_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4
GJB2	ENST00000382844.2 link	c.663G>C	p.Lys221Asn	missense_variant	Exon 1 of 1	6		ENSP00000372295.1
ENSG00000296095	ENST00000736390.1 link	n.232-3339G>C		intron_variant	Intron 1 of 3

Frequencies

GnomAD3 genomes

AF:

0.0000328

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000403

AC:

AN:

248358

AF XY:

0.0000371

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000716

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000363

AC:

AN:

1460954

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

726786

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39692

South Asian (SAS)

AF:

0.00

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000450

AC:

AN:

1111918

Other (OTH)

AF:

0.0000331

AC:

AN:

60388

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74366

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41448

American (AMR)

AF:

0.0000654

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000588

AC:

AN:

68046

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.455

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000225

Hom.:

Bravo

AF:

0.0000340

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 1A

Uncertain:3

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

May 09, 2017

Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Nov 14, 2017

Counsyl

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

not provided

Uncertain:3

Feb 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 221 of the GJB2 protein (p.Lys221Asn). This variant is present in population databases (rs375599392, gnomAD 0.008%). This missense change has been observed in individual(s) with GJB2-related conditions (PMID: 25401782, 25555641). ClinVar contains an entry for this variant (Variation ID: 44764). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt GJB2 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Apr 18, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported in the heterozygous state without a second variant in patients with sensorineural hearing loss in the published literature (PMID: 34515852, 25401782); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 25388846, 25555641, 25401782, 34515852)

Jan 22, 2024

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity. (http://gnomad.broadinstitute.org) Computational tools predict that this variant is not damaging.

not specified

Uncertain:2

Apr 17, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The Lys221Asn varia nt in GJB2 has not been reported in the literature in any individuals with heari ng loss nor previously identified by our laboratory. However, this variant has b een identified in 0.01% (1/6984) of European American chromosomes in a broad pop ulation by the NHLBI Exome sequencing project (http://evs.gs.washington.edu/EVS/ ). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. Computational analyses (bioche mical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do no t provide strong support for or against an impact to the protein. In summary, th e clinical significance of this variant cannot be determined with certainty.

Apr 02, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GJB2 c.663G>C (p.Lys221Asn) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-05 in 248358 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in GJB2 causing Non-Syndromic Hearing Loss (4e-05 vs 0.00034), allowing no conclusion about variant significance. c.663G>C has been reported in the literature in individuals affected with Non-Syndromic Hearing Loss (Stanghellini_2014, Kashef_2015). These reports do not provide unequivocal conclusions about association of the variant with Non-Syndromic Hearing Loss. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25388846, 25401782, 25555641). ClinVar contains an entry for this variant (Variation ID: 44764). Based on the evidence outlined above, the variant was classified as uncertain significance.

Autosomal dominant keratitis-ichthyosis-hearing loss syndrome;C0265964:Mutilating keratoderma;C0266004:Knuckle pads, deafness AND leukonychia syndrome;C1835672:Palmoplantar keratoderma-deafness syndrome;C1844678:X-linked mixed hearing loss with perilymphatic gusher;C1865234:Ichthyosis, hystrix-like, with hearing loss;C2673759:Autosomal recessive nonsyndromic hearing loss 1A;C2675750:Autosomal dominant nonsyndromic hearing loss 3A

Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.084

BayesDel_noAF

Benign

-0.17

CADD

Benign

(source)

DANN

Benign

0.97

DEOGEN2

Benign

0.22

T;T;T

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.18

FATHMM_MKL

Uncertain

0.85

LIST_S2

Benign

0.0

.;.;T

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.20

T;T;T

MetaSVM

Uncertain

0.61

MutationAssessor

Benign

0.65

N;N;N

PhyloP100

0.50

PrimateAI

Benign

0.48

PROVEAN

Benign

-1.2

N;N;.

REVEL

Uncertain

0.31

Sift

Benign

0.18

T;T;.

Sift4G

Benign

0.14

T;T;.

Vest4

0.14

ClinPred

0.047

GERP RS

4.8

Varity_R

0.13

gMVP

0.64

Mutation Taster

=83/17

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over