rs765921870

Positions:

• chr13-20189317-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PP3_Strong PP5

The NM_004004.6(GJB2):​c.265C>T​(p.Leu89Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000684 in 1,461,738 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 6.80

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a helix (size 29) in uniprot entity CXB2_HUMAN there are 23 pathogenic changes around while only 1 benign (96%) in NM_004004.6
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.974
• PP5: Variant 13-20189317-G-A is Pathogenic according to our data. Variant chr13-20189317-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 437829.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJB2	NM_004004.6	c.265C>T	p.Leu89Phe	missense_variant	2/2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3	c.265C>T	p.Leu89Phe	missense_variant	2/2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5	c.265C>T	p.Leu89Phe	missense_variant	2/2	1	NM_004004.6	ENSP00000372299	P1
GJB2	ENST00000382844.2	c.265C>T	p.Leu89Phe	missense_variant	1/1			ENSP00000372295	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251270 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135816

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000131

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461738 Hom.: 0 Cov.: 33 AF XY: 0.0000110 AC XY: 8 AN XY: 727178

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000412 AC: 5

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Aug 01, 2024

GJB2: PM2, PM3, PM5, PP3 -

Nonsyndromic Deafness Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Molecular Genetics Laboratory, BC Children's and BC Women's Hospitals

Apr 28, 2017

To the best of our knowledge, this variant has not previously been reported in gene-specific databases or the literature; but has been seen at low frequency in individuals of South Asian ancestry reported in population databases (gnomAD, ExAC). In silico analyses all predict an impact on the protein. The amino acid immediately adjacent to this variant is also a leucine; as reported extensively in the literature, mutation of this amnio acid to proline (p.Leu90Pro) is pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D;D;D
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.95	.;.;D
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M;M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-3.3	D;D;.
REVEL	Pathogenic	0.85
Sift	Uncertain	0.022	D;D;.
Sift4G	Uncertain	0.018	D;D;.
Polyphen		1.0	D;D;D
Vest4		0.79
MutPred		0.83		Gain of glycosylation at T86 (P = 0.1025);Gain of glycosylation at T86 (P = 0.1025);Gain of glycosylation at T86 (P = 0.1025);
MVP		0.97
MPC		0.27
ClinPred		0.92	D
GERP RS		5.3
Varity_R		0.78
gMVP		0.93

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

LitVar

Other links and lift over

dbSNP: rs765921870; hg19: chr13-20763456;