rs765172751

chr13-20188995-A-Cchr13-20188995-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_004004.6(GJB2):c.587T>G(p.Ile196Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I196T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.41

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 6 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_004004.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.844

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJB2	NM_004004.6	c.587T>G	p.Ile196Ser	missense_variant	2/2	ENST00000382848.5
GJB2	XM_011535049.3	c.587T>G	p.Ile196Ser	missense_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJB2	ENST00000382848.5	c.587T>G	p.Ile196Ser	missense_variant	2/2	1	NM_004004.6	P1
GJB2	ENST00000382844.2	c.587T>G	p.Ile196Ser	missense_variant	1/1			P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251346 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135864

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461682 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727148

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	0.050
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	D;D;D
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.84	D;D;D
MetaSVM	Uncertain	0.75	D
MutationAssessor	Uncertain	2.2	M;M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Pathogenic	-4.4	D;D;.
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0090	D;D;.
Sift4G	Uncertain	0.021	D;D;.
Polyphen		0.95	P;P;P
Vest4		0.47
MutPred		0.47		Gain of catalytic residue at I196 (P = 0.0094);Gain of catalytic residue at I196 (P = 0.0094);Gain of catalytic residue at I196 (P = 0.0094);
MVP		0.88
MPC		0.19
ClinPred		0.99	D
GERP RS		4.5
Varity_R		0.65
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: rs765172751; hg19: chr13-20763134;