13-20189193-C-T

Position:

• chr13-20189193-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PS1_Moderate PM1 PM2 PM5 PP3_Strong

The NM_004004.6(GJB2):​c.389G>A​(p.Gly130Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,646 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 nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G130A) has been classified as Likely pathogenic.

• 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: 7.86

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 Pathogenic. Variant got 12 ACMG points.

• PS1: Transcript NM_004004.6 (GJB2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 5 uncertain in NM_004004.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr13-20189193-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 228264.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJB2	NM_004004.6	c.389G>A	p.Gly130Asp	missense_variant	2/2	ENST00000382848.5
GJB2	XM_011535049.3	c.389G>A	p.Gly130Asp	missense_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJB2	ENST00000382848.5	c.389G>A	p.Gly130Asp	missense_variant	2/2	1	NM_004004.6	P1
GJB2	ENST00000382844.2	c.389G>A	p.Gly130Asp	missense_variant	1/1			P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250566 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135536

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461646 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727124

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

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	0.86
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D;D;D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	.;.;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M;M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-6.8	D;D;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D;D;.
Sift4G	Pathogenic	0.0010	D;D;.
Polyphen		1.0	D;D;D
Vest4		0.98
MutPred		0.88		Gain of solvent accessibility (P = 0.008);Gain of solvent accessibility (P = 0.008);Gain of solvent accessibility (P = 0.008);
MVP		0.98
MPC		0.31
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.94
gMVP		0.96

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: rs779018464; hg19: chr13-20763332;