rs1555341850

chr13-20189070-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_004004.6(GJB2):c.512C>T(p.Ala171Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,942 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. A171T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GJB2 NM_004004.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.36

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 Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_004004.6
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19865248).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJB2	NM_004004.6	c.512C>T	p.Ala171Val	missense_variant	2/2	ENST00000382848.5
GJB2	XM_011535049.3	c.512C>T	p.Ala171Val	missense_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJB2	ENST00000382848.5	c.512C>T	p.Ala171Val	missense_variant	2/2	1	NM_004004.6	P1
GJB2	ENST00000382844.2	c.512C>T	p.Ala171Val	missense_variant	1/1			P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152180 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461762 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727168

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152180 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74368

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Mar 22, 2017

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 29, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
Cadd	Benign	17
Dann	Benign	0.96
DEOGEN2	Uncertain	0.51	D;D;D
Eigen	Benign	-0.63
Eigen_PC	Benign	-0.58
FATHMM_MKL	Benign	0.37	N
M_CAP	Benign	0.062	D
MetaRNN	Benign	0.20	T;T;T
MetaSVM	Uncertain	-0.14	T
MutationAssessor	Benign	0.71	N;N;N
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	0.12	N;N;.
REVEL	Uncertain	0.45
Sift	Benign	0.36	T;T;.
Sift4G	Benign	0.37	T;T;.
Polyphen		0.039	B;B;B
Vest4		0.16
MutPred		0.48		Gain of ubiquitination at K168 (P = 0.2404);Gain of ubiquitination at K168 (P = 0.2404);Gain of ubiquitination at K168 (P = 0.2404);
MVP		0.76
MPC		0.039
ClinPred		0.25	T
GERP RS		4.8
Varity_R		0.27
gMVP		0.76

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: rs1555341850; hg19: chr13-20763209;