13-20189071-C-G

Variant names:

• chr13-20189071-C-G
• NM_004004.6:c.511G>C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_004004.6(GJB2):​c.511G>C​(p.Ala171Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,756 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A171T) has been classified as Likely benign.

• 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: 0.559

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 4 ACMG points.

• PM1: In a chain Gap junction beta-2 protein (size 225) in uniprot entity CXB2_HUMAN there are 70 pathogenic changes around while only 16 benign (81%) in NM_004004.6
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6	c.511G>C	p.Ala171Pro	missense_variant	Exon 2 of 2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3	c.511G>C	p.Ala171Pro	missense_variant	Exon 2 of 2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5	c.511G>C	p.Ala171Pro	missense_variant	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4
GJB2	ENST00000382844.2	c.511G>C	p.Ala171Pro	missense_variant	Exon 1 of 1	6		ENSP00000372295.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461756 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727162

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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.75	D;D;D
Eigen	Benign	-0.048
Eigen_PC	Benign	-0.24
FATHMM_MKL	Benign	0.27	N
LIST_S2	Uncertain	0.94	.;.;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.58	D;D;D
MetaSVM	Uncertain	0.40	D
MutationAssessor	Uncertain	2.7	M;M;M
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-1.7	N;N;.
REVEL	Uncertain	0.57
Sift	Benign	0.27	T;T;.
Sift4G	Benign	0.16	T;T;.
Polyphen		0.98	D;D;D
Vest4		0.48
MutPred		0.51		Loss of catalytic residue at A171 (P = 0.0432);Loss of catalytic residue at A171 (P = 0.0432);Loss of catalytic residue at A171 (P = 0.0432);
MVP		0.91
MPC		0.28
ClinPred		0.52	D
GERP RS		2.9
Varity_R		0.83
gMVP		0.90

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr13-20763210;