chrX-71223217-C-G

Position:

• chrX-71223217-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000646835.1(GJB1):​c.-132-3C>G variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: GJB1 ENST00000646835.1 splice_region, splice_polypyrimidine_tract, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.11

Genes affected

GJB1 (HGNC:4283): (gap junction protein beta 1) This gene encodes a member of the gap junction protein family. The gap junction proteins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and small molecules between cells. 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 cause X-linked Charcot-Marie-Tooth disease, an inherited peripheral neuropathy. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJB1	NM_001097642.3	c.-16-475C>G		intron_variant			NP_001091111.1
GJB1	XM_011530907.3	c.-17+451C>G		intron_variant			XP_011529209.1
GJB1	NM_000166.6			upstream_gene_variant		ENST00000361726.7	NP_000157.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJB1	ENST00000361726.7			upstream_gene_variant		1	NM_000166.6	ENSP00000354900	P1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease X-linked dominant 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Institute for Human Genetics and Genomic Medicine, Uniklinik RWTH Aachen

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	22
DANN	Benign	0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs2092540944; hg19: chrX-70443067;