rs1555341937

Variant names:

• chr13-20189278-TCTC-T
• rs1555341937
• NM_004004.6:c.301_303delGAG

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_004004.6(GJB2):​c.301_303delGAG​(p.Glu101del) variant causes a conservative inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,602 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (no stars). Synonymous variant affecting the same amino acid position (i.e. E101E) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GJB2 NM_004004.6 conservative_inframe_deletion
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 2.48
• Publications: 0 publications found

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]

GJB2 Gene-Disease associations (from GenCC):

• Bart-Pumphrey syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
• ichthyosis, hystrix-like, with hearing loss

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp
• keratoderma hereditarium mutilans

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P
• palmoplantar keratoderma-deafness syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
• autosomal recessive nonsyndromic hearing loss 1A

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, G2P, PanelApp Australia
• hearing loss, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• autosomal dominant keratitis-ichthyosis-hearing loss syndrome

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
• autosomal dominant nonsyndromic hearing loss 3A

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• KID syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000296095 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in NM_004004.6
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_004004.6. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJB2	NM_004004.6	c.301_303delGAG	p.Glu101del	conservative_inframe_deletion	Exon 2 of 2	ENST00000382848.5	NP_003995.2
GJB2	XM_011535049.3	c.301_303delGAG	p.Glu101del	conservative_inframe_deletion	Exon 2 of 2		XP_011533351.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJB2	ENST00000382848.5	c.301_303delGAG	p.Glu101del	conservative_inframe_deletion	Exon 2 of 2	1	NM_004004.6	ENSP00000372299.4
GJB2	ENST00000382844.2	c.301_303delGAG	p.Glu101del	conservative_inframe_deletion	Exon 1 of 1	6		ENSP00000372295.1
ENSG00000296095	ENST00000736390.1	n.232-3701_232-3699delGAG		intron_variant	Intron 1 of 3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461602 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727096

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53134

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Autosomal recessive nonsyndromic hearing loss 1A Uncertain:1

Jan 24, 2018

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.5
Mutation Taster		=52/48	polymorphism

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

Other links and lift over

dbSNP: rs1555341937; hg19: chr13-20763417;