chr6-121446911-G-A

Variant names:

• chr6-121446911-G-A
• rs1773898234
• NM_000165.5:c.64G>A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Moderate

The NM_000165.5(GJA1):​c.64G>A​(p.Gly22Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJA1 NM_000165.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 10.0

Genes affected

GJA1 (HGNC:4274): (gap junction protein alpha 1) This gene is a member of the connexin gene family. The encoded protein is a component of gap junctions, which are composed of arrays of intercellular channels that provide a route for the diffusion of low molecular weight materials from cell to cell. The encoded protein is the major protein of gap junctions in the heart that are thought to have a crucial role in the synchronized contraction of the heart and in embryonic development. A related intronless pseudogene has been mapped to chromosome 5. Mutations in this gene have been associated with oculodentodigital dysplasia, autosomal recessive craniometaphyseal dysplasia and heart malformations. [provided by RefSeq, May 2014]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a helix (size 17) in uniprot entity CXA1_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000165.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the GJA1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 41 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 1.2784 (below the threshold of 3.09). Trascript score misZ: 3.3775 (above the threshold of 3.09). GenCC associations: The gene is linked to craniometaphyseal dysplasia, autosomal recessive, Hallermann-Streiff syndrome, syndactyly type 3, oculodentodigital dysplasia, nonsyndromic genetic hearing loss, hypoplastic left heart syndrome 1, autosomal dominant palmoplantar keratoderma and congenital alopecia, oculodentodigital dysplasia, autosomal recessive, craniometaphyseal dysplasia, erythrokeratodermia variabilis et progressiva 3, erythrokeratodermia variabilis.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 6-121446911-G-A is Pathogenic according to our data. Variant chr6-121446911-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 844190.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJA1	NM_000165.5	c.64G>A	p.Gly22Arg	missense_variant	Exon 2 of 2	ENST00000282561.4	NP_000156.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJA1	ENST00000282561.4	c.64G>A	p.Gly22Arg	missense_variant	Exon 2 of 2	1	NM_000165.5	ENSP00000282561.3
GJA1	ENST00000647564.1	c.64G>A	p.Gly22Arg	missense_variant	Exon 2 of 2			ENSP00000497565.1
GJA1	ENST00000649003.1	c.64G>A	p.Gly22Arg	missense_variant	Exon 2 of 2			ENSP00000497283.1
GJA1	ENST00000650427.1	c.64G>A	p.Gly22Arg	missense_variant	Exon 2 of 2			ENSP00000497367.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Oculodentodigital dysplasia, autosomal recessive Pathogenic:1

Apr 26, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine with arginine at codon 22 of the GJA1 protein (p.Gly22Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. This variant disrupts the p.Gly22 amino acid residue in GJA1. Other variant(s) that disrupt this residue have been observed in individuals with GJA1-related conditions (PMID: 12457340), which suggests that this may be a clinically significant amino acid residue. This variant is not present in population databases (ExAC no frequency). This variant has been observed to be de novo in an individual affected with oculodentodigital dysplasia (ODDD) (Invitae), and this variant has been reported in an unrelated individual with this condition (PMID: 19338053). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	D;D;D;D;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	.;.;.;.;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	H;H;H;H;H
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-6.8	.;.;D;.;.
REVEL	Pathogenic	0.97
Sift	Uncertain	0.014	.;.;D;.;.
Sift4G	Pathogenic	0.0	.;.;D;.;.
Polyphen		1.0	D;D;D;D;D
Vest4		0.99
MutPred		0.97		Gain of MoRF binding (P = 0.0089);Gain of MoRF binding (P = 0.0089);Gain of MoRF binding (P = 0.0089);Gain of MoRF binding (P = 0.0089);Gain of MoRF binding (P = 0.0089);
MVP		0.99
MPC		1.5
ClinPred		1.0	D
GERP RS		6.2
Varity_R		0.96
gMVP		1.0

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: rs1773898234; hg19: chr6-121768057;