6-121446900-C-A

Variant names:

• chr6-121446900-C-A
• rs1773898086
• NM_000165.5:c.53C>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000165.5(GJA1):​c.53C>A​(p.Ser18*) variant causes a stop gained 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. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJA1 NM_000165.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.91

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 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 40 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-121446900-C-A is Pathogenic according to our data. Variant chr6-121446900-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 941060.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.53C>A	p.Ser18*	stop_gained	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.53C>A	p.Ser18*	stop_gained	Exon 2 of 2	1	NM_000165.5	ENSP00000282561.3
GJA1	ENST00000647564.1	c.53C>A	p.Ser18*	stop_gained	Exon 2 of 2			ENSP00000497565.1
GJA1	ENST00000649003.1	c.53C>A	p.Ser18*	stop_gained	Exon 2 of 2			ENSP00000497283.1
GJA1	ENST00000650427.1	c.53C>A	p.Ser18*	stop_gained	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

Dec 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ser18*) in the GJA1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 365 amino acid(s) of the GJA1 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of autosomal recessive oculodentodigital dysplasia (internal data). ClinVar contains an entry for this variant (Variation ID: 941060). This variant disrupts a region of the GJA1 protein in which other variant(s) (p.Arg33*) have been determined to be pathogenic (PMID: 16816024, 23606748). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.84
GERP RS		6.2

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: rs1773898086; hg19: chr6-121768046;