rs398122937

Variant names:

• chr13-20142862-C-T
• rs398122937
• NM_021954.4:c.427G>A

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_021954.4(GJA3):​c.427G>A​(p.Gly143Arg) 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. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G143E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GJA3 NM_021954.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.74
• Publications: 21 publications found

Genes affected

GJA3 (HGNC:4277): (gap junction protein alpha 3) The protein encoded by this gene is a connexin and is a component of lens fiber gap junctions. Defects in this gene are a cause of zonular pulverulent cataract type 3 (CZP3). [provided by RefSeq, Jan 2010]

GJA3 Gene-Disease associations (from GenCC):

• cataract 14 multiple types

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• early-onset nuclear cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset posterior polar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pulverulent cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000299362 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 15 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 1.7112 (below the threshold of 3.09). Trascript score misZ: -0.026578 (below the threshold of 3.09). GenCC associations: The gene is linked to early-onset nuclear cataract, pulverulent cataract, early-onset posterior polar cataract, cataract 14 multiple types.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.942
• PP5: Variant 13-20142862-C-T is Pathogenic according to our data. Variant chr13-20142862-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 50945.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJA3	NM_021954.4	c.427G>A	p.Gly143Arg	missense_variant	Exon 2 of 2	ENST00000241125.4	NP_068773.2
GJA3	XM_011535048.3	c.427G>A	p.Gly143Arg	missense_variant	Exon 2 of 2		XP_011533350.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJA3	ENST00000241125.4	c.427G>A	p.Gly143Arg	missense_variant	Exon 2 of 2	3	NM_021954.4	ENSP00000241125.3
ENSG00000299362	ENST00000762843.1	n.133+4860C>T		intron_variant	Intron 1 of 1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cataract 14 multiple types Pathogenic:3

May 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 143 of the GJA3 protein (p.Gly143Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal dominant congenital cataract (PMID: 22876138). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 50945). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GJA3 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects GJA3 function (PMID: 24019978). For these reasons, this variant has been classified as Pathogenic. -

Jan 21, 2023

Dept. Genetics and Cancer, Menzies Institute for Medical Research, University of Tasmania

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

Variant identified and curated during a GJA3 specific review of the literature in relation to pediatric or congenital cataract. ACMG-AMP criteria applied: PP1(Strong), PS4(Supporting), PM2(Supporting), PP3. Original variant report: PMID:22876138;34169787. The cataract phenotype reported for this variant is: Pulverulent disk-like (Coppock). Gene review and curation guidelines are outlined in: https://doi.org/10.1080/17469899.2023.2160320 -

Jan 01, 2012

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		7.7
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.4	D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0020	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.65		Gain of MoRF binding (P = 0.0255);
MVP		0.86
MPC		2.2
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.80
gMVP		0.98
Mutation Taster		=2/98	disease causing (ClinVar)

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: rs398122937; hg19: chr13-20717001;