1-147907977-G-A

Position:

chr1-147907977-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PP3_ModerateBS1_Supporting

The NM_005267.5(GJA8):c.22G>A(p.Gly8Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

GJA8
NM_005267.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.92

Variant links:

Genes affected

GJA8 (HGNC:4281): (gap junction protein alpha 8) This gene encodes a transmembrane connexin protein that is necessary for lens growth and maturation of lens fiber cells. The encoded protein is a component of gap junction channels and functions in a calcium and pH-dependent manner. Mutations in this gene have been associated with zonular pulverulent cataracts, nuclear progressive cataracts, and cataract-microcornea syndrome. [provided by RefSeq, Dec 2009]

GJA8 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.919

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0000591 (9/152250) while in subpopulation AFR AF= 0.000217 (9/41544). AF 95% confidence interval is 0.000112. There are 0 homozygotes in gnomad4. There are 4 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJA8	NM_005267.5 linkuse as main transcript	c.22G>A	p.Gly8Arg	missense_variant	2/2	ENST00000369235.2	NP_005258.2	P48165X5D7G1
GJA8	XM_011509417.3 linkuse as main transcript	c.22G>A	p.Gly8Arg	missense_variant	1/2		XP_011507719.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJA8	ENST00000369235.2 linkuse as main transcript	c.22G>A	p.Gly8Arg	missense_variant	2/2	6	NM_005267.5	ENSP00000358238.1		P48165

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

251414

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135892

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000980

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000226

AC:

AN:

1461704

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727176

show subpopulations

Gnomad4 AFR exome

AF:

0.000687

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000696

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74438

show subpopulations

Gnomad4 AFR

AF:

0.000217

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000658

Hom.:

Bravo

AF:

0.0000378

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 01, 2022

The c.22G>A (p.G8R) alteration is located in exon 2 (coding exon 1) of the GJA8 gene. This alteration results from a G to A substitution at nucleotide position 22, causing the glycine (G) at amino acid position 8 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cataract 1 multiple types

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 13, 2023

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 8 of the GJA8 protein (p.Gly8Arg). This variant is present in population databases (rs202041458, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GJA8-related conditions. ClinVar contains an entry for this variant (Variation ID: 2342241). 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 GJA8 protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.95

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.48

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.93

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.67

MetaRNN

Pathogenic

0.92

MetaSVM

Pathogenic

1.1

MutationAssessor

Benign

1.7

PrimateAI

Pathogenic

0.95

PROVEAN

Pathogenic

-6.9

REVEL

Pathogenic

0.89

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.89

MutPred

0.67

Gain of solvent accessibility (P = 0.1319);

MVP

0.96

ClinPred

0.70

GERP RS

5.2

Varity_R

0.92

gMVP

0.98

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over