rs80358205

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP2PP3_StrongPP5

The NM_005267.5(GJA8):​c.593G>A​(p.Arg198Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R198W) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

GJA8
NM_005267.5 missense

Scores

15
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:1

Conservation

PhyloP100: 9.84

Publications

24 publications found
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 Gene-Disease associations (from GenCC):
  • cataract 1 multiple types
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • cataract - microcornea syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • early-onset nuclear cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • early-onset sutural cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • pulverulent cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • total early-onset cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_005267.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-147908547-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2581012.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 49 curated pathogenic missense variants (we use a threshold of 10). The gene has 13 curated benign missense variants. Trascript score misZ: -0.35816 (below the threshold of 3.09). GenCC associations: The gene is linked to cataract 1 multiple types, cataract - microcornea syndrome, early-onset nuclear cataract, early-onset sutural cataract, pulverulent cataract, total early-onset cataract.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993
PP5
Variant 1-147908548-G-A is Pathogenic according to our data. Variant chr1-147908548-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 8726.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GJA8NM_005267.5 linkc.593G>A p.Arg198Gln missense_variant Exon 2 of 2 ENST00000369235.2 NP_005258.2
GJA8XM_011509417.3 linkc.593G>A p.Arg198Gln missense_variant Exon 1 of 2 XP_011507719.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GJA8ENST00000369235.2 linkc.593G>A p.Arg198Gln missense_variant Exon 2 of 2 6 NM_005267.5 ENSP00000358238.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461894
Hom.:
0
Cov.:
35
AF XY:
0.00
AC XY:
0
AN XY:
727248
show subpopulations
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:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cataract 1 multiple types Pathogenic:3Uncertain:1
Mar 23, 2006
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Oct 06, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 8726). This missense change has been observed in individual(s) with autosomal dominant congenital cataracts (PMID: 16604058, 24281366; Invitae). In at least one individual the variant was observed to be de novo. It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 198 of the GJA8 protein (p.Arg198Gln).

Jan 21, 2023
Dept. Genetics and Cancer, Menzies Institute for Medical Research, University of Tasmania
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

Variant identified and curated during a GJA8 specific review of the literature in relation to pediatric or congenital cataract. ACMG-AMP criteria applied: PP1(Moderate), PS4(Supporting), PM2(Supporting), PP3. Original variant report: PMID:16254549;24281366. The cataract phenotype/s reported for this variant are: Nuclear, and Posterior subcapsular. Additional phenotype/s reported in these individual/s are: Microphthalmia. Gene review and curation guidelines are outlined in: https://doi.org/10.1080/17469899.2023.2160320

Mar 30, 2012
Eye Genetics Research Group, Children's Medical Research Institute
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research

not provided Pathogenic:1
Mar 26, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 36736424, 25003127, 21091421, 26659599, 20086076, 28569743, 26986070, Bai2022[casereport], 16604058, 24281366, KONG2022[casereport], 33800913)

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.98
D
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.84
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D
M_CAP
Pathogenic
0.76
D
MetaRNN
Pathogenic
0.99
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.4
M
PhyloP100
9.8
PrimateAI
Uncertain
0.71
T
PROVEAN
Uncertain
-3.7
D
REVEL
Pathogenic
0.97
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.0050
D
Vest4
1.0
ClinPred
1.0
D
GERP RS
4.9
Varity_R
0.90
gMVP
0.96
Mutation Taster
=6/94
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

Publications

Other links and lift over

dbSNP: rs80358205; hg19: chr1-147380675; API