rs374680617

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PP2PP3_ModerateBS1_Supporting

The NM_005267.5(GJA8):​c.487G>A​(p.Val163Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,890 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 Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

GJA8
NM_005267.5 missense

Scores

10
7
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.02

Publications

0 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: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a disulfide_bond (size 140) in uniprot entity CXA8_HUMAN there are 31 pathogenic changes around while only 3 benign (91%) in NM_005267.5
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, 0.924
BS1
Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.00000479 (7/1461890) while in subpopulation AMR AF = 0.000157 (7/44724). AF 95% confidence interval is 0.0000728. There are 0 homozygotes in GnomAdExome4. There are 1 alleles in the male GnomAdExome4 subpopulation. Median coverage is 35. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GJA8NM_005267.5 linkc.487G>A p.Val163Met missense_variant Exon 2 of 2 ENST00000369235.2 NP_005258.2 P48165X5D7G1
GJA8XM_011509417.3 linkc.487G>A p.Val163Met 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.487G>A p.Val163Met missense_variant Exon 2 of 2 6 NM_005267.5 ENSP00000358238.1 P48165

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251422
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461890
Hom.:
0
Cov.:
35
AF XY:
0.00000138
AC XY:
1
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000157
AC:
7
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:
0.00
AC:
0
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
1
2
3
4
5
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
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Cataract 1 multiple types Uncertain:1
Aug 08, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, this variant is a rare missense change with uncertain impact on protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This sequence change replaces valine with methionine at codon 163 of the GJA8 protein (p.Val163Met). The valine residue is highly conserved and there is a small physicochemical difference between valine and methionine. This variant is present in population databases (rs374680617, ExAC 0.01%) but has not been reported in the literature in individuals with a GJA8-related disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.21
BayesDel_addAF
Pathogenic
0.31
D
BayesDel_noAF
Pathogenic
0.44
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.95
D
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.93
D
M_CAP
Pathogenic
0.48
D
MetaRNN
Pathogenic
0.92
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.9
M
PhyloP100
8.0
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-2.8
D
REVEL
Pathogenic
0.93
Sift
Uncertain
0.0010
D
Sift4G
Pathogenic
0.0010
D
Polyphen
1.0
D
Vest4
0.79
MVP
0.93
ClinPred
0.94
D
GERP RS
4.9
Varity_R
0.73
gMVP
0.90
Mutation Taster
=55/45
polymorphism

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: rs374680617; hg19: chr1-147380569; API