NM_005267.5:c.97C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PP2PP3_Strong

The NM_005267.5(GJA8):​c.97C>T​(p.Arg33Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000155 in 1,614,092 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R33G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

GJA8
NM_005267.5 missense

Scores

16
2
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.06

Publications

1 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: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain 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, 0.98

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GJA8NM_005267.5 linkc.97C>T p.Arg33Trp missense_variant Exon 2 of 2 ENST00000369235.2 NP_005258.2 P48165X5D7G1
GJA8XM_011509417.3 linkc.97C>T p.Arg33Trp 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.97C>T p.Arg33Trp missense_variant Exon 2 of 2 6 NM_005267.5 ENSP00000358238.1 P48165

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152196
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
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
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251468
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000164
AC:
24
AN:
1461778
Hom.:
0
Cov.:
35
AF XY:
0.00000963
AC XY:
7
AN XY:
727206
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
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:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000198
AC:
22
AN:
1111918
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.527
Heterozygous variant carriers
0
2
3
5
6
8
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
AF:
0.00000657
AC:
1
AN:
152314
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74480
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41574
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
ExAC
AF:
0.00000824
AC:
1
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is present in population databases (rs587710840, ExAC 0.01%) but has not been reported in the literature in individuals with a GJA8-related disease. This sequence change replaces arginine with tryptophan at codon 33 of the GJA8 protein (p.Arg33Trp). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and tryptophan. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.92
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.53
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.98
D
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.58
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Pathogenic
0.99
D
M_CAP
Pathogenic
0.90
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Pathogenic
0.97
D
MutationAssessor
Pathogenic
3.7
H
PhyloP100
4.1
PrimateAI
Pathogenic
0.88
D
PROVEAN
Pathogenic
-7.9
D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.95
MutPred
0.84
Loss of MoRF binding (P = 0.0748);
MVP
0.96
ClinPred
1.0
D
GERP RS
4.0
Varity_R
0.94
gMVP
0.99
Mutation Taster
=12/88
disease causing

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: rs587710840; hg19: chr1-147380179; COSMIC: COSV53787626; API