1-147908023-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PP2PP3_StrongPP5_Moderate

The NM_005267.5(GJA8):c.68G>C(p.Arg23Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,804 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R23G) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GJA8
NM_005267.5 missense

Scores

Clinical Significance

Likely pathogenic criteria provided, single submitter P:2

Conservation

PhyloP100: 8.11

Publications

29 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

GJA8 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_005267.5

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 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, 0.995

PP5

Variant 1-147908023-G-C is Pathogenic according to our data. Variant chr1-147908023-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 8724.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GJA8	NM_005267.5 link	c.68G>C	p.Arg23Thr	missense_variant	Exon 2 of 2	ENST00000369235.2	NP_005258.2
GJA8	XM_011509417.3 link	c.68G>C	p.Arg23Thr	missense_variant	Exon 1 of 2		XP_011507719.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GJA8	ENST00000369235.2 link	c.68G>C	p.Arg23Thr	missense_variant	Exon 2 of 2	6	NM_005267.5	ENSP00000358238.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461804

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727198

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111940

Other (OTH)

AF:

0.00

AC:

AN:

60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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.:

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cataract 1 multiple types

Pathogenic:2

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 GJA8 specific review of the literature in relation to pediatric or congenital cataract. ACMG-AMP criteria applied: PP1(Strong), PM1(Supporting), PM2(Supporting), PP3. Original variant report: PMID:14627691. The cataract phenotype reported for this variant is: Nuclear. Gene review and curation guidelines are outlined in: https://doi.org/10.1080/17469899.2023.2160320 -

Nov 01, 2003

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

0.95

BayesDel_addAF

Pathogenic

0.53

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

(source)

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.97

Eigen

Pathogenic

0.76

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.94

M_CAP

Pathogenic

0.90

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.5

PhyloP100

8.1

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-3.5

REVEL

Pathogenic

0.94

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.97

MutPred

0.96

Loss of MoRF binding (P = 0.0424);

MVP

0.95

ClinPred

0.99

GERP RS

5.0

Varity_R

0.90

gMVP

0.98

Mutation Taster

=3/97

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over