rs121434643

Positions:

• chr1-147908094-G-A
• chr1-147908094-G-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_005267.5(GJA8):​c.139G>A​(p.Asp47Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D47H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJA8 NM_005267.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.92

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 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 chr1-147908094-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 280147.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 1-147908094-G-A is Pathogenic according to our data. Variant chr1-147908094-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 8727.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-147908094-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJA8	NM_005267.5	c.139G>A	p.Asp47Asn	missense_variant	2/2	ENST00000369235.2	NP_005258.2
GJA8	XM_011509417.3	c.139G>A	p.Asp47Asn	missense_variant	1/2		XP_011507719.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJA8	ENST00000369235.2	c.139G>A	p.Asp47Asn	missense_variant	2/2	6	NM_005267.5	ENSP00000358238.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Cataract 1 multiple types Pathogenic:2

Pathogenic, criteria provided, single submitter	curation	Dept. Genetics and Cancer, Menzies Institute for Medical Research, University of Tasmania	Jan 21, 2023	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), PS4(Moderate), PM1(Supporting), PM2(Supporting), PM5(Supporting), PP3. Original variant report: PMID:18006672;21174522;21921990;26004348;30262699;28544770;28526010. The cataract phenotype/s reported for this variant are: Nuclear, Pulverulent nuclear, Nuclear with punctiform opacities, Zonular, and Perinuclear. Gene review and curation guidelines are outlined in: https://doi.org/10.1080/17469899.2023.2160320 -
Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 01, 2011	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	3.3	M
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-5.0	D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.95		Gain of catalytic residue at D47 (P = 0.1938);
MVP		0.96
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.84
gMVP		0.98

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

LitVar

Other links and lift over

dbSNP: rs121434643; hg19: chr1-147380221;