chr2-208128296-G-T

Variant names:

• chr2-208128296-G-T
• NM_020989.4:c.432C>A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_020989.4(CRYGC):​c.432C>A​(p.Tyr144*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CRYGC NM_020989.4 stop_gained
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 0.403

Genes affected

CRYGC (HGNC:2410): (crystallin gamma C) This gene encodes a member of the beta/gamma-crystallin family of proteins. Crystallins constitute the major proteins of vertebrate eye lens and maintain the transparency and refractive index of the lens. This gene and several family members are present in a gene cluster on chromosome 2. Mutations in this gene have been shown to cause multiple types of cataract, including Coppock-like cataract and zonular pulverulent cataract, among others. [provided by RefSeq, Jan 2015]

LOC100507443 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.177 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-208128296-G-T is Pathogenic according to our data. Variant chr2-208128296-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3061306.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYGC	NM_020989.4	c.432C>A	p.Tyr144*	stop_gained	Exon 3 of 3	ENST00000282141.4	NP_066269.1
LOC100507443	NR_038437.1	n.98-8760G>T		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYGC	ENST00000282141.4	c.432C>A	p.Tyr144*	stop_gained	Exon 3 of 3	1	NM_020989.4	ENSP00000282141.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

CRYGC-related disorder Pathogenic:1

Feb 27, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CRYGC c.432C>A variant is predicted to result in premature protein termination (p.Tyr144*). To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Of note, a different nucleotide change (c.432C>G) leading to the same nonsense variant (p.Tyr144*) has been reported in patients with cataracts (Family C in Sun et al. 2017. PubMed ID: 29386872; Case 2 in Taylan Sekeroglu et al. 2020. PubMed ID: 33510601). Nonsense variants in CRYGC are expected to be pathogenic. The c.432C>A (p.Tyr144*) variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Uncertain	0.40
Eigen_PC	Benign	0.19
FATHMM_MKL	Uncertain	0.93	D
Vest4		0.73
GERP RS		1.2

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-208993020;