3-186538881-T-C

Position:

• chr3-186538881-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_017541.4(CRYGS):​c.352A>G​(p.Ile118Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CRYGS NM_017541.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.505

Genes affected

CRYGS (HGNC:2417): (crystallin gamma S) Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Gamma-crystallins are a homogeneous group of highly symmetrical, monomeric proteins typically lacking connecting peptides and terminal extensions. They are differentially regulated after early development. This gene encodes a protein initially considered to be a beta-crystallin but the encoded protein is monomeric and has greater sequence similarity to other gamma-crystallins. This gene encodes the most significant gamma-crystallin in adult eye lens tissue. Whether due to aging or mutations in specific genes, gamma-crystallins have been involved in cataract formation. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.047430664).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CRYGS	NM_017541.4	c.352A>G	p.Ile118Val	missense_variant	3/3	ENST00000307944.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CRYGS	ENST00000307944.6	c.352A>G	p.Ile118Val	missense_variant	3/3	1	NM_017541.4	P1
CRYGS	ENST00000460288.1	n.1254A>G		non_coding_transcript_exon_variant	2/2	1
CRYGS	ENST00000392499.6	c.352A>G	p.Ile118Val	missense_variant	4/4	2		P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 07, 2023

The c.352A>G (p.I118V) alteration is located in exon 3 (coding exon 3) of the CRYGS gene. This alteration results from a A to G substitution at nucleotide position 352, causing the isoleucine (I) at amino acid position 118 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
CADD	Benign	12
DANN	Benign	0.70
DEOGEN2	Benign	0.16	T;T
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.88
FATHMM_MKL	Benign	0.19	N
M_CAP	Benign	0.0046	T
MetaRNN	Benign	0.047	T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.040	N;N
REVEL	Benign	0.11
Sift	Benign	1.0	T;T
Sift4G	Benign	0.65	T;T
Polyphen		0.0	B;B
Vest4		0.019
MutPred		0.52		Gain of catalytic residue at I118 (P = 0.152);Gain of catalytic residue at I118 (P = 0.152);
MVP		0.68
MPC		0.12
ClinPred		0.034	T
GERP RS		0.70
Varity_R		0.032
gMVP		0.21

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: rs1713989503; hg19: chr3-186256670;