2-208129538-T-G

Variant names:

• chr2-208129538-T-G
• rs1553585708
• NM_020989.4:c.155A>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_020989.4(CRYGC):​c.155A>C​(p.Gln52Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CRYGC NM_020989.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0990
• Publications: 0 publications found

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]

CRYGC Gene-Disease associations (from GenCC):

• cataract 2, multiple types

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• cataract - microcornea syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset lamellar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset nuclear cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pulverulent cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000295187 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020989.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRYGC	NM_020989.4	MANE Select	c.155A>C	p.Gln52Pro	missense	Exon 2 of 3	NP_066269.1
	LOC100507443	NR_038437.1		n.98-7518T>G		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRYGC	ENST00000282141.4	TSL:1 MANE Select	c.155A>C	p.Gln52Pro	missense	Exon 2 of 3	ENSP00000282141.3
	ENSG00000295187	ENST00000728538.1		n.101-7518T>G		intron	N/A
	ENSG00000295187	ENST00000728539.1		n.118-7518T>G		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nuclear pulverulent cataract Uncertain:1

Jun 16, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine with proline at codon 52 of the CRYGC protein (p.Gln52Pro). The glutamine residue is moderately conserved and there is a moderate physicochemical difference between glutamine and proline. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a CRYGC-related disease. 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 tolerated, but these predictions have not been confirmed by published functional studies. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Benign	-0.019	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	17
DANN	Benign	0.94
DEOGEN2	Uncertain	0.60	D
Eigen	Benign	-0.68
Eigen_PC	Benign	-0.75
FATHMM_MKL	Benign	0.12	N
M_CAP	Benign	0.034	D
MetaRNN	Uncertain	0.52	D
MetaSVM	Benign	-0.73	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		-0.099
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-2.0	N
REVEL	Uncertain	0.43
Sift	Benign	0.17	T
Sift4G	Benign	0.24	T
Polyphen		0.0040	B
Vest4		0.60
MutPred		0.54		Gain of glycosylation at Q52 (P = 0.0409)
MVP		0.76
MPC		0.13
ClinPred		0.27	T
GERP RS		-4.8
PromoterAI		-0.034	Neutral
Varity_R		0.80
gMVP		0.66
Mutation Taster		=69/31	polymorphism

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

Other links and lift over

dbSNP: rs1553585708; hg19: chr2-208994262;