rs1555165595

Positions:

• chr11-111911685-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001289808.2(CRYAB):​c.40T>G​(p.Phe14Val) 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: 32)
• Consequence: CRYAB NM_001289808.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.47

Genes affected

CRYAB (HGNC:2389): (crystallin alpha B) Mammalian lens crystallins are divided into alpha, beta, and gamma families. Alpha crystallins are composed of two gene products: alpha-A and alpha-B, for acidic and basic, respectively. Alpha crystallins can be induced by heat shock and are members of the small heat shock protein (HSP20) family. They act as molecular chaperones although they do not renature proteins and release them in the fashion of a true chaperone; instead they hold them in large soluble aggregates. These heterogeneous aggregates consist of 30-40 subunits; the alpha-A and alpha-B subunits have a 3:1 ratio, respectively. Two additional functions of alpha crystallins are an autokinase activity and participation in the intracellular architecture. The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. Alpha-A and alpha-B gene products are differentially expressed; alpha-A is preferentially restricted to the lens and alpha-B is expressed widely in many tissues and organs. Elevated expression of alpha-B crystallin occurs in many neurological diseases; a missense mutation cosegregated in a family with a desmin-related myopathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2019]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CRYAB	NM_001289808.2	c.40T>G	p.Phe14Val	missense_variant	1/3	ENST00000650687.2	NP_001276737.1
CRYAB	NM_001289807.1	c.40T>G	p.Phe14Val	missense_variant	2/4		NP_001276736.1
CRYAB	NM_001368245.1	c.40T>G	p.Phe14Val	missense_variant	2/4		NP_001355174.1
CRYAB	NM_001885.3	c.40T>G	p.Phe14Val	missense_variant	2/4		NP_001876.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRYAB	ENST00000650687.2	c.40T>G	p.Phe14Val	missense_variant	1/3		NM_001289808.2	ENSP00000499082	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dilated cardiomyopathy 1II Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 27, 2017

This sequence change replaces phenylalanine with valine at codon 14 of the CRYAB protein (p.Phe14Val). The phenylalanine residue is moderately conserved and there is a small physicochemical difference between phenylalanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CRYAB-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.072	D
BayesDel_noAF	Benign	-0.13
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.45	T;T;T;T;T;T;T;T;T;T;T
Eigen	Benign	0.17
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Benign	0.79	.;T;.;.;.;.;.;T;T;T;.
M_CAP	Benign	0.070	D
MetaRNN	Uncertain	0.73	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.097	D
MutationAssessor	Benign	1.7	L;L;L;L;L;L;.;.;.;.;.
MutationTaster	Benign	0.99	D;D;D;D;D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-1.4	N;.;N;N;N;N;N;N;N;N;N
REVEL	Uncertain	0.49
Sift	Benign	0.031	D;.;D;D;D;D;D;T;D;D;D
Sift4G	Benign	0.29	T;T;T;T;T;T;.;.;D;.;.
Polyphen		0.019	B;B;B;B;B;B;.;.;P;.;.
Vest4		0.32
MutPred		0.65		Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);Loss of stability (P = 0.1436);
MVP		0.95
MPC		0.69
ClinPred		0.90	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.62
gMVP		0.86

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: rs1555165595; hg19: chr11-111782409;