21-43169070-C-G

Position:

• chr21-43169070-C-G

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000394.4(CRYAA):​c.-30C>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 11)
• Consequence: CRYAA NM_000394.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.50

Genes affected

CRYAA (HGNC:2388): (crystallin alpha A) 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. Post-translational modifications decrease the ability to chaperone. 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. Defects in this gene cause autosomal dominant congenital cataract (ADCC). [provided by RefSeq, Jan 2014]

LOC107987300 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CRYAA	NM_000394.4	c.-30C>G		5_prime_UTR_variant	1/3	ENST00000291554.6	NP_000385.1
LOC107987300	XR_007067885.1	n.546+1967G>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRYAA	ENST00000291554	c.-30C>G		5_prime_UTR_variant	1/3	1	NM_000394.4	ENSP00000291554.2
CRYAA	ENST00000482775.1	n.-17C>G		upstream_gene_variant		5

Frequencies

GnomAD3 genomes Cov.: 11

GnomAD4 exome Cov.: 20

GnomAD4 genome Cov.: 11

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cataract 9 multiple types Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	9.7
DANN	Benign	0.76

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: rs1985729237; hg19: chr21-44589180;