22-26625461-A-T

Variant names:

• chr22-26625461-A-T
• rs4276
• NM_001886.3:c.159-20A>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001886.3(CRYBA4):​c.159-20A>T variant causes a intron 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CRYBA4 NM_001886.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.11
• Publications: 23 publications found

Genes affected

CRYBA4 (HGNC:2396): (crystallin beta A4) 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. Beta-crystallins, the most heterogeneous, differ by the presence of the C-terminal extension (present in the basic group, none in the acidic group). Beta-crystallins form aggregates of different sizes and are able to self-associate to form dimers or to form heterodimers with other beta-crystallins. This gene, a beta acidic group member, is part of a gene cluster with beta-B1, beta-B2, and beta-B3. [provided by RefSeq, Jul 2008]

CRYBA4 Gene-Disease associations (from GenCC):

• cataract 23

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

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

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.9).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYBA4	NM_001886.3	c.159-20A>T		intron_variant	Intron 3 of 5	ENST00000354760.4	NP_001877.1
CRYBA4	XM_006724140.4	c.174-20A>T		intron_variant	Intron 5 of 7		XP_006724203.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYBA4	ENST00000354760.4	c.159-20A>T		intron_variant	Intron 3 of 5	1	NM_001886.3	ENSP00000346805.3
CRYBA4	ENST00000466315.1	n.56-20A>T		intron_variant	Intron 2 of 4	5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 40

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 11676

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.90
CADD	Benign	0.036
DANN	Benign	0.51
PhyloP100		-1.1

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: rs4276; hg19: chr22-27021425;