2-218991975-T-G

Variant names:

• chr2-218991975-T-G
• NM_057093.2:c.303+127A>C

Variant summary

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

The NM_057093.2(CRYBA2):​c.303+127A>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 606,172 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 32)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: CRYBA2 NM_057093.2 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.53

Genes affected

CRYBA2 (HGNC:2395): (crystallin beta A2) Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of the vertebrate eye, which function to maintain 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 defined 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 but absent in the acidic group). Beta-crystallins form aggregates of different sizes and are able to form homodimers through self-association or heterodimers with other beta-crystallins. This gene is a beta acidic group member. Three alternatively spliced transcript variants encoding identical proteins have been reported. [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 (BayesDel_noAF=-0.87).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYBA2	NM_057093.2	c.303+127A>C		intron_variant	Intron 2 of 3	ENST00000295728.7	NP_476434.1
CRYBA2	NM_057094.2	c.303+127A>C		intron_variant	Intron 3 of 4		NP_476435.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYBA2	ENST00000295728.7	c.303+127A>C		intron_variant	Intron 2 of 3	1	NM_057093.2	ENSP00000295728.2
CRYBA2	ENST00000392096.6	c.303+127A>C		intron_variant	Intron 3 of 4	1		ENSP00000375946.2
CRYBA2	ENST00000453769.1	c.303+127A>C		intron_variant	Intron 3 of 3	3		ENSP00000395120.1
CRYBA2	ENST00000490678.1	n.432A>C		non_coding_transcript_exon_variant	Exon 2 of 2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000198 AC: 12 AN: 606172 Hom.: 0 Cov.: 8 AF XY: 0.0000226 AC XY: 7 AN XY: 310320

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000289

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	5.8
DANN	Benign	0.56

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-219856697;