22-25201401-C-T

Position:

chr22-25201401-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4BS1_Supporting

The NM_004076.5(CRYBB3):c.5C>T(p.Ala2Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000279 in 1,612,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A2A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CRYBB3
NM_004076.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.46

Variant links:

Genes affected

CRYBB3 (HGNC:2400): (crystallin beta B3) 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 basic group member, is part of a gene cluster with beta-A4, beta-B1, and beta-B2. Mutations in this gene result in cataract congenital nuclear autosomal recessive type 2. [provided by RefSeq, Feb 2013]

CRYBB3 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a modified_residue N-acetylalanine; in Beta-crystallin B3, N-terminally processed (size 0) in uniprot entity CRBB3_HUMAN

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.26597056).

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000125 (19/152086) while in subpopulation AFR AF= 0.000362 (15/41404). AF 95% confidence interval is 0.000223. There are 0 homozygotes in gnomad4. There are 10 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CRYBB3	NM_004076.5 linkuse as main transcript	c.5C>T	p.Ala2Val	missense_variant	2/6	ENST00000215855.7	NP_004067.1	P26998
CRYBB3	XM_047441147.1 linkuse as main transcript	c.5C>T	p.Ala2Val	missense_variant	1/5		XP_047297103.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRYBB3	ENST00000215855.7 linkuse as main transcript	c.5C>T	p.Ala2Val	missense_variant	2/6	1	NM_004076.5	ENSP00000215855.2		P26998
CRYBB3	ENST00000404334.1 linkuse as main transcript	c.5C>T	p.Ala2Val	missense_variant	2/5	3		ENSP00000386123.1		B1AHR5

Frequencies

GnomAD3 genomes

AF:

0.000125

AC:

AN:

152086

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000362

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251396

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135898

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000178

AC:

AN:

1460780

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

726680

show subpopulations

Gnomad4 AFR exome

AF:

0.000359

Gnomad4 AMR exome

AF:

0.0000448

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:

0.00000900

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.000125

AC:

AN:

152086

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74290

show subpopulations

Gnomad4 AFR

AF:

0.000362

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.000478

Alfa

AF:

0.0000564

Hom.:

Bravo

AF:

0.000155

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 30, 2024

The c.5C>T (p.A2V) alteration is located in exon 2 (coding exon 1) of the CRYBB3 gene. This alteration results from a C to T substitution at nucleotide position 5, causing the alanine (A) at amino acid position 2 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.30

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.024

T;T

Eigen

Benign

-0.40

Eigen_PC

Benign

-0.36

FATHMM_MKL

Uncertain

0.77

LIST_S2

Benign

0.61

T;T

M_CAP

Uncertain

0.17

MetaRNN

Benign

0.27

T;T

MetaSVM

Benign

-0.71

MutationAssessor

Benign

1.6

L;.

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-1.8

N;N

REVEL

Benign

0.17

Sift

Uncertain

0.0040

D;D

Sift4G

Uncertain

0.015

D;D

Polyphen

0.45

B;.

Vest4

0.35

MutPred

0.28

Gain of catalytic residue at E3 (P = 0.2133);Gain of catalytic residue at E3 (P = 0.2133);

MVP

0.58

MPC

0.18

ClinPred

0.26

GERP RS

2.3

Varity_R

0.062

gMVP

0.30

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over