22-26599552-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_001887.4(CRYBB1):c.697C>T(p.Arg233Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,614,014 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R233H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

CRYBB1
NM_001887.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.397

Variant links:

Genes affected

CRYBB1 (HGNC:2397): (crystallin beta B1) 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, undergoes extensive cleavage at its N-terminal extension during lens maturation. It is also a member of a gene cluster with beta-A4, beta-B2, and beta-B3. [provided by RefSeq, Jul 2008]

CRYBB1 links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr22-26599551-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2737022.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.888

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
CRYBB1	NM_001887.4 linkuse as main transcript	c.697C>T	p.Arg233Cys	missense_variant	6/6	ENST00000647684.1
CRYBB1	XM_011529899.4 linkuse as main transcript	c.697C>T	p.Arg233Cys	missense_variant	6/6
CRYBA4	XM_006724140.4 linkuse as main transcript	c.-239+2469G>A		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CRYBB1	ENST00000647684.1 linkuse as main transcript	c.697C>T	p.Arg233Cys	missense_variant	6/6		NM_001887.4	P1
	ENST00000668614.1 linkuse as main transcript	n.56+2469G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152252

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251198

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135834

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461762

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727184

show subpopulations

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:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000108

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74388

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000847

Hom.:

Bravo

AF:

0.0000113

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cataract 17 multiple types

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 24, 2022

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CRYBB1 protein function. This variant has not been reported in the literature in individuals affected with CRYBB1-related conditions. This variant is present in population databases (rs372169881, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 233 of the CRYBB1 protein (p.Arg233Cys). -

CRYBB1-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Jul 26, 2023

The CRYBB1 c.697C>T variant is predicted to result in the amino acid substitution p.Arg233Cys. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/22-26995516-G-A). A different nucleotide substitution affecting the same amino acid (p.Arg233His) was reported in the heterozygous state to segregate with congenital cataract in a family (Wang et al. 2011. PubMed ID: 21402992). At this time, the clinical significance of the c.697C>T (p.Arg233Cys) variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Pathogenic

0.25

BayesDel_noAF

Pathogenic

0.22

Cadd

Uncertain

Dann

Pathogenic

1.0

DEOGEN2

Benign

0.30

T;T

Eigen

Uncertain

0.64

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Uncertain

0.89

M_CAP

Uncertain

0.13

MetaRNN

Pathogenic

0.89

D;D

MetaSVM

Uncertain

0.47

MutationAssessor

Uncertain

2.7

M;M

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.49

Polyphen

1.0

D;D

Vest4

0.90

MVP

0.90

MPC

1.2

ClinPred

0.96

GERP RS

3.1

Varity_R

0.87

gMVP

0.62

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