22-26616148-TC-T

Position:

chr22-26616148-TC-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001887.4(CRYBB1):c.171del(p.Asn58ThrfsTer107) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CRYBB1
NM_001887.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: -0.367

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:

CRYBA4 (HGNC:):

CRYBA4 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 22-26616148-TC-T is Pathogenic according to our data. Variant chr22-26616148-TC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 419532.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr22-26616148-TC-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
CRYBB1	NM_001887.4 linkuse as main transcript	c.171del	p.Asn58ThrfsTer107	frameshift_variant	2/6	ENST00000647684.1
CRYBB1	XM_011529899.4 linkuse as main transcript	c.171del	p.Asn58ThrfsTer107	frameshift_variant	2/6
CRYBA4	XM_006724140.4 linkuse as main transcript	c.4-6434del		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CRYBB1	ENST00000647684.1 linkuse as main transcript	c.171del	p.Asn58ThrfsTer107	frameshift_variant	2/6		NM_001887.4	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152144

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:

0.00316

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461798

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727216

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152262

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74442

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:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cataract 17 multiple types

Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 26, 2024	- -
Pathogenic, no assertion criteria provided	clinical testing	Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City	Feb 05, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 06, 2022	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	May 01, 2007	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 03, 2018

The c.171delG deletion in the CRYBB1 gene has been reported previously (including reported as delG168due to alternative nomenclature) in association with congenital cataracts (Cohen et al., 2007; Aldahmesh etal., 2012). The c.171delG deletion causes a frameshift starting with codon asparagine 58, changes thisamino acid to a threonine residue, and creates a premature Stop codon at position 107 of the new readingframe, denoted p.N58TfsX107. This variant is predicted to cause loss of normal protein function eitherthrough protein truncation or nonsense-mediated mRNA decay. The c.171delG deletion was not observedin approximately 6500 individuals of European and African American ancestry in the NHLBI ExomeSequencing Project, indicating it is not a common variant in these populations. We interpret c.171delG as a pathogenic variant. -

Cataract 17

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Hadassah Hebrew University Medical Center

Jun 20, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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