dbSNP rs776245335: CRYBB2:p.Ala9Glu (chr22-25221455-C-A) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM1BP4_ModerateBS2_Supporting

The NM_000496.3(CRYBB2):c.26C>A(p.Ala9Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,396 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict 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: 0.0000055 ( 0 hom. )

Consequence

CRYBB2
NM_000496.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.878

Variant links:

Genes affected

CRYBB2 (HGNC:2398): (crystallin beta B2) 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-B3. A chain-terminating mutation was found to cause type 2 cerulean cataracts. [provided by RefSeq, Jul 2008]

CRYBB2 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM1

In a chain Beta-crystallin B2 (size 203) in uniprot entity CRBB2_HUMAN there are 23 pathogenic changes around while only 1 benign (96%) in NM_000496.3

BP4

Computational evidence support a benign effect (MetaRNN=0.13010123).

BS2

High AC in GnomAdExome4 at 8 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYBB2	NM_000496.3 link	c.26C>A	p.Ala9Glu	missense_variant	Exon 2 of 6	ENST00000398215.3	NP_000487.1	P43320R4UMM2
CRYBB2	XM_006724141.4 link	c.26C>A	p.Ala9Glu	missense_variant	Exon 2 of 6		XP_006724204.1	P43320R4UMM2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYBB2	ENST00000398215.3 link	c.26C>A	p.Ala9Glu	missense_variant	Exon 2 of 6	1	NM_000496.3	ENSP00000381273.2		P43320
CRYBB2	ENST00000651629.1 link	c.26C>A	p.Ala9Glu	missense_variant	Exon 2 of 6			ENSP00000498905.1		P43320

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250918

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135740

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461396

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727008

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:

0.00000720

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.075

BayesDel_noAF

Benign

-0.25

CADD

Benign

DANN

Benign

0.96

DEOGEN2

Benign

0.17

Eigen

Benign

-0.35

Eigen_PC

Benign

-0.23

FATHMM_MKL

Uncertain

0.83

LIST_S2

Benign

0.56

M_CAP

Benign

0.031

MetaRNN

Benign

0.13

MetaSVM

Benign

-0.87

MutationAssessor

Uncertain

2.3

PrimateAI

Benign

0.46

PROVEAN

Benign

-1.4

REVEL

Benign

0.17

Sift

Benign

0.095

Sift4G

Benign

0.13

Polyphen

0.17

Vest4

0.24

MutPred

0.23

Loss of catalytic residue at A9 (P = 0.0423);

MVP

0.61

MPC

0.53

ClinPred

0.51

GERP RS

1.4

Varity_R

0.16

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

Computational scores

Splicing

Publications

LitVar

Other links and lift over