chr22-25227921-G-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP2BP4BS2

The NM_000496.3(CRYBB2):c.242G>A(p.Arg81His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000229 in 1,614,118 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 28)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CRYBB2
NM_000496.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.38

Publications

1 publications found

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 Gene-Disease associations (from GenCC):

cataract 3 multiple types
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
cataract - microcornea syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
cerulean cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
early-onset nuclear cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
early-onset posterior subcapsular cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
early-onset sutural cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
pulverulent cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
total early-onset cataract
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

CRYBB2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000496.3

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 13 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.0723 (below the threshold of 3.09). Trascript score misZ: 1.7369 (below the threshold of 3.09). GenCC associations: The gene is linked to cataract 3 multiple types, pulverulent cataract, cataract - microcornea syndrome, early-onset posterior subcapsular cataract, total early-onset cataract, early-onset nuclear cataract, cerulean cataract, early-onset sutural cataract.

BP4

Computational evidence support a benign effect (MetaRNN=0.3955272).

BS2

High AC in GnomAd4 at 15 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYBB2	NM_000496.3 link	c.242G>A	p.Arg81His	missense_variant	Exon 4 of 6	ENST00000398215.3	NP_000487.1	P43320R4UMM2
CRYBB2	XM_006724141.4 link	c.242G>A	p.Arg81His	missense_variant	Exon 4 of 6		XP_006724204.1	P43320R4UMM2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYBB2	ENST00000398215.3 link	c.242G>A	p.Arg81His	missense_variant	Exon 4 of 6	1	NM_000496.3	ENSP00000381273.2		P43320
CRYBB2	ENST00000651629.1 link	c.242G>A	p.Arg81His	missense_variant	Exon 4 of 6			ENSP00000498905.1		P43320

Frequencies

GnomAD3 genomes

AF:

0.0000986

AC:

AN:

152120

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000338

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000398

AC:

AN:

251380

AF XY:

0.0000515

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000150

AC:

AN:

1461880

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727240

show subpopulations

African (AFR)

AF:

0.0000896

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000135

AC:

AN:

1112010

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.480

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000985

AC:

AN:

152238

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74434

show subpopulations

African (AFR)

AF:

0.000337

AC:

AN:

41548

American (AMR)

AF:

0.00

AC:

AN:

15308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4816

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68000

Other (OTH)

AF:

0.00

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000106

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cataract 3 multiple types

Uncertain:1

Nov 01, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is present in population databases (rs146763276, gnomAD 0.05%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with CRYBB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 463970). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). 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. This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 81 of the CRYBB2 protein (p.Arg81His). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.56

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.13

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.44

Eigen

Uncertain

0.36

Eigen_PC

Uncertain

0.35

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

0.98

M_CAP

Benign

0.031

MetaRNN

Benign

0.40

MetaSVM

Uncertain

-0.15

MutationAssessor

Benign

1.8

PhyloP100

7.4

PrimateAI

Pathogenic

0.88

PROVEAN

Uncertain

-4.4

REVEL

Pathogenic

0.68

Sift

Benign

0.039

Sift4G

Benign

0.18

Polyphen

1.0

Vest4

0.36

MVP

0.71

MPC

0.64

ClinPred

0.25

GERP RS

4.1

Varity_R

0.52

Mutation Taster

=42/58

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over