NM_004076.5:c.466G>A

Variant names:

• chr22-25205358-G-A
• rs1203386884
• NM_004076.5:c.466G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_004076.5(CRYBB3):​c.466G>A​(p.Gly156Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,150 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CRYBB3 NM_004076.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 9.03

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a chain Beta-crystallin B3 (size 210) in uniprot entity CRBB3_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_004076.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 22-25205358-G-A is Pathogenic according to our data. Variant chr22-25205358-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 534700.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=2}. Variant chr22-25205358-G-A is described in Lovd as [Likely_pathogenic]. Variant chr22-25205358-G-A is described in Lovd as [Pathogenic]. Variant chr22-25205358-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRYBB3	NM_004076.5	c.466G>A	p.Gly156Arg	missense_variant	Exon 5 of 6	ENST00000215855.7	NP_004067.1
CRYBB3	XM_047441147.1	c.466G>A	p.Gly156Arg	missense_variant	Exon 4 of 5		XP_047297103.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRYBB3	ENST00000215855.7	c.466G>A	p.Gly156Arg	missense_variant	Exon 5 of 6	1	NM_004076.5	ENSP00000215855.2
CRYBB3	ENST00000404334.1	c.327+1463G>A		intron_variant	Intron 4 of 4	3		ENSP00000386123.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152150 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152150 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74326

Gnomad4 AFR AF: 0.0000241

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: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cataract 22 multiple types Pathogenic:2

Apr 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 156 of the CRYBB3 protein (p.Gly156Arg). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individual(s) with autosomal dominant congenital cataract (PMID: 27307692, 32830442, 33510601, 34014271). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 534700). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This variant disrupts the p.Gly156 amino acid residue in CRYBB3. Other variant(s) that disrupt this residue have been observed in individuals with CRYBB3-related conditions (PMID: 34356085), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Dec 27, 2023

3billion

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Predicted Consequence/Location: Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.96 (>=0.6, sensitivity 0.68 and specificity 0.92)]. Same nucleotide change resulting in same amino acid change has been previously reported to be associated with CRYBB3 related disorder (ClinVar ID: VCV000534700). The variant has been previously reported as assumed (i.e. paternity and maternity not confirmed) de novo in at least one similarly affected unrelated individual (PMID: 33510601). A different missense change at the same codon (p.Gly156Glu) has been reported to be associated with CRYBB3 related disorder (ClinVar ID: VCV001704644 /PMID: 34356085). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided Pathogenic:1 Uncertain:1

Nov 01, 2018

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 17, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 35011756, 33494148, 33510601, 27307692, 34014271, 32830442) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.60	D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.4	H
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-7.7	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.93		Gain of MoRF binding (P = 0.0083);
MVP		0.96
MPC		0.71
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.98
gMVP		0.86

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

Other links and lift over

dbSNP: rs1203386884; hg19: chr22-25601325;