chr22-25207069-G-A

Position:

• chr22-25207069-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_004076.5(CRYBB3):​c.493G>A​(p.Gly165Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,613,580 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G165R) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: CRYBB3 NM_004076.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.28

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 8 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr22-25207069-G-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.887

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CRYBB3	NM_004076.5	c.493G>A	p.Gly165Ser	missense_variant	6/6	ENST00000215855.7	NP_004067.1
CRYBB3	XM_047441147.1	c.493G>A	p.Gly165Ser	missense_variant	5/5		XP_047297103.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRYBB3	ENST00000215855.7	c.493G>A	p.Gly165Ser	missense_variant	6/6	1	NM_004076.5	ENSP00000215855.2
CRYBB3	ENST00000404334.1	c.*8G>A		3_prime_UTR_variant	5/5	3		ENSP00000386123.1

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152190 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

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: 0.000376

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 249672 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135232

Gnomad AFR exome AF: 0.0000618

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000139

Gnomad NFE exome AF: 0.00000892

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1461390 Hom.: 0 Cov.: 31 AF XY: 0.0000138 AC XY: 10 AN XY: 727054

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000564

Gnomad4 NFE exome AF: 0.00000899

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152190 Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5 AN XY: 74348

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000376

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.25	T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.071	D
MutationAssessor	Uncertain	2.4	M
PrimateAI	Uncertain	0.51	T
PROVEAN	Pathogenic	-5.6	D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0050	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.68		Gain of sheet (P = 0.0827);
MVP		0.88
MPC		0.64
ClinPred		0.98	D
GERP RS		4.9
Varity_R		0.88
gMVP		0.46

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: rs74315490; hg19: chr22-25603036; COSMIC: COSV53194120;