CRYGB

Chr 2AD

crystallin gamma B

Also known as: CRYG2, CTRCT39

Gamma-B crystallin is a major structural protein of the vertebrate eye lens that maintains lens transparency and refractive index throughout life. Mutations cause autosomal dominant congenital cataracts, with affected infants presenting with lens opacities at birth or in early childhood. This gene shows very low constraint against loss-of-function variants, indicating tolerance to such mutations in the general population.

OMIMResearchSummary from RefSeq, UniProt
DNmechanismADLOEUF 1.821 OMIM phenotype
Clinical SummaryCRYGB
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.82LOEUF
pLI 0.000
Z-score -0.49
OE 1.18 (0.721.82)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.45Z-score
OE missense 1.12 (0.971.31)
120 obs / 106.8 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE1.18 (0.721.82)
00.351.4
Missense OE1.12 (0.971.31)
00.61.4
Synonymous OE1.11
01.21.6
LoF obs/exp: 10 / 8.5Missense obs/exp: 120 / 106.8Syn Z: -0.53
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
limitedCRYGB-related cataract, multiple typesOTHERAD
DN
0.7325th %ile
GOF
0.4085th %ile
LOF
0.4529th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CRYGB · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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