CRYBB2: Crystallin Beta B2
A key structural protein of the eye lens, mutations in which cause congenital cataracts.
Gene Information Card
| Symbol | CRYBB2 |
|---|---|
| Full Name | crystallin beta B2 |
| Gene Type | protein-coding |
| Chromosomal Location | 22q11.23 |
| NCBI Gene ID | 1415 ncbi.nlm.nih.gov/gene/1415 |
| Ensembl ID | ENSG00000100207 |
| UniProt ID | P43320 |
| OMIM ID | 123620 |
| HGNC ID | 2396 |
| Aliases | CCA2, CRYB2, CRYB2A, CTRCT3, MCOPCT4 |
Description
CRYBB2 encodes beta-crystallin B2, a structural protein that is a major component of the vertebrate eye lens. It contributes to lens transparency and refractive index. Mutations in this gene are associated with autosomal dominant congenital cataracts and other lens disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital cataract (AD) | Missense or truncating mutations disrupt protein folding and lens clarity | ClinVar, OMIM |
| Microcornea with cataract | Specific missense variants impair lens development | ClinVar |
| Cataract 3 (CTRCT3) | Dominant mutations in CRYBB2 cause this form | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Eye (lens) | High | Tissue-specific |
| Brain | Low | Non-lens expression |
| Testis | Low | Non-lens expression |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| ARPE-19 (retinal pigment epithelium) | Low | Non-lens cell line |
| HUVEC (umbilical vein endothelial) | Not detected | Non-ocular cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.475C>T (p.Arg159Trp) | Missense | Rare | Dominant negative; causes congenital cataract |
| c.475C>A (p.Arg159Gln) | Missense | Rare | Dominant negative; causes congenital cataract |
| c.1A>G (p.Met1Val) | Start loss | Rare | Loss of function; causes cataract |
Mutation functional classification
Loss of Function (LOF)
Start loss mutations (e.g., p.Met1Val) reduce protein production.
Gain of Function (GOF)
Not reported for CRYBB2.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg159Trp) disrupt protein folding and aggregate with wild-type, causing cataract.
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of eye lens | • protein homodimerization activity |
| • identical protein binding |
Pathways
• Lens development
• Crystallin aggregation in cataract
Protein Summary
Beta-crystallin B2 is a 205-amino acid protein that forms homodimers and heterodimers with other crystallins. It is highly expressed in the lens and maintains transparency through ordered packing. Mutations cause protein aggregation and lens opacification.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CRYBB2 Knockout HEK293 Cell Line | EDJ-KQ3632 | Human | 1415 | Details Get a Quote |
| CRYBB2 Knockout HeLa Cell Line | EDJ-KQ52992 | Human | 1415 | Details Get a Quote |
| CRYBB2 Knockout A-549 Cell Line | EDJ-KQ61459 | Human | 1415 | Details Get a Quote |
| CRYBB2 Knockout HCT 116 Cell Line | EDJ-KQ69956 | Human | 1415 | Details Get a Quote |
