CRYBA4 (Crystallin Beta A4)
A structural lens protein gene associated with congenital cataracts and microcornea
Gene Information Card
| Symbol | CRYBA4 |
|---|---|
| Full Name | Crystallin Beta A4 |
| Gene Type | Protein coding |
| Chromosomal Location | 22q12.1 |
| NCBI Gene ID | 1413 ncbi.nlm.nih.gov/gene/1413 |
| Ensembl ID | ENSG00000100207 |
| UniProt ID | P53673 |
| OMIM ID | 123631 |
| HGNC ID | 2396 |
| Aliases | CTRCT23, MCOPCT4, crystallin, beta A4 |
Description
CRYBA4 encodes beta-crystallin A4, a structural protein of the vertebrate eye lens. Beta-crystallins, along with gamma-crystallins, form the major soluble lens proteins and are critical for maintaining lens transparency and refractive index. Mutations in CRYBA4 are associated with autosomal dominant congenital cataracts and microcornea.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital cataract (CTRCT23) | Missense or frameshift mutations disrupt protein folding and solubility, leading to lens opacification | ClinVar, OMIM |
| Microcornea with cataract (MCOPCT4) | Loss-of-function variants impair lens development and corneal size regulation | OMIM, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lens | High | Tissue-specific |
| Retina | Low | Detectable |
| Brain | Not detected | - |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| ARPE-19 (retinal pigment epithelium) | Low | Minimal expression |
| HLE-B3 (human lens epithelial) | High | Endogenous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.167G>A (p.Arg56His) | Missense | Rare | Dominant negative; reduced solubility |
| c.238C>T (p.Arg80Cys) | Missense | Rare | Loss of function; cataract formation |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Complete loss of protein |
Mutation functional classification
Loss of Function (LOF)
Start-loss and frameshift mutations lead to truncated or absent protein, causing microcornea and cataract.
Gain of Function (GOF)
Not reported for CRYBA4.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg56His) produce misfolded protein that aggregates and disrupts lens transparency.
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of eye lens | • protein homodimerization activity |
| • identical protein binding | • lens development in camera-type eye |
| • visual perception |
Pathways
• Lens crystallin network
• Protein folding in endoplasmic reticulum
Protein Summary
Beta-crystallin A4 is a 22 kDa protein composed of four Greek-key motifs forming two domains. It functions as a homodimer or heterodimer with other beta-crystallins to maintain lens transparency. The protein is highly expressed in the lens and is resistant to thermal denaturation.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CRYBA4 Knockout HEK293 Cell Line | EDJ-KQ4354 | Human | 1413 | Details Get a Quote |
| CRYBA4 Knockout HeLa Cell Line | EDJ-KQ52990 | Human | 1413 | Details Get a Quote |
| CRYBA4 Knockout A-549 Cell Line | EDJ-KQ61457 | Human | 1413 | Details Get a Quote |
| CRYBA4 Knockout HCT 116 Cell Line | EDJ-KQ69954 | Human | 1413 | Details Get a Quote |
