# Catarata polar posterior de início precoce

> Página oficial: https://raras.org/doenca/catarata-polar-posterior-de-inicio-precoce
> Fonte: Raras.org — Banco de Dados de Doenças Raras em Português (CC BY-NC-SA 4.0)
> Última atualização: 2026-05-07

## Identificadores

- **ORPHA**: 98993 — https://www.orpha.net/en/disease/detail/98993
- **CID-10**: Q12.0
- **OMIM**: none — https://omim.org/entry/none

## Descrição clínica

Catarata polar posterior de início precoce é uma opacidade congênita ou de início na infância, localizada na parte posterior do cristalino. Frequentemente associada a mutações nos genes CRYAB, CHMP4B, MIP, PITX3 ou PANK4, pode afetar a visão desde cedo.

## Epidemiologia e herança


## Genes associados (8)

- **CRYAB** — Alpha-crystallin B chain [Disease-causing germline mutation(s) in]
  - Função: May contribute to the transparency and refractive index of the lens. Has chaperone-like activity, preventing aggregation of various proteins under a wide range of stress conditions. In lens epithelial
- **CHMP4B** — Charged multivesicular body protein 4b [Disease-causing germline mutation(s) in]
  - Função: Probable core component of the endosomal sorting required for transport complex III (ESCRT-III) which is involved in multivesicular bodies (MVBs) formation and sorting of endosomal cargo proteins into
- **MIP** — Lens fiber major intrinsic protein [Disease-causing germline mutation(s) in]
  - Função: Aquaporins form homotetrameric transmembrane channels, with each monomer independently mediating water transport across the plasma membrane along its osmotic gradient (PubMed:11001937, PubMed:24120416
- **PITX3** — Pituitary homeobox 3 [Disease-causing germline mutation(s) in]
  - Função: Transcriptional regulator which is important for the differentiation and maintenance of meso-diencephalic dopaminergic (mdDA) neurons during development. In addition to its importance during developme
- **PANK4** — 4'-phosphopantetheine phosphatase [Disease-causing germline mutation(s) in]
  - Função: Phosphatase which shows a preference for 4'-phosphopantetheine and its oxidatively damaged forms (sulfonate or S-sulfonate), providing strong indirect evidence that the phosphatase activity pre-empts
- **CRYBA1** — Beta-crystallin A3 [Disease-causing germline mutation(s) in]
  - Função: Crystallins are the dominant structural components of the vertebrate eye lens
- **EPHA2** — Ephrin type-A receptor 2 [Disease-causing germline mutation(s) in]
  - Função: Receptor tyrosine kinase which binds promiscuously membrane-bound ephrin-A family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The s
- **GJA3** — Gap junction alpha-3 protein [Disease-causing germline mutation(s) in]
  - Função: Structural component of lens fiber gap junctions (PubMed:30044662). Gap junctions are dodecameric channels that connect the cytoplasm of adjoining cells (By similarity). They are formed by the docking

## Importante

O Raras **não diagnostica e não prescreve**. Esta página é educativa e informativa.
Pacientes devem consultar profissionais de saúde qualificados para decisões clínicas.

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**Citação sugerida**: Raras.org — Catarata polar posterior de início precoce. Disponível em: https://raras.org/doenca/catarata-polar-posterior-de-inicio-precoce
**Formato HTML**: https://raras.org/doenca/catarata-polar-posterior-de-inicio-precoce
**Formato RDF/Turtle**: https://raras.org/api/rdf?orpha=98993