In general, approximately one-third of<unk> s are a component of a more extensive syndrome or disease (e.g., cataract resulting from<unk>  rubella syndrome), one-third occur as an isolated inherited trait, and one-third result from undetermined causes. Metabolic diseases tend to be more commonly associated with bilateral cataracts. Genetic & Metabolic Infections Anomalies Toxic Down syndrome Hallermann-Streiff syndrome Lowe syndrome Galactosemia Cockayne syndrome Marfan syndrome Trisomy 13- 15 Hypoglycemia Alport syndrome Myotonic dystrophy Fabry disease Hypoparathyroidism Conradi syndrome Incontinentia pigmenti Toxoplasmosis Other (Coxsackievirus, Syphilis, Varicella-Zoster, HIV, and Parvo B19) Rubella Cytomegalovirus Herpes Simplex (HSV-1, HSV-2) Aniridia Anterior segment dysgenesis Persistent fetal vasculature (PFV) Posterior lenticonus Corticosteroids Radiation Ultrasound axial scan of the fetal head with eye movements and a unilateral lens opacity seen at 20 weeks of pregnancy Genetics Approximately 50% of all<unk>  cases may have a genetic cause which is quite heterogeneous. It is known that different mutations in the same gene can cause similar cataract patterns, while the highly variable morphologies of cataracts within some families suggest that the same mutation in a single gene can lead to different phenotypes. More than 25 loci and genes on different chromosomes have been associated with<unk> . Mutations in distinct genes, which encode the main cytoplasmic proteins of human lens, have been associated with cataracts of various morphologies, including genes encoding crystallins (CRYA, CRYB, and CRYG), lens specific connexins (Cx43, Cx46, and Cx50), major intrinsic protein (MIP) or Aquaporin, cytoskeletal structural proteins, paired-like homeodomain transcription factor 3 (PITX3), avian musculoaponeurotic fibrosarcoma (MAF), and heat shock transcription factor 4 (HSF4).
Congenital cataract
Childhood cataract
Corneal dystrophy
Macular corneal dystrophy
Motion-induced blindness
Cystic eyeball
Granular corneal dystrophy
Fundic gland polyposis