Congenital primary aphakia (CPA) is characterized by an absence of the lens. The prevalence is unknown. CPA can be associated with variable secondary ocular defects (including aplasia/dysplasia of the anterior segment of the eye, microphthalmia, and in some cases absence of the iris, retinal dysplasia, or sclerocornea). CPA results from early developmental arrest, around the 4th-5th week of embryogenesis, which prevents the formation of any lens structure. Mutations in the FOXE3 gene were identified in three affected siblings born to consanguineous parents. The disease is MONDO_0012456 (congenital primary aphakia). Also known as: anterior segment dysgenesis 2, multiple subtypes, aphakia, congenital primary, congenital absence of lens, congenital aphakia.