Genetics of syndromic ocular coloboma: CHARGE and COACH syndromes

• Published in: Experimental eye research 2020-04, Vol.193, p.107940-107940, Article 107940
• Main Authors: George, Aman, Cogliati, Tiziana, Brooks, Brian P.
• Format: Article
• Language: English
• Subjects: Abnormalities, Multiple - genetics; Animals; Ataxia - genetics; Brain - abnormalities; Cholestasis - genetics; Coloboma - genetics; Genetic Predisposition to Disease; Humans; Liver Diseases - genetics; Uvea - abnormalities
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/j.exer.2020.107940

Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed. •Uveal coloboma, a rare potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births.•Isolated and syndromic cases of uveal coloboma.•Current knowledge on the genetics of human uveal coloboma with a specific focus on CHARGE and COACH syndromes.•Approaches to identify genes involved in optic fissure closure using animal models.•Live imaging of zebrafish eye development to understand optic fissure closure.