To integrate knowledge on the embryologic and molecular basis of optic fissure closure with clinical observations in patients with uveal coloboma.
Closure of the optic fissure has been well characterized and many genetic alterations have been associated with coloboma; however, molecular mechanisms leading to coloboma remain largely unknown. In the past decade, we have gained better understanding of genes critical to eye development; however, mutations in these genes have been found in few individuals with coloboma. CHD7 mutations have been identified in patients with CHARGE syndrome (coloboma, heart defects, choanal atresia, retarded growth, genital anomalies, and ear anomalies or deafness). Animal models are bringing us closer to a molecular understanding of optic fissure closure.
Optic fissure closure requires precise orchestration in timing and apposition of two poles of the optic cup. The relative roles of genetics and environment on this process remain elusive. While most cases of coloboma are sporadic, autosomal dominant, autosomal recessive, and X-linked inheritance patterns have been described. Genetically, colobomata demonstrate pleiotropy, heterogeneity, variable expressivity, and reduced penetrance. Coloboma is a complex disorder with a variable prognosis and requires regular examination to optimize visual acuity and to monitor for potential complications.
aNational Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
bUniversity of Michigan Medical School, Ann Arbor, Michigan, USA
cNational Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
Correspondence to Brian P. Brooks, MD, PhD, 10 Center Drive, Building 10, Room 10N226, MSC 1860, Bethesda, MD 20892, USA Tel: +301 496 3577; fax: +301 402 1214; e-mail: firstname.lastname@example.org
This work was supported by the intramural program of the National Institutes of Health, US Department of Health and Human Services.