Spectrum of congenital and inherited ocular disorders seen in a genetic clinic: Experience of a developing ocular genetic service

Abstract

Purpose: Hereditary causes are an important etiological category of childhood blindness. This study reports the real-world experience of a developing ocular genetic service. Methods: The study was carried out from Jan 2020 to Dec 2021 jointly by the Pediatric Genetic Clinic and the Department of Ophthalmology of a tertiary care hospital in North-West India. Children presenting to the genetic clinic with congenital or late-onset ocular disorder(s) and any individual (irrespective of age) suffering from an ophthalmic disorder and referred by an ophthalmologist for genetic counseling for himself/herself and/or his/her family member(s) were included. Genetic testing (exome sequencing/panel-based sequencing/chromosomal microarray) was outsourced to third-party laboratories with the cost of the test being borne by the patient. Results: Exactly 8.6% of the registered patients in the genetic clinic had ocular disorders. Maximum number of patients belonged to the category of anterior segment dysgenesis, followed by microphthalmia anophthalmia coloboma spectrum, lens disorders, and inherited retinal disorders in decreasing numbers. The ratio of syndromic ocular to isolated ocular disorders seen was 1.8:1. Genetic testing was accepted by 55.5% of families. The genetic testing was clinically useful for ~35% of the tested cohort, with the opportunity for prenatal diagnosis being the most useful application of genetic testing. Conclusion: Syndromic ocular disorders are seen at a higher frequency compared to isolated ocular disorders in a genetic clinic. Opportunity for prenatal diagnosis is the most useful application of genetic testing in ocular disorders.

Keywords

• anterior segment dysgenesis
• exome sequencing
• inherited retinal diseases
• microphthalmia anophthalmia coloboma spectrum