Consanguinity and Eye Diseases with a Potential Genetic Etiology. Data from a Prevalence Study in Andhra Pradesh, India

Abstract

Purpose: To determine the prevalence of consanguinity and its potential associations with eye diseases in Andhra Pradesh state of south India. Methods: As part of a demographic interview schedule, prior to clinical examinations, trained investigators collected information regarding consanguinity of the parents from subjects randomly chosen for a population-based cross-sectional epidemiological study. Each subject underwent a detailed ocular examination including visual acuity measurements, anterior segment examinations with slit-lamp biomicroscopy, and posterior segment examinations. Adjusted odds ratios (OR), attributable risks (AR) and population attributable risks (PAR) were estimated. Results: We obtained details regarding consanguinity of the parents from 10,290 of the 10,293 subjects who were enumerated and examined in the study. Parental consanguinity was reported by 1822 (24.7%) rural subjects and 782 (32.9%) urban subjects. Eighty (0.008%, 95% CI: 0.006, 0.010) of the 9757 subjects had an ocular disease with a potential genetic basis. We found microcornea to be significantly associated with both an uncle-niece relationship (adjusted OR: 7.32, 95% CI: 1.73, 30.97, AR = 86.34%, PAR = 42.11%) and a first-cousin relationship between the parents (adjusted OR 4.51, 95% CI: 1.05, 19.40, AR = 77.83%, PAR = 29.02%). Retinitis pigmentosa was significantly associated with a first-cousin relationship between the parents (adjusted OR: 5.31, 95% CI: 1.00, 28.25, AR = 81.17%, PAR = 33.43%). Conclusions: The high prevalence of consanguinity in this population does not appear to translate into a high prevalence of ocular malformations; however, studies with larger sample sizes are required to further explore the strength of these associations.