Objectives: The goals were to isolate and to estimate the genetic susceptibility to retinopathy of prematurity.
Methods: A retrospective study (1994-2004) from 3 centers was performed with zygosity data for premature twins who were born at a gestational age of < or = 32 weeks and survived beyond a postmenstrual age of 36 weeks. Retinopathy of prematurity was diagnosed and staged by pediatric ophthalmologists at each center. Data analyses were performed with mixed-effects logistic regression analysis and latent variable probit modeling.
Results: A total of 63 monozygotic and 137 dizygotic twin pairs were identified and analyzed. Data on gestational age, birth weight, gender, respiratory distress syndrome, retinopathy of prematurity, bronchopulmonary dysplasia, duration of ventilation and supplemental oxygen use, and length of stay were comparable between monozygotic and dizygotic twins. In the mixed-effects logistic regression analysis for retinopathy of prematurity, gestational age and duration of supplemental oxygen use were significant covariates. After controlling for known and unknown nongenetic factors, genetic factors accounted for 70.1% of the variance in liability for retinopathy of prematurity.
Conclusion: In addition to prematurity and environmental factors, there is a strong genetic predisposition to retinopathy of prematurity.