Malay premature infants with retinopathy of prematurity: risk factors and screening of NDP gene mutation

The aim of this study is to determine the risk factors for retinopathy of prematurity (ROP), and also to screen Norrie Disease Pseudoglioma (NDP) gene mutation in order to determine if mutation in the NDP gene may play a role in the development of ROP among Malay premature infants. This was a case control study among Malay premature infants from Hospital Universiti Sains Malaysia (USM) conducted from August 2011 to May 2013. Written consent were taken from their parents before conducting the study. The stage of ROP, systemic risk factors (gestational age and birth weight) and enviromental risk factors (oxygen exposure and duration of ventilation) were reviewed from patients’ medical records. DNA was extracted from venous blood and subjected to polymerase chain reaction (PCR) before direct sequencing of NDP gene. A total of 56 Malay premature infants (Case group = 28 ROP premature infants, Control group = 28 non-ROP premature infants) from Hospital USM were enrolled in this study. Out of 28 premature infants with ROP, 11 (39.3%) premature infants were in stage 3. Only 1 (3.6%) premature infant in stage 4 and 2 (7.2%) premature infants in stage 5. The gestational age (p = 0.010) and birth weight (p = 0.010) were the significant risk factors for ROP. There was no significant difference of environmental risk factors between the two groups. The NDP gene mutation was not detected in Malay premature infants with ROP and also in control group. The gestational age and birth weight were important risk factors of ROP. Although NDP gene mutations were being linked to ROP but NDP gene mutation was not detected in premature infants with ROP as well as premature infants with non-ROP among Malay ethnic background.