Abstract 787
Retinopathy of prematurity (ROP) is a disease characterized by retinal neovascularization, possibly leading to retinal detachment and finally blindness. It occurs in premature newborns and its incidence and severity is inversely related to gestational age, birth weight and to other etiological factors such as oxygen, but the exact pathophysiology is unknown. Recently, Shastry et al. 1997 reported an association between missense mutations in exon 3 of the Norrie disease (ND) gene and advanced ROP in their US patients. We have investigated the presence of ND gene mutations in 76 Kuwaiti consecutive premature newborns admitted to the neonatal unit. 43/76 (57%) of these newborn babies had normal eyes and thus served as controls. In 23/76 (30%) of cases the ROP regressed spontaneously during stages 1-3. In 10/76 (13%) of cases, the ROP progressed to advanced stage beyond stage 3. ND gene mutations in these three groups were analysed by a PCR-RFLP method using two restrictions enzymes MspI and HaeIII to cleave the ND-gene exon-3 PCR product. Using this method, we did not find any differences at the R121W locus between the three groups of newborn babies and our populations appear to have a uniform genotype [RR] irrespective of ROP state in contrast to that reported by Shastry et al. However, in one family, we detected a heterozygous genotype [LP] at the L108P locus in a pair of twins, one of whom had a normal eyes while the other had a spontaneously regressed ROP. Additional screening and polymorphism is still in process.
