PRPH2 and respiratory distress syndrome in premature infants: Among these, mutations in the peripherin 2 (PRPH2) gene (OMIM: 179605), also known as retinal degeneration slow (RDS) [3,4], are one of the most frequent causes of IRD [5] accounting for 4.6% of IRD cases in the UK [5], 3.4% in Japan [6], and 5% in Italy [7].