MERTK and retinitis pigmentosa 1: Similarly, 5 out of the 7 Jewish Moroccan RP families presented the same homozygous variant in EYS. These peculiarities were also found in non-Jewish North African families, with 4 out of 8 RP families related to the homozygous c.2189 + 1G > T MERTK mutation; and virtually all RP families with CERKL variants presented the unique c.1133 + 3_1133 + 6delAAGT mutation at a homozygous state, all being of Tunisian ancestry.