OFD1 and retinitis pigmentosa: The OFD1 (oral-facial-digital 1) gene was initially identified in oral-facial-digital syndrome (OMIM 311200) [13] and is responsible for other ciliopathies such as Joubert syndrome [14], Simpson-Golabi-Behmel syndrome type 2 [15], and retinitis pigmentosa (RP) [16].