These previous IFT74 mutations were described to cause different primary ciliopathy subtypes including both Bardet–Biedl syndrome (BBS) expressed with postaxial polydactyly, retinal degeneration, obesity, intellectual disability, and hypogonadism (43,44,47,58) and Joubert syndrome (JS) expressed with postaxial polydactyly, developmental delay, subtle cleft upper lip, and molar tooth sign of the brain but no retinal anomalies or significant obesity (46,59). Here, IFT74 is linked to Intellectual disability.