Autosomal recessive mutations in ARL3 or ARL13B cause Joubert Syndrome (Glass et al., 1993), while autosomal recessive mutations in ARL6 (also known as BBS3) lead to Bardet–Biedl Syndrome (Forsyth and Gunay-Aygun, 1993). This evidence concerns the gene ARL6 and Bardet-Biedl syndrome.