Although WNT signaling was not investigated in the Cep290 (centrosomal protein 290 kDa) mutants, the data suggest that a WNT signaling defects might also underlie Joubert syndrome caused by mutations in Joubert-associated genes other than AHI1. This study clearly implicates deregulated WNT signaling as a mechanism in Joubert syndrome. This evidence concerns the gene AHI1 and Joubert syndrome.