In summary, these results suggest that ciliopathy-related genes BBS1, BBS5, BBS7, BBS9, BBS10, BBS11 [TRIM32], BBS12, KIF7, NPHP1 and TMEM216, differentially modulate appropriate patterns of post-migratory neuronal differentiation in cerebral cortex, including axonal growth, axonal guidance, neurite extension and arborization. The gene discussed is BBS12; the disease is ciliopathy.