CTSD and Lesch-Nyhan syndrome: Interestingly, Ctsd, Atp7a, Clcn2 and Hprt1, the genes responsible for other human neurological disorders such as neuronal ceroid lipofuscinosis (Ctsd), Menkes disease (Atp7a), epilepsy (Clcn2), and Lesch-Nyhan syndrome (Hprt1), are associated with App and Mapt. These candidate genes are also involved in cell morphogenesis, assembly and organization and could be linked to deterioration of neurons during the pathologic progression of these disorders.