TDP1 and Pes cavus: Due to the above observation, Duquette et al. [18] emphasized that OMA is not a universal finding in AOA2 and suggested the name “spinocerebellar ataxia, autosomal recessive, with axonal neuropathy-2” (SCAN2) to distinguish it from SCAN1 (OMIM #607250), which is caused by a homozygous mutation in the TDP1 gene and characterized by cerebellar ataxia with atrophy, peripheral axonal sensorimotor neuropathy, distal amyotrophy, and pes cavus without elevated levels of AFP or eye abnormalities [10].