Ataxia with oculomotor apraxia type 2 (AOA2)/autosomal recessive spinocerebellar ataxia with axonal neuropathy-2 (SCAN2) (OMIM #606002) is characterized by early-onset progressive cerebellar ataxia, polyneuropathy, and elevated levels of alpha-fetoprotein (AFP). The gene discussed is AFP; the disease is polyneuropathy.