Another NBIA-gene with a role in lipid metabolism is FA2H (fatty acid 2-hydroxylase), whose mutations lay at the basis of Fatty Acid Hydroxylase-Associated Neurodegeneration (FAHN) [47], a rare autosomal recessive disease with an estimated prevalence lower than one in one million [69]. Here, FA2H is linked to fatty acid hydroxylase-associated neurodegeneration.