The most common organic acidemias in this group of patients was methylmalonic acidemia (MMA, 16, 59.3%), followed by 3-methylcrotonyl CoA carboxylase (3-MCC) deficiency (5, 18.5%), ethylmalonic encephalopathy (EE, 4, 14.8%) and β-ketothiolase deficiency (BKD, 1, 3.7%) (Table 4). Here, PPIB is linked to Merkel cell skin cancer.