HMGCS2 and hyperinsulinemic hypoglycemia, familial, 4: Pathogenic variants of HMGCS2 have been associated with a rare autosomal recessive disorder of ketogenesis, namely HMGCS2 deficiency (OMIM#605911), which is characterized by hypoketotic hypoglycemia, metabolic acidosis, hepatomegaly, and encephalopathy, usually precipitated by intercurrent illness and/or prolonged fasting [1].