Four mutation types of the MMACHC gene (e.g., c.609G > A (p.Trp203Ter), c.567dupT (p.Ile190fs)) and six mutation types of the MMUT gene (e.g., c.729_730insT (p.Asp244fs)) were found for methylmalonic acidemia. The gene discussed is MMUT; the disease is methylmalonic acidemia.