CblC‐Type Methylmalonic Acidemia Presenting as Macrocytic Anemia Mimicking Congenital Dyserythropoietic Anemia

Methylmalonic acidemia (MMA) is a group of autosomal recessive disorders caused by defects in the methylmalonic acid metabolic pathway.Among them, the cblC type is the most common and represents a major form of intracellular cobalamin metabolism disorder [ 1 ].This disease is characterized by multisystem involvement, affecting the nervous system, cardiopulmonary system, kidneys, and hematopoietic system, with diverse clinical manifestations.Hematologic abnormalities may include anemia, leukopenia, thrombocytopenia, and megaloblastic changes in the bone marrow [ 1,2 ].