Affective Disorder as the First Manifestation of Methylmalonic Acidemia: A Case Report

Methylmalonic acidemia (MMA) is the most common organic acidemia in Asian cases. We report a 14-year-old boy who was admitted to psychiatric clinic with affective symptoms. MMA was diagnosed after extensive laboratory tests. This emphasizes that even a typical psychiatric disorder can actually represent part of the spectrum of an underlying systemic disorder. MMA is an autosomal-recessive inborn error of metabolism. The incidence might be as high as 1 in 25,000[1]. It is believed that this disease is more prevalent in the Middle East because of consanguineous marriages[2]. MMA usually presents clinically with nonspecific symptoms such as seizure, poor feeding, loss of consciousness, psychomotor retardation. As a consequence, patients often undergo extensive work-up before the correct diagnosis is made[3, 4]. MMA is usually diagnosed in the first year of life[2], however, this report deals with a patient whose disease could not be diagnosed until the age fourteen. H. is a 14-year-old male who was referred to child and adolescent psychiatry clinic without previous psychiatric history.