Primary Pulmonary Hypertension Associated with Asymptomatic Methylmalonic Aciduria in a Child

Methylmalonic acidemia or aciduria (MMA) is an inborn error of metabolism that results in the accumulation of methylmalonic acid in blood with an increased excretion in urine. MMA usually presents in early infancy and its effects vary from mild to life-threatening. The clinical symptoms mainly include vomiting, dehydration, hypotonia, developmental delay, and failure to thrive. An association between pulmonary arterial hypertension (PAH) and MMA has been rarely reported. In the present work, the authors report a 16-month boy, who was admitted to the Pediatric Department for cyanosis and fever. He had a family history of primary pulmonary hypertension in a sister. The echocardiography showed a mild pericardial effusion and PAH. The metabolic screening led to the diagnosis of MMA. The condition of the baby worsened rapidly- and he died a few days later. Physicians should be aware about this atypical presentation of the disease, which can be fatal if not diagnosed and managed promptly.