Severe Anemia in Patients with Propionic Acidemia is Associated with Low Plasma Levels of Valine, Isoleucine and Methionine

Abstract

Background. Propionic acidemia (AP), an inborn error of metabolism, is caused by a deficiency in propionyl-CoA carboxylase. Patients have to follow a diet restricted in the propiogenic amino acids isoleucine (Iso), valine (Val), methionine (Met) and threonine (Thr); proper adherence can prevent and treat acute decompensation and increase life expectancy. However, chronic complications occur in several organs even though metabolic control may be largely maintained. Bone marrow aplasia and cytopenia are among the more common. Materials and methods. In this retrospective study, data for patients with PA being monitored at the Hospital Ramón y Cajal (Madrid, Spain) (n=10) were examined to statistically detect relationships between hematological complications outside of metabolic decompensation episodes, and plasma amino acids provided by the diet, urinary organic acids and plasma odd-chain fatty acids. High ferritin levels were deemed to indicate that a patient had received repeated transfusions for severe anemia since data on hemoglobin levels at the moment of transfusion were not always passed on by the attending centers. Results. Three patients had severe, persistent anemia that required repeated blood transfusions leading to high ferritin levels. Their low plasma Val, Ile and Met suggested that their anemia had a nutritional component. Conclusion. The present results suggest that severe anemia in patients with PA is associated with low plasma levels of Val, Ile and Met.