COMPARATIVE FREQUENCY AND SEVERITY OF HYPOGLYCEMIA IN SELECTED ORGANIC ACIDEMIAS, BRANCHED-CHAIN AMINO ACIDEMIA, AND DISORDERS OF FRUCTOSE METABOLISM

The Institution's experience with hypoglycemia in different types of o rganic acidemias, branched chain amino acidemia (MSUD), and disorders of fructose metabolism was reviewed retrospectively. The charts of 144 patients who were followed for 1-5 years were studied for the severit y and frequency of hypoglycemia. The patients were mainly Saudi; howev er, 10-25% were from neighboring countries. Therefore, the observation s pertain to the genetic groups in the Arabian peninsula. Organic acid emias which primarily manifest with neurologic signs, such as 4-hydrox ybutyric aciduria, infantile onset 3-methylglutaconic aciduria, and gl utaric aciduria type 1 never showed hypoglycemia. Patients with beta-k etothiolase deficiency, biotinidase deficiency, or intermittent or int ermediate MSUD, also did not have hypoglycemia during metabolic crisis . Hypoglycemia was rare and mild among neonates with classic MSUD, eth ylmalonic aciduria, and isovaleric acidemia. Less than 50% of the pati ents with MSUD older than 8 months, pyruvate carboxylase deficiency, m ethylmalonic acidemia, or propionic acidemia had hypoglycemia during m etabolic crisis. On the other hand, patients with 3-hydroxy-3-methyl g lutaryl-CoA lyase deficiency, holocarboxylase synthetase deficiency, m edium or long-chain acyl-CoA dehydrogenase deficiency, neonatal onset 3-methylglutaconic aciduria, glutaric aciduria type 2, and disorders o f fructose metabolism invariably had moderate-to-severe hypoglycemia a ssociated with metabolic crisis. The purpose of this report is to prov ide the pediatrician, particularly in the Middle East, with a diagnost ic guideline to the identification and management of different types o f organic acidemias, based on co-existing hypoglycemia.