MITOCHONDRIAL SHORT-CHAIN L-3-HYDROXYACYL-COENZYME A DEHYDROGENASE-DEFICIENCY - A NEW DEFECT OF FATTY-ACID OXIDATION

We describe two children with deficiency of short-chain L-3-hydroxyacy l-CoA dehydrogenase, a new disorder of the mitochondrial beta-oxidatio n of straight-chain fatty acids. The patients presented with fasting-i nduced vomiting, and ketosis and low blood glucose, features typical o f ketotic hypoglycemia were documented in one. Enzyme assays were perf ormed in cultured skin fibroblasts. In whole fibroblast preparations t here was reduced enzyme activity but high residual activity due to the presence of a nonmitochondrial enzyme. In isolated fibroblast mitocho ndria the residual enzyme activities were 5 and 6% of the normal contr ols. Activity in an obligate heterozygote was inter mediate, suggestin g that this is an autosomal recessive disorder.