Rare Korean Cases of very-long-chain Acyl-CoA dehydrogenase deficiency with a novel recurrent mutation

Very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD; OMIM#201475) is a rare metabolic disorder of mitochondrial fatty acid oxidation. VLCADD includes three clinical forms that are grouped based on disease severity. Here, we present two unrelated patients suspected of having VLCADD based on a newborn screening test. One patient was diagnosed in the neonatal period and, to date, has not shown any symptoms or signs associated with VLCADD; in contrast, diagnosis was delayed in the other patient after events of hypoketotic hypoglycemia and steatohepatitis. Repeated biochemical analyses and a liver biopsy implied VLCADD, and direct sequencing analysis led to the discovery of three novel mutations, including an identical missense variant (p.Ser207Pro) on ACADVL. Our patients were the first cases of the milder form of VLCADD, and the identical mutation detected might represent a founder mutation in the Korean population and be associated with the milder phenotype of VLCADD.