Isobutyryl-CoA dehydrogenase deficiency with a novel ACAD8 gene mutation detected by tandem mass spectrometry newborn screening

Isobutyryl-CoA dehydrogenase (IBD) is an enzyme involved in the catabolism of the branched-chain amino acid valine. IBD deficiency is a very rare metabolic disorder, whereby only a few cases have been reported thus far. Recently, we observed a Korean newborn boy with elevated concentration of C4-acylcarnitine detected by tandem mass spectrometry neonatal screening. Subsequent sequencing analysis of ACAD8 gene revealed that he was compound heterozygous for a novel mutation involving the first codon (c.3G>T; Met1Ile) and a previously reported mutation (c.1000C>T; Arg334Cys). To the best of our knowledge, this is the first confirmed case of IBD deficiency based on biochemical and genetic studies not only in Korea but also in Asia.