Novel HADHB mutations in a patient with mitochondrial trifunctional protein deficiency

We encountered a patient with mitochondrial trifunctional protein deficiency in whom the corresponding mutations were not identified by a DNA panel for newborn screening for targeted diseases. After diagnosis confirmation by an enzyme assay and immunoblotting using the autopsied liver, the re-evaluation of the panel data indicated a heterozygous deletion of exons 6–9 that was later confirmed at the genomic level. cDNA analysis also identified exonization of the 5′ region of intron 9 caused by a deep intronic mutation, c.811 + 82A>G.