Very long-chain acyl-CoA dehydrogenase (
VLCAD) deficiency is a disorder of
fatty acid beta-oxidation that can present at any age with
cardiomyopathy,
rhabdomyolysis, hepatic dysfunction, and/or nonketotic
hypoglycemia. Through the expansion of newborn screening programs an increasing number of individuals with
VLCAD deficiency are being identified prior to the onset of symptoms allowing early initiation of
therapy. The development of a safe, durable, and effective
VLCAD gene delivery system for use at the time of diagnosis could result in a significant improvement in the quality and duration of life for patients with
VLCAD deficiency. To this end, we developed a construct containing the human
VLCAD cDNA under the control of the strong CMV promoter (pCMV-hVLCAD). A novel rabbit polyclonal anti-
VLCAD antibody was prepared using a 24
amino-acid peptide unique to the human
VLCAD protein to study human
VLCAD expression in immune competent mice. Antibody specificity was demonstrated in Western blots of human
VLCAD deficient fibroblasts and in pCMV-hVLCAD transiently transfected
VLCAD deficient fibroblasts. Transfected fibroblasts showed correction of the metabolic block as demonstrated by normalization of C14- and C16-acylcarnitine species in cell
culture media and restoration of
VLCAD activity in cells. Following tail vein injection of pCMV-hVLCAD into mice, we demonstrated expression of hVLCAD in liver. Altogether, these steps are important in the development of a durable gene therapy for
VLCAD deficiency.