DBP deficiency can be divided into three types: * type I, characterized by a deficiency in both the hydratase and dehydrogenase units of D-BP * type II, in which only the hydratase unit is non-functional * type III, with only a deficiency in the dehydrogenase unit Type I deficient patients showed a large structural modification to the D-BP as a whole. Most of these individuals showed either a deletion or an insertion resulting in a frameshift mutation. Type II and III patients showed small scale changes in the overall structure of D-BP6. Amino acid changes in the catalytic domains or those in contact with substrate or cofactors were the main cause of these variations of D-BP deficiency. Other amino acid changes were seen to alter the dimerization of the<unk> , leading to improper folding. Many mutations have been found in the gene coding for D-BP (HSD17B4) on the q arm two of chromosome five (5q23.1) in Homo sapiens, most notably individuals homozygous for a missense mutation (616S).
D-bifunctional protein deficiency
Glutaminase deficiency
Biotinidase deficiency
Aminoacylase 1 deficiency
Holocarboxylase synthetase deficiency
Ornithine aminotransferase deficiency
Arginine:glycine amidinotransferase deficiency
Multiple carboxylase deficiency