D-bifunctional protein deficiency (DBPD)

Epidemiology

rare

Pathology

• polymicrogyria
• fontanels large
• replacement of the entire adrenal cortex with a single type of lipid-containing 'balloon' cell

Genetics

• caused by defects in HSD17B4 gene

Clinical manifestations

• neonatal adrenoleukodystrophy
• hypotonia & macrocephaly at birth
• development of seizures
• post-natal ventilatory support
• necrotizing enterocolitis
• death in 1st year of life

Laboratory

• HSD17B4 gene mutation

Diagnostic procedures

• normal levels of serum phytanic acid and L-pipecolic acid
• normal plasmalogen synthesis in cultured fibroblasts
• electron microscopy:
  • peroxisomes are present in tissues
• immunoblot studies of peroxisomal beta-oxidation enzymes shows deficiency of HSD17B4
• mRNA coding for the bifunctional enzyme present in fibroblasts
• EEG abnormalities
• brain biopsy

More general terms

• enzyme deficiency

Database

• OMIM: https://mirror.omim.org/entry/261515