D-bifunctional protein deficiency, a peroxisomal fatty acid oxidation disorder leads to severe biochemical abnormalities.
Infants with this disorder exhibit poor muscle tone, seizures, altered brain structure, vision and hearing impairment, and profound developmental delays, often experiencing seizures shortly after birth. The condition, the most severe among peroxisomal disorders, is usually fatal within the first two years of life. Affected children may also have liver enlargement and distinct facial features. Few infants with D-bifunctional protein deficiency achieve any developmental milestones due to the severe impact on their neurological and physical health. Unfortunately, there is no treatment for this disorder.
D-bifunctional protein deficiency is caused by pathogenic (disease-causing) variants in the HSD17B4 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background.
Other names for this condition are 17-beta-hydroxysteroid dehydrogenase IV deficiency, bifunctional peroxisomal enzyme deficiency, DBP deficiency, PBFE deficiency, peroxisomal bifunctional enzyme deficiency, pseudo-Zellweger syndrome, and Zellweger-like syndrome.