Skip navigation

What is D-Bifunctional Protein Deficiency?

D-Bifunctional Protein Deficiency is an autosomal recessive disorder in which the body cannot break down certain building blocks of fat called ‘fatty acids’.  This leads to the buildup of fatty acids in the blood and organs that then cause damage to many parts of the body, especially the brain and nervous system.  Signs and symptoms begin in infancy and include large head size, distinct facial features, feeding problems, poor muscle tone, vision and hearing loss, liver and kidney disease, seizures, severe developmental delay, and bone abnormalities.  There is no cure for this disorder and death usually occurs before two years of age.  Rarely, a child with this condition may start having symptoms at a later age leading to loss of skills and death later in childhood.

Very rarely, mutations in the same gene cause a different disorder called Perrault Syndrome.  Symptoms of Perrault Syndrome include hearing loss starting at birth or early childhood that worsens over time and, in females, missing or non-working ovaries with infertility. Some people with this condition also have learning difficulties, problems with coordination and walking, and loss of sensation in the arms and legs. 

What causes D-Bifunctional Protein Deficiency?

D-Bifunctional Protein Deficiency is caused by a gene change, or mutation, in both copies of the HSD17B4 gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

icon-angle icon-bars icon-times