D-Bifunctional Protein Deficiency
Summary
D-bifunctional protein deficiency is a peroxisomal fatty acid oxidation disorder. The HSD17B4 enzyme is essential for breaking down very-long-chain fatty acids and bile acid intermediates in peroxisomes. Deficiency causes accumulation of these substances, damaging the brain and other organs.
Practical takeaway
Given the rarity of this condition, the probability of your partner also being a carrier is very low unless there is consanguinity or shared ancestry. Carrier testing is available if desired. Realised does not calculate reproductive risk or advise on reproductive decisions.
Evidence detail
What Carrier Status Means For You
You are not affected. One working copy of HSD17B4 is sufficient. Standard 25/50/25 recessive inheritance applies if your partner is also a carrier.
Population Context
DBP deficiency occurs across all populations without dramatic population-specific enrichment. Approximately 100-150 cases have been reported in the literature. It is one of the rarer peroxisomal disorders.
Limitations
23andMe tests 2 of many known pathogenic HSD17B4 variants. Coverage is minimal. Clinical sequencing is recommended if a partner is a known carrier.