Bile Acid Synthesis Disorders in Japan: Long-Term Outcome and Chenodeoxycholic Acid Treatment

We encountered 7 Japanese patients with bile acid synthesis disorders (BASD) including 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase/isomerase (3β-HSD) deficiency (n = 3), Δ⁴-3-oxosteroid 5β-reductase (5β-reductase) deficiency (n = 3), and oxysterol 7α-hydroxylase deficiency (n = 1) over 21 years between 1996 and 2017.

We aimed to clarify long-term outcome in the 7 patients with BASD as well as long-term efficacy of chenodeoxycholic acid (CDCA) treatment in the 5 patients with 3β-HSD deficiency or 5β-reductase deficiency.

Diagnoses were made from bile acid and genetic analyses. Bile acid analysis in serum and urine was performed using gas chromatography-mass spectrometry. Clinical and laboratory findings and bile acid profiles at diagnosis and most recent visit were retrospectively obtained from medical records. Long-term outcome included follow-up duration, treatments, growth, education/employment, complications of treatment, and other problems.

Medians with ranges of current patient ages and duration of CDCA treatment are 10 years (8 to 43) and 10 years (8 to 21), respectively. All 7 patients, who had homozygous or compound heterozygous mutations in the HSD3B7, SRD5B1, or CYP7B1 gene, are currently in good health without liver dysfunction. In the 5 patients with CDCA treatment, hepatic function gradually improved following initiation. No adverse effects were noted.

We concluded that CDCA treatment is effective in 3β-HSD deficiency and 5β-reductase deficiency, as cholic acid has been in other countries. BASD carry a good prognosis following early diagnosis and initiation of long-term CDCA treatment.