Effectiveness of Cholic acid treatment in Cerebrotendinous Xanthomatosis

Background: Cerebrotendinous Xanthomatosis (OMIM # 213700) is an autosomal recessive disorder of bile acids synthesis characterised by the development of bilateral cataracts, tendon xanthomas, chronic diarrhoea during childhood and progressive neurological deterioration which may include cognitive decline and motor disorders. The current treatment for CTX is chenodeoxycholic acid (CDCA) but it is not easily available in India. Some reports have also suggested the potential efficacy of cholic acid (CA) alone in patients with CTX. Herein, we present a case of CTX treated with cholic acid and report its effects.

Case study: The patient presented with symptoms of cataracts, ataxia and inability to walk, frequent loose motions, poor weight gain and biochemically, increased levels of cholestanol. The CTX diagnosis was genetically confirmed by a homozygous frameshift truncation pathogenic variant: c.526del; p.Asp176Metfs*6; rs765512351 in the CYP27A1 gene. Cholic acid treatment was initiated at a dose of 100 mg/day, increased to 200 mg/day after 3 months it was escalated to.

Results: Cholic acid was tolerated well and there was a significant reduction in loose motions and improvement in ataxia, vision and motor activities with a weight gain of 4 kg in 6 months (21 kg to 25kg). Biochemically, cholestanol levels reduced from 14.49 µmol/L to 6.07 µmol within 3 months, then to 3.58 µmol/L in the following 3 months. As there was an increase in cholesterol levels after 3 months of treatment, the patient was prescribed Rosuvastatin at a dose of 5 mg/daily.

Conclusion: Cholic acid is a suitable and economical alternative CTX treatment if CDCA is not readily available.