Lack of feasibility

This study is designed to demonstrate the beneficial effect of CDCA in the treatment of CTX-associated diarrhea in approximately 10 participants aged 2-75 years old with newly diagnosed CTX or suspected CTX who have never received treatment with CDCA.

Inclusion Criteria:

• Signed informed consent form (or assent form as appliable)
• Aged from 2 to 75 years old
• Has a new or suspected diagnosis of CTX as defined by an elevated plasma cholestanol concentration (>10 mg/L/>25.7 μmol/L) in conjunction with a clinical presentation consistent with the diseased as assessed by the investigator
• Has never received treatment with CDCA
• Has never received treatment with other bile acid products

Exclusion Criteria:

• Any medical condition that, in the opinion of the investigator, precludes the participant's participation in the study
• Presence of known hepatocyte dysfunction or bile ductal abnormalities such as intrahepatic cholestasis, primary biliary cirrhosis or sclerosing cholangitis
• Inability to adhere to treatment and visit schedule
• Female participants who are pregnant
• Female participants who are breast feeding
• Female participants who are using estrogen-containing compounds and cannot/will not discontinue them for the duration of the study
• Female participants of childbearing potential who are not using locally approved birth control method(s) or double barrier contraception (ie, condom and diaphragm, condom or diaphragm and spermicidal gel or foam)
• Taking any of the following medications: bile acid products; inhibitors of bile acid transporters; bile acid binding resins; aluminum-based antacids; coumarin and its derivatives; cholestyramine; ciclosporin; sirolimus; or phenobarbital