Iiopathic bilateral cataracts occur in many children with Cerebrotendinous Xanthomatosis (CTX) so the opportunity to use contact with health care providers in connection with pediatric cataract evaluation and treatment is a promising avenue for disease detection and prevention.

This is an observational, multicenter study to determine the prevalence of Cerebrotendinous Xanthomatosis (CTX) in patient populations diagnosed with early-onset idiopathic bilateral cataracts. Patients who are potentially eligible for study participation will be identified through a chart review of patients who were seen at each study site prior to that site's initiation, or by entering care at the site while the site is participating in the trial.

Inclusion Criteria:

1. The patient has a diagnosis of idiopathic bilateral cataracts
2. Between the ages of 2 to 21 years at the time of diagnosis

Exclusion Criteria:

1. The patient has a diagnosis of cataracts with known etiology other than CTX
2. The patient has a diagnosis of CTX
3. The patient has cataracts caused by cataractogenic treatments
4. The patient has taken or is currently taking cholic acid or chenodeoxycholic acid
5. The patient has participated in an interventional clinical trial in the past 30 days
6. The patient and/or their parent/legal guardian, in the opinion of the Investigator, is unable to adhere to the requirements of the study

Early-Onset Idiopathic Bilateral Cataracts