An Observational Study for Evaluation of for the Prevalence of Cerebrotendinous Xanthomatosis (CTX) Disease

Inclusion Criteria: I-1. Giving written informed consent I-2. Patients in neurology clinics should have been identified with at least two of the following: * Ataxia and / or spasticity * Bilateral cataract (except senile cataract) * Intellectual limitation * Nonintensitive hyperintensity in T2 sections on MRI of the dentate nucleus * Forming an autosomal recessive transition pattern. (Ex: Relative Marriage) I-3. In the pediatric metabolism centers, cases suspected of CTX and planned to apply the Mignarri Index according to the investigator's opinion. I-4. On the day the patient signed the Informed Consent Form, the patient did not get older than 41 years of age (subjects aged 40 and under will be included in the study) Exclusion Criteria: E-1. The patient's ataxia and / or spasticity, cataract, intellectual limitation, and non-contrasted hyperintensity of T2 sections in MR imaging of dentate nuclei with typical MRI findings are due to a known cause other than CTX or other underlying disease. E-2. The patient has participated in an interventional clinical study in the last 30 days, E-3. The patient and / or his / her legal representative does not give consent to participate in the study, E-4. In the opinion of the investigator, the patient is not able to fulfill the working requirements appropriately, E-5. Pregnancy and / or lactation E-6. If the patient was 41 years old when included in the study.