Prevalence of cerebrotendinous xanthomatosis in cases with idiopathic bilateral juvenile cataract in ophthalmology clinics in Turkey

PURPOSE To determine the prevalence of cerebrotendinous xanthomatosis (CTX) in patients with idiopathic bilateral juvenile cataract in Turkey. METHODS In this multicenter, epidemiologic observational study, patients with idiopathic bilateral juvenile cataract (aged ≥1 year at study entry) were identified from the records of 31 ophthalmology clinics. The Mignarri suspicion index was used to screen for potential CTX patients; blood samples were collected, and genetic testing for CYP27A1 gene mutation was performed. Cholestanol levels of the patients were measured, and those with a level of ≥3.75 μg/mL (threshold value) underwent genetic testing for mutations in the CYP27A1 gene. RESULTS CTX was diagnosed in 7 of 452 patients (1.55%) with bilateral juvenile cataract. There was no significant difference between patients with a Mignarri score of <100 (n = 8) and those with a score of ≥100 (n = 19) with respect to cholestanol levels and genetic test results. Genetic testing was undertaken in 27 patients based on elevated cholestanol levels. Of these 27, 7 (26%) had CYP27A1 gene mutations. Of these 7 patients with genetically confirmed CTX, 5 (71%) were in the group with higher Mignarri score (≥100). CONCLUSIONS CTX is a treatable condition, and early detection is crucial for avoiding irreversible neurological manifestations. Screening using the Mignarri suspicion index and cholestanol blood levels can be helpful in identifying suspected cases of CTX.