The spectrum of magnetic resonance findings in cerebrotendinous xanthomatosis: redefinition and evidence of new markers of disease progression

Never Late: Cerebrotendinous Xanthomatosis and Improvements in Neurocognitive Functions in an Adult Patient on Chenodeoxycholic Acid Treatment

Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disease due to biallelic pathogenic variants in CYP27A1. We report a newly diagnosed patient and the outcome of the chenodeoxycholic acid (CDCA) treatment. This is a 36-year-old male with progressive lower limb spasticity, learning difficulties, and early cataracts. He was diagnosed by targeted next generation sequencing panel for hereditary spastic paraparesis (c.379C>T; p.Arg127Trp and c.1072C>T; p.Gln358* in CYP27A1) with CTX at the age of 33 years. Brain and spine magnetic resonance imaging (MRI) revealed increased T2 signal intensity in the dentate nuclei and bilateral posterolateral spinal cord. Baseline plasma 7a-hydroxy-4-cholesten-3-one (> 5; ref. range < 0.300 nmol/mL) and 7a,12a dihydroxycholest-4-en-3-one (> 5; ref. range < 0.100 nmol/mL) were markedly elevated. Baseline full-scale IQ was 69. The CDCA treatment (750 mg/day) was started at the age of 34 years. Plasma 7a-hydroxy-4-cholesten-3-one level was normalized; plasma 7a,12a dihydroxycholest-4-en-3-one level was markedly improved (0.755 nmol/mL; ref. range < 0.1) and full-scale IQ improved to 83 at two years of the CDCA treatment. This patient highlights improvements in neurocognitive functions despite late diagnosis and late initiation of treatment and exemplifies the importance of diagnosing a treatable disease at any age to improve neurocognitive outcomes.

First case series of Polish patients with cerebrotendinous xanthomatosis and systematic review of cases from the 21st century

Cerebrotendinous xanthomatosis (CTX) is an inborn error of metabolism caused by recessive variants in the cytochrome P450 CYP27A1 gene. CTX is said to manifest with childhood-onset chronic diarrhea and the classic triad of juvenile-onset cataracts, Achilles tendons xanthomas, and progressive ataxia. It is currently one of the few inherited neurometabolic disorders amenable to a specific treatment. The diagnosis may be significantly delayed resulting in permanent neurological impairment. A retrospective review of the clinical characteristics and diagnostic findings in case series of six Polish patients with CTX. Additional retrospective review of symptoms and pathogenic variants of 568 CTX available cases and case series from the past 20 years. To the best of our knowledge, this is the widest review of CTX cases reported in years 2000-2021. We report the largest cohort of Polish patients ever published, with the identification of two hot-spot mutations. During the review of available 568 cases, we found significant differences in the clinical phenotypes and the localization of variants within the gene between Asian and non-Asian populations. These findings may facilitate molecular testing in the Polish and Asian populations. Invariably better screening for CTX and wider awareness is needed.