Cerebrotendinous Xanthomatosis Disease Prevalence in Patients with Autism Spectrum Disorder: A Prospective Observational Study.

Background: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive congenital metabolic disorder, which is characterized by the impairment of the enzymatic activity of sterol 27-hydroxylase. CTX, a rare neurodegenerative disease of sterol metabolism, can affect multiple systems, including the nervous system. It has been demonstrated that many congenital metabolic diseases like CTX are associated with autism spectrum disorder (ASD). The aim of this study was to identify the prevalence of CTX disease in patients with ASD.

Method: The clinical conditions of all patients were evaluated using the Mignarri Scoring Index. A sociodemographic form and Gilliam Autism Rating Scale-2 were applied to all participants.

Results: In total, 101 children and adolescents with ASD were analyzed for genes. Following genetic analyses, 4 patients with mutations in the CYP27A1 gene, two homozygous variants, and two different heterozygous mutations were identified. Most common symptom was diarrhea. Overall, 67.3% of all patients and 3 in 4 cases with CYP27A1 gene mutation had gone through psychiatric evaluation. A family history of a psychiatric disorder was present in 19.8% of all cases and in 75% of cases with mutations. Moreover, all mutant cases had comorbid oppositional defiant disorder. A total of 81.2% of all patients and all mutant patients were diagnosed with a behavioral disorder.

Conclusion: Psychiatric manifestations ranging from personality changes to behavioral disorders might accompany CTX. Better understanding and knowledge of the CTX disease by distinguishing specific psychiatric and systemic symptoms might help prevent missed diagnoses, progressive neurological deterioration, and permanent disability through early initiation of chenodeoxycholic acid treatment.