Progressive ataxia of cerebrotendinous xanthomatosis with a rare c.255+1G>T splice site mutation: A case report

BACKGROUND: Cerebrotendinous xanthomatosis is an autosomal recessive disorder of lipid metabolism caused by the mutation of the CYP27A1 gene encoding sterol 27-hydroxylase, an essential enzyme for the conversion of cholesterol to chenodeoxycholic and cholic acids. Cerebrotendinous xanthomatosis is a rare neurological disease with a wide range of clinical symptoms that are easily misdiagnosed. CASE SUMMARY: Here we report the clinical, biochemical, and molecular characterization of a 33-year-old female patient with cerebrotendinous xanthomatosis. The patient developed ataxia and had the typical symptoms of juvenile cataracts, tendon xanthomata, and progressive nervous system dysfunction. Magnetic resonance imaging of the brain revealed bilateral dentate nucleus lesions and white matter abnormalities. This patient was misdiagnosed for 2 years resulting in severe neurological complications. After 2 years of chenodeoxycholic acid treatment, she still presented with ataxia and dysarthria. The pathogenic sites of CYP27A1 were identified as c.255+1G>T and c.1263+1G>T, which were both caused by shear denaturation. CONCLUSION: Cerebrotendinous xanthomatosis requires a multidisciplinary diagnosis that must be made early to avoid progressive neurological degeneration. c.1263+1G>T is a known mutation, but c.255+1G>T is a rare mutation site.