Cerebrotendinous xanthomatosis: a rare disorder with a rare presentation

A young man was brought for mental retardation, frequent non-bloody diarrhoea and swellings at ankles and elbow. He became bed-ridden due to cataract, mental retardation and pain in the back and lower limb. There were repeated pathological fractures and vitamin D deficiency without renal dysfunction. There were low low-density lipoprotein and triglyceride levels. MRI of the brain revealed hypointense lesions in cerebellar white matter, heterogenous hyperintensity in dentate nucleus and adjacent white matter, right basal ganglia and in the periventricular region with diffuse cerebral atrophy. T1-weighted MRI (ankle region) revealed bilaterally thickened and irregular achilles tendons with hyperintense masses surrounded by patchy hypointensities. A similar xanthomatous lesion (cholestanol deposits) was also present in the sacral region. Vitamin D and calcium supplementation and chenodeoxycholic acid therapy improved pain at lower limbs and body weight. Cerebrotendinous xanthomatosis is a rare autosomal-recessive familial mutation of the sterol 27 hydroxylase causing lipid metabolic disease.