Cerebrotendinous xanthomatosis is a fat (lipid) storage disorder that affects many areas of the body. People with this disorder cannot break down certain lipids effectively, specifically different forms of cholesterol, so these fats accumulate in various areas of the body. Xanthomatosis refers to the formation of fatty yellow nodules (xanthomas). Cerebrotendinous refers to the typical locations of the xanthomas (cerebro- meaning the brain and -tendinous meaning connective tissue called tendons that attach muscle to bone).
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.