[Cerebrotendinous xanthomatosis: report of 4 patients].

Cerebrotendinous xanthomatosis (CTX) is an uncommon autosomal recessive disease caused by mutation of the CYP27A1 gene. It is characterized by the presence of xanthomas in different tissues, principally brain and tendon, due to the accumulation of beta-cholestanol. Diagnosis is confirmed by measurement of serum beta-cholestanol and urinary bile alcohol levels. Therapy with chenodeoxycholic acid has been shown to be the most effective treatment and can halt progression of the disease. We present 4 patients with a history of neurological disorders since childhood and who were diagnosed with CTX after developing tendon xanthomas. Although diagnostic suspicion depends to a large extent on recognition of tendon xanthomas, these are not an early sign of the disease, which can present with neurological disorders, cataracts, and chronic diarrhea. Early diagnosis of CTX therefore rests on measurement of serum beta-cholestanol levels, even in absence of tendon xanthomas.