Cerebrotendinous xanthomatosis (CTX): a clinical survey of the patient population in The Netherlands.

The clinical features and additional investigations of 20 Dutch patients suffering from cerebrotendinous xanthomatosis (CTX), an inborn error of metabolism in bile acid synthesis, are described. The onset was in the second or third decade. The clinical picture at the time of examination consisted of a combination of two or more of the following signs: cataract, xanthoma of a tendon, mental deterioration, pyramidal tract signs, cerebellar signs and epilepsy. Mental retardation was reported in patients. CT-scanning showed cerebellar hypodensity in 8 out of 16 patients but this feature did not correlate well with cerebellar signs. The EEG was abnormal in all but one patient. Treatment with chenodeoxycholic acid resulted in a normalization of EEG and biochemical abnormalities but not of the clinical signs. Cholic acid was equally effective but had much less side effects. The importance of a diagnosis in early life is stressed as well as the examination of clinically unaffected heterozygous relatives.