PHYTOSTEROLAEMIA IN A NORWEGIAN FAMILY - DIAGNOSIS AND CHARACTERIZATION OF THE FIRST SCANDINAVIAN CASE

Phytosterolaemia (sitosterolaemia) is a very rare inherited sterol sto rage disease characterized by tendon and tuberous xanthomas and by a p redisposition to atherosclerosis. We here describe the first Scandinav ian case. The 14-year-old female patient was found to have markedly el evated circulating levels of plant sterols (sitosterol, sitostanol, ca mpesterol, stigmasterol), and the levels of these sterols were 20-50 t imes higher than in her healthy sister and heterozygous parents. In ad dition to the usual serum plant sterols we found a new major sterol in the patient tentatively identified as episterol or fecosterol (24-met hylidencholest-7(or 8)-en-3 beta-ol). A newly developed method based o n the use of deuterium labelled cholesterol and plant sterols was used to measure sterol absorption in the patient and her relatives. Absorp tion of sitosterol averaged 20% in the patient and ranged from 4 to 8% in the relatives. Absorption of campesterol averaged 31% in the patie nt and ranged from 15 to 18% in her relatives. Absorption of cholester ol averaged 63% in the patient and ranged from 35 to 45% in the relati ves. Cholesterol synthesis appeared to be reduced in the patient and w as 46-52% of that of her relatives.