ESPE Abstracts

Objective: To explore the clinical manifestations and early identification of sitosterolemia.

Methods: To summarize the clinical characteristics of the case and review literatures of sitosterolemia.

Result: The child was an 11-year-old boy. The main complaint was that subcutaneous yellow nodules were found more than 1 years with blood cholesterol increased for 4 months. Two months ago, the patient came to the dermatology clinic. Subcutaneous nodule biopsy of the buttocks showed xanthomas. Family history: nothing special. Physical examination: BP: 99/57mmHg, BMI 14.2kg/m² (P5).Scattered xanthomas were found which are yellow-brown, soft, round or oval, clear border with the diameter 0.3cm to 1.0cm on knee joints, buttocks and elbow joints with no tenderness, ulceration, rash or bleeding. Laboratory test: TC 9mmol/l, TG 0.67mmol/l, LDL-c 8.60mmol/l. Liver function were normal. OGTT, thyroid function and 8AM cortisol were normal. Blood MS/MS and urine GCMS were normal. Liver, heart color ultrasound were normal. Brain MRI and MRA were normal. Genetic testing showed a compound heterozygous mutation of the ABCG5 gene. The mutation c.751C> T is derived from the mother, while the mutation c.1528C> G is derived from the father. So the diagnosis was confirmed. Treatment includs two aspects: one is diet control, and the other is medicine Diet Control: Both cholesterol and plant sterols in the diet need to be strictly controlled. Plant sterol-rich foods include vegetable oils, wheat germ, nuts, seeds, and avocados. However, it is not possible to have a completely plant sterols-free diet because they are present in almost every plant food and a low plant sterol diet can only reduce plasma sterol levels by about 30%. Therefore ezetimibe (5mg qd) was described to the patient. After 9 months of treatment, the child’s xanthomas gradually subsided and TC decrease to 5.17 mmol/l, and LDL-c decreased to 3.45 mmol/l without any side effect.

Conclusion: The clinical manifestation of sitosterolemia was mainly xanthomas. From this point, it is sometimes difficult to identify from other disease. However, when dyslipidemia is not particularly high, xanthomas have already appeared which may imply the diagnosis of sitosterolemia. Once familial hypercholesterolemia occurs, low-density lipoprotein will be very high; Cerebrontenantous xanthomatosis generally shows xanthomas, but blood lipids is not high; Wolman disease: this disease is rare in children. It is caused by an abnormal lysosomal acid lipase gene (LIPA) mutation with recessive inheritance. All of the above maybe give us some clinic clues to make a differential diagnosis.