169: SITOSTEROLEMIA PRESENTING WITH SEVERE HYPERTENSION AND CONGESTIVE HEART FAILURE IN A CHILD

Abstract

Introduction: Sitosterolemia is an autosomal recessive condition caused by pathogenic variants in the ABCG5/ABCG8 genes that prohibit the body from excreting plant sterols, causing build-up in the soft tissues and systemic vasculature. Pediatric vasculopathy secondary to sitosterolemia is poorly described, and there is no clear guidance on the management of complications, including cardiac dysfunction. This case report describes the diagnosis and acute management of a child with severe systemic hypertension, multiple levels of arterial stenosis, and cardiomyopathy presenting in congestive heart failure and ultimately diagnosed with sitosterolemia. Description: An 8-year-old Amish male with no past medical history presented to the emergency department with emesis and associated fatigue and abdominal pain. Vital signs were significant for severe systemic hypertension (BP 220/110), a gallop rhythm, hepatomegaly, cardiomegaly, and mid-aortic narrowing on CT angiogram. Exam was also notable for bilateral knee xanthomas. Laboratory data after admission to the pediatric cardiac ICU showed elevated BNP (peak 4418 pg/mL) and total cholesterol (317 mg/dL) levels. Echocardiogram showed severe mitral and tricuspid valve regurgitation, severely dilated and concentrically hypertrophied and dysfunctional left ventricle, ejection fraction of 30%, and pulmonary hypertension. Consultations included genetics, cardiology, nephrology, and vascular surgery. Initial management included a continuous Milrinone infusion and loop diuretics with improved BP and congestive heart failure symptoms. Cardiac catheterization including coronary and renal angiograms demonstrated severe proximal right coronary artery stenosis and bilateral renal artery stenosis. Right coronary artery and left renal artery angioplasties were performed with good results, and showed significant improvement in parameters of ventricular function and pulmonary arterial hypertension. Genetic testing and positive serum plant sterols confirmed the diagnosis of sitosterolemia. Discussion: Sitosterolemia is a rare genetic disorder and a rare cause of pediatric arteriopathy. Early recognition can prevent the development of life-threatening systemic hypertension, arterial stenosis including coronary artery disease, and cardiomyopathy.