Resident, PGY-2 University of South Florida University of South Florida Saint Petersburg, Florida, United States
Background: Sitosterolemia is a rare autosomal recessive disorder with approximately 100 patients reported in the literature and no known cases in neonates. This disorder is characterized by mutations in ABCG5 or ABCG8 genes leading to elevated concentrations of plant sterols due to intestinal hyperabsorption and decreased biliary excretion. Clinical manifestations include xanthomas, accelerated atherosclerosis, premature coronary artery disease, hepatosplenomegaly and hematologic manifestations such as hemolytic anemia and thrombocytopenia.
Objective: We report a neonate with sitosterolemia who presented at birth with hepatosplenomegaly and subsequently developed severe liver failure. To our knowledge this is the first case of neonatal sitosterolemia.
Design/Methods: Case report
Results: This is a case of a full term male born to a primigravid mother with an unremarkable prenatal course, admitted to the NICU secondary to respiratory distress. He was noted to have hepatosplenomegaly and persistent hypoglycemia at birth. Within two days, he developed hemolytic anemia and thrombocytopenia requiring IVIG and multiple blood products for coagulopathy. His liver function quickly deteriorated and by week two, he had severe hyperbilirubinemia with maximum total bilirubin level of 35.3 mg/dL and a direct level of 26.6 mg/dL, treated with multiple exchange transfusions. An ultrasound guided liver biopsy reported severe cholestatic pattern of injury with bile duct plugging, pseudoacinar changes, mild steatosis, ballooning degeneration, extramedullary hematopoiesis and increased hepatocellular iron. Genetic work-up revealed two variants of uncertain significance in the ABCG5 gene. These genetic variants combined with his elevated cholesterol (400 mg/dL) and sterol levels (sitosterol 25 mg/L; ref <5) were suggestive of sitosterolemia. Given these results and worsening liver failure, dietary modifications were made to decrease intake of plant sterols at two months of age. Now at one-year of age, his liver function tests and blood counts have normalized. He is developmentally appropriate and growing well while continuing to follow a low plant sterol diet. Conclusion(s): We report a critically ill neonate whose extensive genetic and biochemical testing provided a diagnosis of sitosterolemia. This rare disorder has not previously been reported in the neonatal population and could therefore be underdiagnosed. Sitosterolemia should be suspected in a neonate with unexplained liver disease and abnormal hematologic findings.
Authors/Institutions: Natalia Pineros, University of South Florida, Tampa, Florida, United States; Erica Schultz, University of South Florida, Tampa, Florida, United States; Jaime Flores-Torres, University of South Florida, Tampa, Florida, United States; Kara Morgan, University of South Florida, Tampa, Florida, United States; Juan Rico, University of South Florida, Tampa, Florida, United States; Karen Wickline, University of South Florida, Tampa, Florida, United States; Sarah Sidhu, Tampa General Hospital, Tampa, Florida, United States; Kristin Spence, University of South Florida, Tampa, Florida, United States; Amarilis Sanchez-Valle, University of South Florida, Tampa, Florida, United States
