Differential diagnosis of a patient with lysosomal acid lipase deficiency: A case report

Background: We describe the differential diagnosis of an obese 12-year-old boy of Mexican origin who presented with a 6-year history of abnormal lipid profile and elevated liver transaminase levels. Methods: The patient underwent routine clinical testing, an abdominal ultrasound and, ultimately, a liver biopsy. Based on the histologic findings, a serum leukocyte lysosomal acid lipase (LAL) assay and DNA sequencing of the lipase A (LIPA) gene were performed. Results: Liver biopsy revealed diffuse microvesicular steatosis with clusters of foamy histiocytes in the lobules and portal areas. Our differential diagnosis included nonalcoholic fatty liver disease; medication-induced hepatotoxicity; glycogenic hepatopathy; medium-chain acyl coenzyme A dehydrogenase or long-chain acyl coenzyme A dehydrogenase deficiency; and lysosomal storage disorders, including Niemann-Pick disease and lysosomal acid lipase deficiency (LAL-D). Serum LAL activity was absent, and DNA sequencing confirmed homozygous mutation in LIPA. Conclusions: Although it occurs rarely, LAL-D should be considered in the differential diagnosis of microvesicular steatosis for a timely diagnosis.