Late Diagnosis of Fanconi-Bickel Syndrome: Challenges With the Diagnosis and Literature Review

ABSTRACT

Abstract Fanconi-Bickel syndrome (FBS), also known as glycogen storage disease type XI (GSD XI), is a rare autosomal recessive disorder of carbohydrate metabolism. It is caused by mutations in the gene SLC2A2, which encodes for the facilitative glucose transporter GLUT2. Diagnosis of FBS is often delayed since the clinical features and laboratory markers often overlap with other disorders whose characteristic features include short stature, fasting hypoglycemia, postprandial hyperglycemia, hepatomegaly, hypophosphatemic rickets, and proximal renal tubular dysfunction. In this article, we present a case of FBS and its management in an African American female who initially presented with persistent proximal tubulopathy, hypercalciuria, and metabolic acidosis. We also include a recent literature review on FBS and discuss other metabolic disorders that should be considered in the differential diagnosis.