Fanconi-Bickel syndrome in a 3-year-old Indian boy with a novel mutation in the GLUT2 gene

Fanconi-Bickel syndrome is a rare autosomal recessive disorder characterized by hepatorenal glycogen accumulation, proximal renal tubular dysfunction and impaired utilization of glucose and galactose. Most cases have been reported from Europe, Japan, Turkey and the Mediterranean belt. We report a 3-year-old boy from southern India who presented with doll-like facies, florid rickets, massive hepatomegaly, growth retardation, renomegaly and laboratory evidence of proximal renal tubular dysfunction. Liver biopsy demonstrated evidence of glycogenosis. Direct sequencing of genomic DNA confirmed a diagnosis of Fanconi-Bickel syndrome, revealing a G-to-A substitution at position -1 of the splicing acceptor site in intron 1 of the GLUT2 gene in a homozygous pattern (c. 16-1G>A or IVS1-1G>A). This novel mutation has not been described in earlier studies. The child was treated with oral potassium citrate, oral phosphorus supplementation, and alpha-calcitriol, on which metabolic derangements were corrected.