Fanconi-Bickel syndrome is an extremely rare hereditary
metabolic disease, characterized by
hepatomegaly due to
glycogen storage, refractory
hypophosphatemic rickets, marked growth retardation and
proximal renal tubular acidosis. Recurrent
bone fractures are one of the hallmark findings. It is a single gene disorder; the responsible gene belongs to the facilitative
glucose transporters 2 (GLUT2) family gene or (SLC2A2) mapped to the q26.1-26.3 locus on chromosome 3, and encodes the GLUT
protein 2. This
protein is expressed in pancreatic ί-cells, hepatocytes, renal tubules, and intestinal mucosa. Several mutations in the GLUT2 gene have been reported in different ethnicities. Herein we report an Iranian girl with a missed diagnosis of
osteogenesis imperfecta. She was referred with the history of frequent fractures, and severe motor delay and was suspected to
osteogenesis imperfecta. Following the case we detected refractory
rickets instead of OI, sever growth failure, proximal renal tubulopathy and RTA, and enlarged kidneys, progressive
hepatomegaly, and GSD on liver biopsy.
Glucose and
galactose tolerance tests confirmed abnormal carbohydrate metabolism. Molecular analysis on GLUT2 gene revealed a homozygous novel mutation in exon 5; it was 15
nucleotide deletion and 7
nucleotide insertion and caused a frame shift mutation, produced a premature truncated
protein (P.A229QFsX19). This mutation has not been reported before in the relevant literature.