A Novel Mutation In Fanconi Bickel Syndrome Diagnosed In The Neonatal Period

Fanconi Bickel Syndrome (FBS), also known as glycogen storage disease type XI, is a rare autosomal recessive disorder. This syndrome has many different identified mutations and it is rare to be diagnosed during the neonatal period. Our patient is a two-weeks old female newborn who was admitted to our hospital with fever and dehydration. Renal Fanconi Syndrome was diagnosed in the presence of polyuria, proteinuria, glycosuria, hyperchloremic metabolic acidosis with normal anion gap and positive urine anion gap, hypourisemia, hypophosphatemia and increased excretion of phosphorus in urine. A novel mutation, IVS8 homozigot g.24401-24406del6 in the GLUT2 gene was demonstrated by Sanger method. The same mutation was detected as heterozygote in her parents. Although most of the affected infants have a consanguineous parentage history in the literature, our patient was born to a non-consanguineous parents. The interest of our FBS case lies in the timing of diagnosis which happened in the patient’s first month of life as only a few cases of FBS are recognized in this period as well as having a novel mutation in the literature.