Glycogen storage disease type 1b: an early onset severe phenotype associated with a novel mutation (IVS4) in the glucose 6-phosphate translocase (SLC37A4) gene in a Turkish patient.

Glycogen storage disease type I (GSD-I) is a group of autosomal recessive disorders that include types Ia and Ib. GSD-Ib is caused by a deficiency in the glucose-6-phosphate transporter (G6PT) caused by a mutation in the SLC37A4 gene coding for G6PT. Glycogen storage disease is characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver and chronic neutropenia. Herein we describe a 4-month-old Turkish patient with early onset and severe typical clinical features of GSD-1b in which a novel mutation in the SLC37A4 gene was detected. After the bone marrow examination parenteral antibiotic therapy and subcutaneous granulocyte colony-stimulating factor (G-CSF) were started. Due to the severe neutropenia the patient had developed nosocomial sepsis and the dose of G-CSF was increased. After 2 months later from the initial treatment of the G-CSF he developed splenomegaly and urinary complications. Despite maximal therapy he had an extremely poor quality of life and life-threatening complications due to impaired bone marrow function. As the patient required continual hospitalization he was schedule for bone marrow transplantation.