SUMMARY
1. Glycogen storage disease (GSD) Ib is an autosomal recessive disease characterized by severe hypoglycemia, failure to thrive, and hepatomegaly. It is caused by a deficiency in the glucose-6-phosphate transporter.
2. Severe neutropenia occurs in 87% of patients with GSD Ib. Neutropenia is also common in patients with GSD Ic. Patients with GSD Ia do not have associated neutropenia. Neutrophil function may also be decreased.
3. Patients develop oral ulcers, perianal abscesses, and inflammatory bowel disease (likely due to defective neutrophil function).
4. Patients with significant neutropenia may benefit from treatment with G-CSF therapy. In some patients, G-CSF therapy resulted in increased neutrophil counts and decreased bowel inflammation.
OVERVIEW
Glycogen storage disease (GSD) Ib is an autosomal recessive disease characterized by severe hypoglycemia, failure to thrive, and hepatomegaly. It is caused by a deficiency in the glucose-6-phosphate transporter.
Severe neutropenia occurs in 87% of patients with GSD Ib. Neutropenia is also common in patients with GSD Ic. Patients with GSD Ia do not have associated neutropenia. Neutrophil function may also be decreased.
Patients develop oral ulcers, perianal abscesses, and inflammatory bowel disease (likely due to defective neutrophil function).
EVALUATION
Once a diagnosis of Glycogen storage disease Ib or Ic has been established, patients should have an immune evaluation.
Step 1: Immune Evaluation
-CBC with Differential
-DHR assay
-Significant neutropenia has been reported in GSD Ib/Ic.
-Decreased phagocyte function has also been reported in GSD.
MANAGEMENT
Patients with significant neutropenia may benefit from treatment with G-CSF therapy. In some patients, G-CSF therapy resulted in increased neutrophil counts and decreased bowel inflammation.