von Willebrand Disease in Children with Glycogen Storage Disease Type Ia.

Glycogen storage disease, Type Ia (GSD-Ia) is an autosomal recessive disease, characterized by hepatomegaly, hypoglycemia, hyperuricemia, and bleeding diathesis. Easy bruising and epistaxis are common and are associated with a prolonged bleeding time as a result of impaired platelet aggregation and adhesion. Two of four of our GSD-Ia patients were evaluated because of bleeding diathesis and both were diagnosed as von Willebrand’s disease (vWd) with normal platelet count, prothrombin time and activated partial thromboplastin time.

Case 1: Six year old boy diagnosed as GSD-Ia when he was 3 month of age and bleeding diathesis was first recognized 5^th year of his life. His bleeding time was prolonged (15 minutes). Measurement of serum factor VIII-related antigen (vWf-Ag) revealed a decrease (% 31) and ristocetin cofactor activity was abnormal (% 37).

Case 2: Nine year old girl diagnosed as GSD-Ia when he was 6 month of age and bleeding diathesis was first recognized 4^th year of his life. His bleeding time was prolonged (3.5 minutes). Measurement of serum factor VIII-related antigen (vWf-Ag) revealed a decrease (% 17) and ristocetin cofactor activity was abnormal (% 5.7).

Frequent diagnosis of vWd among our GSD-Ia patients might suggest alterations in membrane glycoprotein synthesis. There is no definitive explanation addresses how these alterations actually cause defective platelet aggregation. Although, the presence of association between these two separate diseases might be coincidental, in literature, diagnosis of vWd among GSD-Ia patients had been reported in only one paper. We conclude that GSD-Ia patients may have a metabolically acquired form of vWd as well as an acquired intrinsic platelet defect. Further molecular studies may be necessary to clarify the etiopathogenesis of this association.