Clinical and molecular characteristics of 35 Chinese children with Wiskott-Aldrich syndrome.

Background: Wiskott-Aldrich syndrome (WAS) is a rare primary immunodeficiency disease, with an incidence of 4/1,000,000 live male births. In China, an estimated number of 35 babies with WAS are born each year, but likely many remain undiagnosed.
Objectives: The objectives of study were to review the clinical and molecular characteristics of a cohort of Chinese children with WAS and to describe the long-term outcome of those who underwent hematopoietic stem cell transplant (HSCT).
Materials and Method: Records of 35 patients diagnosed with WAS during 1991-2008 were reviewed. Genetic diagnosis was established by direct gene sequencing.
Results: All patients had classical WAS phenotype. WASP mutations were identified in 33 patients from 29 families. Nine patients underwent HSCT at a mean age of 22.1 months (match-unrelated donor, n = 5; mismatched related donor, n = 2; matched-sibling donor, n = 2). Post-transplant immune hemolytic anemia and thrombocytopenia occurred in three patients with complete resolution. All patients survived without significant long-term complications and had full platelet, T and B lymphocyte recovery within 2 years post-transplant.
Conclusion: In the past decade, there has been significant improvement in clinical and genetic diagnosis of WAS in Chinese. We demonstrated excellent long-term survival in patients who underwent HSCT. Early workup for transplant should be advocated for children with classical WAS before they suffer from major disease complications and morbidities.