Neurologic Status of Patients with Purine Nucleoside Phosphorylase Deficiency Before and After Hematopoetic Stem Cell Transplantation.

Background: Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive combined immunodeficiency. The phenotype is profound T cell deficiency with variable B and NK cell functions and results in recurrent and persistent infections that typically begin in the first year of life. Neurologic findings occur in approximately two-thirds of patients.