Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive primary immunodeficiency disorder characterized by decreased numbers of T-cells, variable B-cell abnormalities, decreased amount of serum uric acid and PNP enzyme activity. The affected patients usually present with recurrent infections, neurological dysfunction and autoimmune phenomena. In this study, whole-exome sequencing was used to detect mutation in the case suspected of having primary immunodeficiency. We found a homozygous mutation in PNP gene in a girl who is the third case from the national Iranian registry. She had combined immunodeficiency, autoimmune hemolytic anemia and a history of recurrent infections. She developed no neurological dysfunction. She died at the age of 11 after a severe chicken pox infection. PNP deficiency should be considered in late-onset children with recurrent infections, autoimmune disorders without typical neurologic impairment.
Keywords: IgA deficiency; Purine nucleoside phosphorylase deficiency; autoimmune hemolytic anemia; chicken pox; combined immunodeficiency.