<prompt> Deficiency of purine nucleoside phosphorylase causesComplement deficiencyCellular immunodeficeincyHumoral immunodeficeincyCombined immunodeficeincy  <response>: A combined T cell and B cell immunodeficiency that is a rare autosomal recessive metabolic disorder that has material basis in mutation in the PNP gene and characterized mainly by decreased T-cell function. Ref-Sathyanarayana 4e 