<unk> , often called PNP-deficiency, is a rare congenital immunodeficiency of<unk><unk><unk> . This enzyme is important in the<unk>  degradation pathway. A deficiency of it causes T-cell immunodeficiency. It is also often associated with neurological disorders such as mental retardation. This autosomal recessive metabolic disorder results in severe combined immunodeficiency.
Purine nucleoside phosphorylase deficiency
Triosephosphate isomerase deficiency
Pyridoxamine 5-prime-phosphate oxidase deficiency
Carbamoyl phosphate synthetase I deficiency
Pyruvate kinase deficiency
Alpha-ketoglutarate dehydrogenase deficiency
Ornithine translocase deficiency
Fumarase deficiency