Immunodeficiency, motor delay, and hypouricemia caused by a novel mutation of purine nucleoside phosphorylase gene in an Indian infant

Abstract

We describe an 11-month-old boy who presented with recurrent respiratory infections from 6 months of age. His elder sister died at 10 months with severe septicemia and meningitis. The boy had a mild motor delay. Investigations revealed T cell deficiency and very low serum uric acid suggestive of purine nucleoside phosphorylase (PNP) deficiency – a rare variant of severe combined immunodeficiency disease. A novel homozygous missense mutation of c.597C>G(p. S199R) of exon 5 on PNP gene confirmed the diagnosis. We suggest that uric acid should be a part of investigation profile for unidentified motor delay, as recurrent infections can be late presentation.

Keywords

• Adenosine deaminase deficiency
• hypouricemia
• purine nucleoside phosphorylase deficiency
• severe combined immunodeficiency