Nail-patella syndrome and IgA nephropathy in a Chinese woman

Nail-patella syndrome (NPS), also known as hereditary onycho-osteodysplasia, is an autosomal dominant pleiotropic disorder characterized by nailbed dysplasia or hypoplasia, absent or hypoplastic patellae, iliac horns and deformation or luxation of the radial head. Nephropathy is a known serious complication associated with NPS. In this report, we describe an adult Chinese woman with the clinical and radiological features of NPS who presented with the nephrotic syndrome. Renal biopsy disclosed focal segmental glomerulosclerosis on light microscopy, while immunofluorescence revealed predominant staining for IgA in the glomerular mesangium and along some capillary walls. Ultrastructural study confirmed the presence of paramesangial deposits as well as subendothelial collagen fibrils in the glomeruli. The histological findings were those of combined NPS and IgA disease, an association which has rarely been described.