The nephropathy of the nail-patella syndrome. Clinicopathologic analysis of 11 kindred

Seventy-two members of 11 kindred with the nail-patella syndrome were studied. Twelve patients who had electron microscopic examinations of renal tissue had abnormalities of the glomerular basement membrane. An unaffected family member did not. This lesion consisted of irregular basement membrane thickening, epithelial foot process fusion and the presence of fibrillar collagen-like material within the substance of the membrane. Many patients also showed areas of increased lucency giving the membrane a "moth-eaten" appearance. The presence of the ultrastructural lesion bore no relation to the presence or absence of abnormalities by light or immunofluorescent microscopy and also no relation to demonstrable alterations of renal function. The determinants of clinically significant nephropathy are unknown but in most patients the prognosis is favorable.