FINE MAPPING OF THE NAIL-PATELLA SYNDROME LOCUS AT 9Q34

Nail-patella syndrome (NPS), or onychoosteodysplasia, is an autosomal dominant, pleiotropic disorder characterized by nail dysplasia, absent or hypoplastic patellae, iliac horns, and nephropathy. Previous studi es have demonstrated linkage of the nail-patella locus to the ABO and adenylate kinase loci on human chromosome 9q34. As a first step toward isolating the NPS gene, we present linkage analysis with 13 polymorph ic markers in five families with a total of 69 affected persons. Two-p oint linkage analysis with the program MLINK showed tight linkage of N PS and the anonymous markers D9S112 (LOD = 27.0; theta = .00) and D9S3 15 (LOD = 22.0; theta = .00). Informative recombination events place t he NPS locus within a 1-2-cM interval between D9S60 and the adenylate kinase gene (AK1).