Papillon-Lefevre syndrome (PLS) is an autosomal recessive form of palmoplantar ectodermal dysplasia, characterized by palmoplantar hyperkeratosis and severe early-onset periodontitis. The presence of severe periodontitis distinguishes PLS from other palmoplantar keratodermas. As part of our efforts to study the genetic basis of periodontitis susceptibility, we performed a genome-wide search to identify major loci for PLS in 44 individuals (14 affected) from 10 consanguineous PLS families. We have identified evidence for linkage of a PLS gene on 11q14-q21. A maximum two-point logarithm of the odds (LOD) score of 8.24 was obtained for D11S1367 at a recombination fraction of theta = 0.00. Multipoint analysis resulted in a LOD score of 10.45 and placed the gene for PLS within a 4-5 cM genetic interval. This genetic interval, flanked by D11S4197 and D11S931, contains more than 50 cDNAs and 200 expressed sequence tags (ESTs). This refinement of the candidate region for a PLS gene is in agreement with other recent reports of linkage for PLS to chromosome 11q14-q21 and should help in identification of the gene for PLS. Am. J. Med. Genet.79: 134-139, 1998. (C) 1998 Wiley-Liss, Inc.