The nevoid basal cell carcinoma syndrome (NBCC) is an autosomal dominant multisystem disorder characterized by multiple basal cell carcinomas, jaw cysts, pits of the palms and/or soles, ectopic calcification, and skeletal malformations. The NBCC gene has recently been mapped to chromosome 9q22.3-9q31. In order to further define the region containing the NBCC gene, we have analyzed 137 individuals from eight families for linkage, using 11 markers from the region. Eight markers showed statistically significant evidence for linkage to NBCC. Three markers (D9S180, ALDOB, and D9S173) showed no definite recombination with the disease locus. All families showed some evidence for linkage to markers in this region. On the basis of the inspection of individual recombinants and previously published information about map location, we suggest the following order for the markers: D9S119-D9S12-D9S197-D9S196-(NBCC,D9S180 -D9S173,ALDOB)-D9S109- D9S127-(D9S53,D9S29). We are currently developing YAC contigs for the most closely linked markers, to further refine the location of the NBCC gene.