A LINKAGE MAP OF HUMAN-CHROMOSOME-15 WITH AN AVERAGE RESOLUTION OF 2 CM AND CONTAINING 55 POLYMORPHIC MICROSATELLITES

We have constructed a 2.0 centiMorgan (cM) resolution genetic linkage map for chromosome 15q that contains 55 polymorphic satellites and 3 R FLPs that have placed on the map with odds for order of at least 1,000 :1. Genotypes from 67 polymorphic loci (64 polymorphic microsatellites ) were used to construct the map. Nine genes are included in the 1,000 :1 map and 37 markers have heterozygosities of at least 70%. The sex-e qual map length is 128 cM and the largest genetic interval is 11 cM (1 5.5 cM on the female map). The female and male map lengths are 150 cM and 106 cM, respectively. The map was constructed with 'MultiMap' and is based on the CEPH reference pedigrees and includes over 12,000 new genotypes. A sub-set of 12 markers spanning the length of the linkage map were genotyped in a somatic cell hybrid panel with breakpoints tha t divided 15q into five segments. Cytogenetic placement agreed with th e linkage positions for each of the microsatellites tested with the ex ception of one (ACTC) which failed to give consistent results. Ten spo ntaneous new mutations were identified from a subset of 42 polymorphic microsatellites (out of a total of 20,420 transmissions), giving an a pparent observed spontaneous mutation rate of 5x10(-4) per locus. An i ntegrated map of chromosome 15q was also constructed with the microsat ellite markers described here and previously genotyped RFLP-based mark ers. The sex average map spans 144.7 cM with an average distance betwe en unique map locations of 3.5 cM and a maximum intermarker distance o f 11.5 cM. These genetic linkage maps can be considered baseline maps for 15q which will be useful for physical mapping and the localization of disease genes and other genes of interest.