We report a highly polymorphic, sequence-tagged microsatellite site (S
TMS) at the D5S99 locus that was previously identified by a less infor
mative restriction fragment length polymorphism (RFLP). This marker, w
hich was also localized to the physical map of chromosome 5q by fluore
scent in situ hybridization (FISH), should assist in the precision map
ping of genes in the area 5q33-34.