Ornithine aminotransferase-related sequences map to two nonadjacent intervals on the human X chromosome short arm.

Using a panel of human/rodent somatic cell hybrids segregating human X/autosome translocations and deletions, we have refined the localization of the X-linked sequences homologous to ornithine-delta-aminotransferase (OAT), the structural locus for which (OAT) maps to chromosome 10. OAT-related ("-like") (OATL) sequences mapped to two nonadjacent intervals: OATL1 mapped to Xp11.3-p11.23, while OATL2 mapped to Xp11.22-p11.21. X-linked OATL1 sequences polymorphic for ScaI and StuI map to the more distal interval in Xp11.3-p11.23. These results should help guide long-range cloning and mapping studies, as well as refine the genetic linkage map in this region of the X chromosome.