Mapping the X Chromosome

Abstract

DR. UTA FRANCKE: Before moving on to the mapping of the X chromosome, I would like to review briefly with you the background of and progress in human gene mapping. Figure 35 shows the information on human genetic traits that has been accumulated and compiled by Dr. Victor McKusick in his catalogs. The curve depicting the chromosomal assignments of autosomal traits shows a steep rise in the early 1970s due to the advent of somatic cell genetic techniques, and then flattens a little bit because most genes that can easily be mapped in somatic cell hybrids had been mapped. More recently, the slope increased again due to new technology providing new genetic markers such as DNA segments and antigens defined by monoclonal antibodies. There are now almost 300 loci mapped to specific autosomes, and slightly more than 100 on the X. This information has been reviewed and updated periodically at six international workshops on human gene mapping (79–84).