Minimaps For Human Cells

FINDING A SINGLE GENE AMONG THE ESTIMATED 100,000 genes scattered along the 23 pairs of chromosomes in human cells is every bit as daunting as finding the proverbial needle in a haystack. But now the quest has been made simpler, at least for two of those chromosomes. As reported in the research journal Nature, investigators in Paris have published the first map to describe in the correct order all the most important subsections of the 21st chromosome -- the one that harbors genes associated with Down syndrome, Alzheimer's disease and other neurological disorders. Simultaneously, researchers in Boston published a similar map, in Science, for the Y chromosome, which is vital to male development.

These achievements will help researchers decipher the genetic blueprint of human beings. They will not, however, by themselves lead to useful therapies anytime in the near future. Because of the complicated interplay between heredity and environment, knowing where a gene is located and what it looks like is only a first step. Years of research are still required to determine how and why a particular gene causes a disease and what treatments will be needed to cure it.