The Human Genome Project is providing a wealth of information
about the human gene repertoire, and promises to furnish a
complete genome sequence (and thereby a complete gene catalog) by
the year 2005. This enormous output of data is beginning to be
complemented by large scale studies designed to uncover normally
occurring variations within human gene sequences. Much of this
variability is very subtle, often comprises single nucleotide
polymorphisms (SNPs) which are ideally compatible with a number
of large scale detection procedures. SNPs will be the basis of
future highly dense polymorphic marker maps, and those related to
known genes can be exploited in genetic association studies aimed
at defining the genetic basis of all manner of complex
phenotypes, not least disorders such as mental illness, diabetes,
cardiovascular disease and cancer. All indications are that
100,000-200,000 human genome SNPs will be identified within the
next two years.
