In the past 10 years, numerous human genomic variants have been
discovered and catalogued, mostly through the efforts of the
International HapMap project and personal genome studies .
Information on human genomic variants may serve as a valuable
resource for developing personalized medicine because some of
these variants could potentially predispose humans to complex
diseases. The 2009 version (version 130) of the dbSNP database
included approximately 13.9 million (13.9 M) single nucleotide
polymorphisms (SNPs) and 4.5 M small insertions and deletions
(indels). However, many issues need to be addressed before
personalized medicine becomes a reality. These include an
understanding of: the kind and number of variants that exist in
the entire human genome; the number of populations and
individuals needed to detect most, if not all, human genomic
variants with efficiency and accuracy; the frequency of common
and rare variants in an individual genome; and finally the
number of variants that influence human disease