Hap Map Project - Bgbunict.it

Genotyping in phase II was attempted for about 4.4 million
distinct SNPs, of which roughly 1.3 million either could
not be
typed,
were not
polymorphic
in any
of the
populations, or did not pass genotyping quality control
filters.
Certain regions of the genome were recognized as being
challenging to study, such as centromeres, telomeres,
gaps in genome sequence, and segmental duplications,
regions declared to be not HapMapable.