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The genetic sequence map of human chromosome 1, the last and largest of the 23 chromosomes to be mapped, has been completed and an analysis published in the journal Nature [Gregory SG et al. (2006) Nature 441, 315-321]. A team of over 160 collaborators in the UK and the US has taken nearly ten years to produce the finished sequence. Lead investigator Simon G. Gregory, who led the project whilst at the Wellcome Trust Sanger Centre in the UK, commented: "This achievement effectively closes the book on an important volume of the Human Genome Project" (see press release). This is because, following the release of the draft and ‘complete’ human genome sequences in 2001 and 2003 respectively, chromosome 1 is the last of the chromosomes to be fully annotated, with the positions of genes and other important structural features mapped on to the basic genetic sequence. Now, the focus of the Human Genome Project (HGP) is likely to move increasingly from direct analysis of the genome sequence, towards attempts understand the genetic contribution to health and disease.

Chromosome 1, which represents around 8% of the human genome, is dense in genes (3,141 and 991 pseudogenes); these include around one thousand novel genes (see project website). It is thought that many of these are important in human health, and further study of the chromosome may lead to the discovery of novel diagnostics and therapeutics. Several genes involved in disease have already been identified using the annotated chromosome sequence. Dr Brian Schutte of the University of Iowa in the US, who in collaboration with the UK Sanger team located a chromosome 1 gene involved in both a rare human orofacial disease and the common form of cleft lip and palate commented: “Our experience demonstrates two important issues. Firstly, gene discoveries in rare diseases can contribute directly to the understanding of common diseases. Secondly, sequencing efforts accelerate gene discovery of not only rare genetic disorders, but also common diseases that place the greatest burden on our healthcare system".