Human Genome Project: Chromosome 22

The Wellcome Trust Sanger Institute played a substantial role in the sequencing and interpretation of the human genome, contributing almost one third of the gold-standard sequence, published in 2004. The Institute engaged in collaborative projects to sequence 9 of the 23 human chromosomes. This document is historical, presented here to provide a complete record. It might not have been updated and is a contemporary account.

Chromosome 22 publication front cover.

Chromosome 22 publication front cover. [Reprinted by permission from Macmillan Publishers Ltd: [Nature] (402 (6761): 445 - 562), ©1999]


The sequence of human chromosome 22 was completed in December 1999. An international consortium of sequencing centres released into the public domain the genetic code of the 33.5 million bps that comprise the euchromatic portion of human chromosome 22. This was the first time a human chromosome has been sequenced and included the largest continuous sequence determined from any organism at the time (23 million bps).

Chromosome 22 is the second smallest of the human autosomes. The short arm (22p) contains a series of tandem repeat structures including the array of genes that encode the structural RNAs of the ribosomes, and is highly similar to the short arms of chromosomes 13, 14, 15 and 21. The long arm (22q) is the portion of human chromosome 22 that contains the protein coding genes and this is the region that has now been sequenced. The completed sequence consisted of 12 contiguous segments covering 33.4 million bps separated by 11 gaps of known size. One of these gaps has subsequenctly been closed by the Oklahoma group. The sequence is estimated to cover 97% of 22q, and is complete to the limits of currently available reagents and methodologies. The largest contiguous contig is >23 million bps, and at that time, this was the largest piece of continuous sequence determined.

  • Sequencing Centres: Wellcome Trust Sanger Institute, Keio University School of Medicine, The University of Oklahoma, Washington University School of Medicine
  • Collaborators: The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, University of Alberta, Albert Einstein College of Medicine, California Institute of Technology, Karolinska Hospital


  • The DNA sequence of human chromosome 22.

    Dunham I, Shimizu N, Roe BA, Chissoe S, Hunt AR, Collins JE, Bruskiewich R, Beare DM, Clamp M, Smink LJ, Ainscough R, Almeida JP, Babbage A, Bagguley C, Bailey J, Barlow K, Bates KN, Beasley O, Bird CP, Blakey S, Bridgeman AM, Buck D, Burgess J, Burrill WD, O'Brien KP et al.

    Nature 1999;402;6761;489-95

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