The July 2003 human reference sequence (NCBI Build 34) was produced by the International Human Genome Sequencing Consortium.

Sample position queries

A genome position can be specified by the accession number of a sequenced genomic clone, an mRNA or EST or STS marker, or a cytological band, a chromosomal coordinate range, or keywords from the GenBank description of an mRNA. The following list shows examples of valid position queries for the human genome. See the User's Guide for more information.

   Genome Browser Response:

chr7 Displays all of chromosome 7
20p13 Displays region for band p13 on chr 20
chr3:1-1000000 Displays first million bases of chr 3, counting from p arm telomere
scf1:1-1000000 Displays first million bases of scaffold 1 of an unmapped genome assembly
chr3:1000000+2000 Displays a region of chr3 that spans 2000 bases, starting with position 1000000

D16S3046 Displays region around STS marker D16S3046 from the Genethon/Marshfield maps. Includes 100,000 bases on each side as well.
RH18061;RH80175 Displays region between STS markers RH18061;RH80175. Includes 100,000 bases on each side as well. This syntax may also be used for other range queries, such as between cytobands and uniquely-determined ESTs, mRNAs, refSeqs, etc.

AA205474 Displays region of EST with GenBank accession AA205474 in BRCA1 cancer gene on chr 17
AC008101 Displays region of clone with GenBank accession AC008101
AF083811 Displays region of mRNA with GenBank accession number AF083811
PRNP Displays region of genome with HUGO Gene Nomenclature Committee identifier PRNP
Displays the region of genome with RefSeq identifier NM_017414
Displays the region of genome with protein accession number NP_059110
Displays the region of genome with LocusLink identifier 11274

pseudogene mRNA Lists transcribed pseudogenes, but not cDNAs
homeobox caudal Lists mRNAs for caudal homeobox genes
zinc finger Lists many zinc finger mRNAs
kruppel zinc finger Lists only kruppel-like zinc fingers
huntington Lists candidate genes associated with Huntington's disease
zahler Lists mRNAs deposited by scientist named Zahler
Evans,J.E. Lists mRNAs deposited by co-author J.E. Evans

Use this last format for author queries. Although GenBank requires the search format Evans JE, internally it uses the format Evans,J.E..

Assembly details

This sequence covers about 99 percent of the gene-containing regions in the genome, and has been sequenced to an accuracy of 99.99 percent. Of note in this release is the addition of the pseudoautosomal regions of the Y chromosome. This sequence was taken from the corresponding regions in the X chromosome and is an exact duplication of that sequence.

There are 2,843,433,602 finished sequenced bases in the ordered and oriented portion of the assembly, which is an increase of 0.4 percent, or approximately 11 Mb, over the Build 33 assembly. The reference sequence is considered to be "finished", a technical term indicating that the sequence is highly accurate (with fewer than one error per 10,000 bases) and highly contiguous (with the only remaining gaps corresponding to regions whose sequence cannot be reliably resolved with current technology). Future work on the reference sequence will focus on improving accuracy and reducing gaps in the sequence.

Some sequence joins between adjacent clones in this assembly could not be computationally validated because the clones originated from different haplotypes and contained polymorphisms in the overlapping sequence, or the overlap was too small to be to be reliable. In these instances, the sequencing center responsible for the particular chromosome has provided data to support the join in the form of an electronic certificate. These certificates may be reviewed through the link below.

For further information on NCBI Build 34, see the NCBI Build 34 release notes.

Bulk downloads of the sequence and annotation data are available from the UCSC downloads server via ftp or http. The hg16 annotation tracks were generated by UCSC and collaborators worldwide. See the Credits page for a detailed list of the organizations and individuals who contributed to the success of this release.

Statistical information