Human assembly and gene annotation


This site provides a data set based on the December 2013 Homo sapiens high coverage assembly GRCh38 from the Genome Reference Consortium. This assembly is used by UCSC to create their hg38 database. The data set consists of gene models built from the genewise alignments of the human proteome as well as from alignments of human cDNAs using the cDNA2genome model of exonerate.

This release of the assembly has the following properties:

  • contig length total 3.4 Gb.
  • chromosome length total 3.1 Gb (excluding haplotypes).

It also includes 261 alt loci scaffolds, mainly in the LRC/KIR complex on chromosome 19 (35 alternate sequence representations) and the MHC region on chromosome 6 (7 alternate sequence representations).

Watch a video on YouTube about patches and haplotypes in the Human genome.


As the GRC maintains and improves the assembly, patches are being introduced. Currently, assembly patches are of two types:

  • Novel patch: new sequences that add alternative sequence at a loci and will remain as haplotypes in the next major assembly release by GRC
  • Fix patch: sequences that correct the reference sequence and will replace the given region of the reference assembly at the next major assembly release by GRC.

The genome assembly represented here corresponds to GenBank Assembly ID GCA_000001405.20

Other assemblies

Gene annotation

The Ensembl human gene annotations have been updated using Ensembl's automatic annotation pipeline. The updated annotation incorporates new protein and cDNA sequences which have become publicly available since the last GRCh38 genebuild (December 2013).

In the current release, we continue to display a joint gene set based on the merge between the automatic annotation from Ensembl and the manually curated annotation from Havana. See the statistics table, right, for the corresponding GENCODE version number. The Consensus Coding Sequence (CCDS) identifiers have also been mapped to the annotations. More information about the CCDS project.

Updated manual annotation from Havana is merged into the Ensembl annotation every release. Transcripts from the two annotation sources are merged if they share the same internal exon-intron boundaries (i.e. have identical splicing pattern) with slight differences in the terminal exons allowed. Importantly, all Havana transcripts are included in the final Ensembl/Havana merged (GENCODE) gene set.

Vega logo Additional manual annotation of this genome can be found in Vega

Neanderthal genome

A preliminary assembly of the Neanderthal (Homo sapiens neanderthalensis) genome is available via the Neanderthal Genome Browser, an Ensembl-powered project based at the Max Planck Institute.

More information

General information about this species can be found in Wikipedia.



AssemblyGRCh38.p5 (Genome Reference Consortium Human Build 38), INSDC Assembly GCA_000001405.20, Dec 2013
Database version83.38
Base Pairs3,547,121,844
Golden Path Length3,096,649,726
Genebuild byEnsembl
Genebuild methodFull genebuild
Genebuild startedJan 2014
Genebuild releasedJul 2014
Genebuild last updated/patchedOct 2015
Gencode versionGENCODE 24

Gene counts (Primary assembly)

Coding genes20,313 (incl 512 readthrough)
Non coding genes25,180
Small non coding genes7,703
Long non coding genes14,896 (incl 197 readthrough)
Misc non coding genes2,307
Pseudogenes14,453 (incl 4 readthrough)
Gene transcripts199,184

Gene counts (Alternative sequence)

Coding genes2,489 (incl 36 readthrough)
Non coding genes1,547
Small non coding genes565
Long non coding genes810 (incl 22 readthrough)
Misc non coding genes172


Genscan gene predictions50,766
Short Variants149,490,457
Structural variants4,149,389