Addition of GRCh38 patch 14 sequences to hg38

[Gerardo Perez]

Hello Everyone,

We are pleased to announce the addition of GRCh38 patch release 14 to the hg38 assembly. hg38 has been updated with patches since its release in 2013. The GRC patch releases do not change any previously existing sequences; they simply add new sequences for fix patches or alternate haplotypes that correspond to specific regions of the main chromosome sequences. For most users, the patches are unlikely to make a difference and may complicate the analysis as they introduce more duplication.

More information on how patch sequences are incorporated can be found on the Patching up the Genome blog post. The blog post contains details about the new /latest, /initial, and /p14 download directories on the downloads server. With the addition of new sequences to hg38, we can expect to see BLAT return more matches to the genome.

• The initial/ subdirectory contains files for the initial release of GRCh38, which has 455 sequences, 261 alternate sequences, and no fix sequences. It is the same as the parent download directory. This is probably the best genome file for aligners and most analysis tasks, a version called "analysisSet" for the human genome.
• The p14/ subdirectory contains files for GRCh38.p14 (patch release 14), which has 711 sequences, 351 alternate sequences, and 166 fix sequences.
• The latest/ symbolic link points to the subdirectory for the most recent patch version.

We would like to thank the Genome Reference Consortium for creating the patches for hg38.