what is the difference between GRCh37 and hg19 ?
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8.0 years ago
jack ▴ 950

Hi all,

What is the difference between GRCh and hg? I have small RNA interaction data with genome like below and they have used hg19 for mapping the reads. I want to use GTF file in Ensemble which is based on GRCh. but I was wondering the hg and GRCh are the same? If not, where can I find the GTF file for the hg19?

chromosome  start    end      interaction ID  alignment score of target part  strand
chr2        1.9E+08  1.9E+08  human08246      32                              +
chr16       5.2E+07  5.2E+07  human04514      32                              -
chr3        1.1E+08  1.1E+08  human11115      36                              +
chrM        14360    14382    human08122      34                              +

RNA-Seq Assembly genome alignment • 37k views
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But still, I couldn't figure it out whether hg and GRCh is the same or not. Could you please elaborate more?

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Can I make a similar answer in here? Might be useful to others too. If its innapropiate take the according action to fix it, sorry.

Which is the difference between Homo_sapiens.GRCh38.91 and Homo_sapiens.GRCh38.78? Can I use a Homo_sapiens.GRCh38.91.bed as annotation to a genome referenced to Homo_sapiens.GRCh38.78?

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The term "GRCh38" refers to the genomic assembly. The ".78" and ".91" refer to the version of gene annotation provided by Ensembl, i.e. where do introns/exons/etc start and end. To my knowledge, the genomic sequence for "GRCh38.78" and "GRCh38.91" should be identical and only the gene annotation should differ.

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In GRCh37.91, what does that .91 mean?

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Hi Pierre..thanks for the link...I am sorry that I am still confused because when I google GRCh37.91, it does not show up...that ''.91'' comes along only with GRCh38. I understand that GRCh37 is the older version than GRCh38. But is that '0.91' a 'Patch'? If so, can it be used for both GRCh 37 or GRCh38?

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Hi Pierre..thanks for the link...I am sorry that I am still confused because when I google GRCh37.91, it does not show up...that ''.91'' comes along only with GRCh38. I understand that GRCh37 is the older version than GRCh38. But is that '0.91' a 'Patch'? If so, can it be used for both GRCh 37 or GRCh38?

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8.0 years ago
Dan D 7.3k

I believe the genomic content for the two is identical, except for the mitochondrial contig.

The contig names are also different. GRCh37 names them chr1, chr2,,chr3, etc, while hg19 just has 1, 2, 3.

Thus you can use the same GTF file for both (excluding mitochondrial, of course) if you do a simple replace operation for the contig names.

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and some degenerate bases have been replaced by 'N' for chr3 and chrY. see: http://plindenbaum.blogspot.fr/2013/07/g1kv37-vs-hg19.html

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ok, thanks, so the genomic coordinates of the genes are the same in hg and GRCh ?

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Although this is basically true, GRCh37 has a number of patches, which won't be included in hg19.

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3.0 years ago

More information to add (courtesy MatthewP): GRCh37 / hg19 / b37 / humanG1Kv37 - Human Reference Discrepancies

In essence: GRCh37 is identical to hg19 on the main contigs (chr1-24), but differ on chrM.

Kevin