[HapMap announcements] incorrect genomic position for merged SNPs in release #23 data files

[Marcela K. Tello-Ruiz]

This message is to inform you that the position of ~24,500 SNPs was 
inadvertently entered incorrectly in HapMap release #23 bulk files 
(genotypes and frequencies).

The affected SNPs fall in the category of merged SNPs, which for this 
release, consist of SNPs whose rs identifier in a previous dbSNP build 
(NCBI build 35) were merged under new rs identifiers in dbSNP build 126 
(NCBI build 36).

A complete list of affected SNPs can be found here:

http://www.hapmap.org/genotypes/2008-01/positional_errors/

The format of the above list(s) consist of merged rsid, incorrect 
(ncbi_b35) and corrected (ncbi_b36) position (strand is also given in 
parenthesis, if affected by this glitch).

rs#	ncbi_b35	ncbi_b36

We emphasize that GENOTYPES ARE NOT AFFECTED by this glitch.
Only chromosomal position (ncbi_b35 coordinates given instead of 
ncbi_b36 coordinates) were affected. In consequence, determination of 
reference allele for allele/genotype frequency calculations may have 
also been affected, as well as strand orientation in a handful of cases 
(18-23 SNPs).

All errors are being corrected in NEW genotypes and frequency files, 
which will be made available shortly as a new HapMap release #23a.

Our sincere apologies for any inconvenience this may have caused you.


-- 
Marcela Karey Tello-Ruiz, PhD
HapMap Data Coordination Center