Interestingly, both of your new sources have the same author as the original link you provided, Ajit Varki. The PNAS article does provide an original citation for the claim and it is another paper on which Ajit Varki was an author (
Angata et al., 2004).
Bearing in mind that the original paper used a human genome build from 2003 it is likely that more recent builds have improved the coverage in the region. In fact if you go to the UCSC site then you can see this by comparing the 2003 build with the more recent 2009 one between the
SIGLEC10 and
SIGLEC8 loci ( On the 2003 build this is chr19:56,612,450-56,647,230 and for the 2009 build it is chr19:51,920,751-51,955,107). In the earlier build there is a gap in the homology track for chimp of around 2kb (2000 nucelotides) which seems to be the putative deletion from the 2004 paper.
So perhaps Ajit Varki and his co-authors just haven't reanalysed their data with the more recent builds, have missed the more recent work and are still referencing the older research. The current data however seems to indicate that there is no such deletion and that rather there has indeed been some sort of pseudogenisation.
TTFN,
WK
Edited by Wounded King, : No reason given.