Q:
Found your paper (http://genomebiology.com/2012/13/9/r51) about
pseudogene’s very informative.

Have been looking at the distribution of pseudogenes(
http://nagarjunv.blogspot.se/2013/12/pseudogene-distribution-across-human.html)
using the Ensemble annotation as well as that found on pseudogene.org.

However, pseudogenes seem to be lacking on short arm of chr13, 14, 15 and 22.

Could you please let me know if this is a known biological pattern or
some missing annotation?

A:
In human, chromosomes 13, 14, 15, 21 and 22 are acrocentric. They are made of a very long arm and a very short arm that is homologous across the five chromosomes. Only the long arm has been sequenced and annotated. This is way there are no pseudogenes (or genes for that matter of fact) annotated on those chromosome arms.

For more info please see:
http://www.nature.com/nature/journal/v428/n6982/full/nature02379.html
and
http://www.sanger.ac.uk/about/history/hgp/chr13.html