snps 12052146 Analysis of single nucleotide polymorphisms in human chromosomes 21 and 22 S Balasubramanian, P Harrison, H Hegyi, P Bertone, N Luscombe, N Echols, P McGarvey, Z Zhang, M Gerstein http://papers.gersteinlab.org/e-print/snps/all.pdf http://genecensus.org/pseudogene keck pseudogenes,student