Engelsk definition
Homologous chromosomal regions at either end of the X CHROMOSOME or Y CHROMOSOME. These two regions pair regularly at male MEIOSIS and undergo RECOMBINATION. Pseudoautosomal region 1 (PAR1) is located at the tip of the short 'p' arms (Xp22 and Yp11) and Pseudoautosomal region 2 (PAR2) is located at the tip of the long 'q' arms (Xq28 and Yq12).