A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.
http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=FR&Expert=96189 2011 France scientific and technical information chromosomes, human, pair 4 uniparental disomy
--- http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=FR&Expert=96180 2011 France scientific and technical information purpura, thrombotic thrombocytopenic uniparental disomy chromosomes, human, pair 4