is part of part of chromosomal region New term request for SO. An extended part of a chromosome representing a term of convenience in order to hierarchically organize morphologically defined chromosome features: chromosome > arm > region > band > sub-band. http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation and http://people.rit.edu/rhrsbi/GeneticsPages/Handouts/ChromosomeNomenclature.pdf, both of which define the nomenclature for the banding hierarchy we use here: chromosome > arm > region > band > sub-band Note that an alternate nomenclature for this hierarchy is here (http://www.ncbi.nlm.nih.gov/Class/MLACourse/Original8Hour/Genetics/chrombanding.html): chromosome > arm > band > sub-band > sub-sub-band The descriptor 1p22.3 = chromosome 1, short arm, region 2, band 2, sub-band 3. This is read as "one q two-two point three", not "one q twenty-two point three". chromosome arm chromosome part