Karyotype showing the arrangement of chromosomes in a female with Cri du Chat syndrome, a classical chromosome disorder which involves a deletion of chromosome 5. In karyotyping, chromosomes are arranged in numbered pairs according to a standard classification. A normal female karyotype differs from a male only in the sex chromosomes; a male would have XY rather than XX. Cri du Chat in a female is written: 46,XX, del(5)(p13). The normal chromosome count is 46, 23 from maternal and 23 from paternal origins. Approximate magnification: x350 at 35mm size.