Edwards syndrome karyotype, illustration - stock illustration

Karyotype showing the arrangement of chromosomes in a male or female with Edwards syndrome (trisomy-18). Edwards syndrome is caused by a chromosomal anomaly: the 18th set having three rather than the normal two chromosomes. In karyotyping, chromosomes are arranged in numbered pairs according to a standard classification. The male set differs from the female in the sex pair (bottom right); a female would have XX rather than XY. A male Edwards karyotype is written: 47, XY, +18, a female - 47, XX, +18. The normal chromosome count is 46, 23 from maternal and 23 from paternal origin. Labelled computer illustration