Genetics and chromosome punctuation
Karyotype is the chromosome complement of an individual, tissue, or cell line. Karyotype is expressed as the number of chromosomes in a cell including the sex chromosomes, a description of the sex chromosome composition, and (whenever applicable) any chromosome abnormality.
In karyotype expressions, the sex chromosomes are separated from the number of chromosomes by a comma. There is no space after the comma.
The normal human karyotypes are 46,XX (female) and 46,XY (male).
Descriptions of chromosome abnormalities are presented after the sex chromosomes and are listed in numeral order, separated by a comma.
Down syndrome 47,xx,+21 (female) or 47,XY,+21 (male).
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