The term "YY" in the context of human genetics refers to a chromosomal configuration, not a gender. A human with a YY chromosomal makeup is biologically impossible. Normal human females have two X chromosomes (XX), and normal human males have one X and one Y chromosome (XY). The Y chromosome carries the genes that primarily determine maleness. For a person to have a YY composition, they would require a Y chromosome from both their mother and father, which is not possible. A mother only provides X chromosomes.
The references provided confirm this: Byju's explicitly states that a YY child is impossible. https://byjus.com/question-answer/is-there-a-yy-gender/ Other sources discuss XYY syndrome, a condition where males have an extra Y chromosome (XYY), resulting in 47 chromosomes instead of the usual 46. This is distinct from a YY configuration. https://www.healthline.com/health/xyy-syndrome The references related to Peptide YY (PYY) are irrelevant to the chromosomal gender question. These discuss hormonal secretions and are unrelated to the question of a YY gender. https://pubmed.ncbi.nlm.nih.gov/16174724/
However, in other contexts like fish genetics, YY males are discussed (though even then it describes a specific manipulation within the species, not a naturally occurring gender). https://idfg.idaho.gov/press/fish-and-game-develops-new-way-control-fish-populations Therefore, it's crucial to specify the context when discussing "YY". Without a specified context, a YY configuration is impossible for humans.
In summary, there is no YY gender in humans. The concept only exists in a very specific, manipulated biological context, and should not be interpreted as a naturally occurring human gender.
