Yes, men can have XX chromosomes. This is a rare condition known as XX male syndrome or 46,XX testicular difference of sex development. While typically, women have two X chromosomes (XX) and men have one X and one Y chromosome (XY), some men possess two X chromosomes.
This occurs when a small portion of the Y chromosome, containing the SRY gene, which is responsible for male development, gets translocated onto one of the X chromosomes during the father's sperm formation. This translocation results in the man having the XX chromosomes but still possessing the SRY gene, leading to male development despite having the chromosomes usually associated with females.
The frequency of XX male syndrome is estimated at approximately 1 in 25,000 males. Men with this condition often have normal male external genitalia but may experience delayed puberty, infertility, or gynecomastia (enlarged breasts). Their testes are usually small.
In summary, despite having the XX chromosome pair, these individuals are genetically male due to the presence of the SRY gene on one of their X chromosomes.
