| Sex chromosomes | Phenotype | Characteristics |
|---|---|---|
| XX | Female | Female traits |
| XY | Male | Male traits |
| XXY, XXYY, XXXY | Klinefelter syndrome | Male traits, tall, small testes, reduced facial and pubic hair |
| XO | Turner syndrome | Female traits, short, low hairline, broad chest, neck folds |
| XXX, XXXX, XXXXX | Poly-X females | Female traits, tall and thin |
| XYY | XYY males | Male traits, tall |