What condition is associated with an increased risk for breast cancer in males?

Klinefelter syndrome is associated with an increased risk of breast cancer in males due to the presence of an extra X chromosome, which occurs in the condition. Males typically have one X and one Y chromosome (46,XY), while those with Klinefelter syndrome have at least one additional X chromosome (e.g., 47,XXY). This abnormal chromosomal pattern leads to an imbalance of sex hormones, resulting in a higher estrogen-to-androgen ratio. Increased estrogen levels can promote breast tissue development and the risk of developing breast carcinoma.

Additionally, individuals with Klinefelter syndrome may also have gynecomastia (the enlargement of breast tissue), which further highlights the hormonal influence and increased breast cancer risk. The other conditions listed do not have a similar direct association with breast cancer in males. For example, Turner syndrome primarily affects females, while Marfan syndrome and Down syndrome do not have significant links to male breast cancer incidence.