About one in to 1, boys are born with Klinefelter's syndrome the presence of an extra X chromosome, the female sex chromosome , which can cause gynecomastia. About Cancer generously supported by Dangoor Education since Featured Issue Featured Supplements. However, one meta-analysis notes that many of these claims are supported by poor quality evidence. While gynecomastia can be embarrassing, it rarely has a serious cause.
Enlarged breasts in men (gynecomastia) - Symptoms and causes - Mayo Clinic