XXY List - A private discussion list for which you must be an XXY to subscribe.

Understanding Klinefelter Syndrome - Also known as "XXY males" these persons have an extra sex chromosome, XXY instead of the usual male arrangement, XY. Many men go through life without any symptoms or knowledge of this genetic difference. This site explains causes, symptoms, treatments and resources.

Klinefelter's Syndrome Club UK - Aims to provide information, support and facilitate social contact where sought, between adults who have Klinefelter's syndrome and to offer a similar facility to their partners.

Klinefelter Syndrome - Overview and medical information.

Klinefelter's Syndrome gynecomastia - Male chest recontouring for large male breasts (gynecomastia) found in Klinefelter's Syndrome with surgical reduction by excision and liposuction. Before and after photographs, links, movies, and patient question and answer boards.

Klinefelter Syndrome? - A parent's point of view, with articles.

Genetic Org Home - Information about Klinefelter Syndrome, when it was first discovered, the common characteristics, and treatment.

American Association for Klinefelter Syndrome Information and Support (AAKSIS) - Email list, conference, membership, newsletter, regional groups and resource links.

Turner Center - Literature on XYY, Klinefelter, XXX, and Turner's Syndrome.

XXY Information (Klinefelter Syndrome) - Medical information, news, and links.

Yahoo!: XXYList - XXY is a genetic anomaly which occurs 1 in 500 in the general population today. Men with this condition usually have Klinefelters Syndrome. Offers joining instructions for this support group.

My Klinefelter's Syndrome Page - David Brager's story, with information about Klinefelter's.

[drkoop.com] Klinefelter's syndrome - A chromosome abnormality that affects only men and causes hypogonadism.