- American Association for Klinefelter Syndrome Information and Support (AAKSIS) - Email list, conference, membership, newsletter, regional groups and resource links.
- Genetic Org Home - Information about Klinefelter Syndrome, when it was first discovered, the common characteristics, and treatment.
- Klinefelter Syndrome - The Ohio Support Network - Specific health and educational resources for Ohio KS individuals and their families. Links to local and national healthcare, ongoing research, conferences, and support meetings.
- 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 - Overview and medical information.
- Klinefelter Syndrome Support - Educational and support information about Klinefelter Syndrome/XXY and its variants.
- MedlinePlus Medical Encyclopedia: Klinefelter Syndrome - Defines this condition, the causes, symptoms, treatment, prognosis, and complications.
- My Klinefelter's Syndrome Page - David Brager's story, with information about Klinefelter's.
- 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.
