The American Association for Klinefelter Syndrome Information and Support (AAKSIS) is a national volunteer association with the mission of education, support, research, and understanding of 47 XXY and its variants, collectively known as Klinefelter syndrome.

The Hormone Foundation is a nonprofit organization started by the Endocrine Society. The organization promotes the prevention, treatment, and cure of hormone-related conditions through public outreach and education.

KS&A is focused on Knowledge, Support, and Action. It's a nonprofit education and support organization for people who have Klinefelter syndrome or other conditions caused by extra X and/or Y chromosomes.

The March of Dimes tries to improve the health of babies by preventing birth defects, premature birth, and early death. March of Dimes supports research, community services, education, and advocacy to save babies' lives. The organization's website has information on premature birth, birth defects, birth defects testing, pregnancy, and prenatal care.

The National Institute of Child Health and Human Development (NICHD) is part of the U.S. National Institutes of Health. The NICHD conducts and supports research related to the health of children, adults, and families. NICHD has information on its Web site about many health topics. And you can send specific requests to information specialists.