August 9, 2000
Researchers from the Johns Hopkins Children's Center have determined that over the course of their lives, women who possess the same sex chromosomes as men -- by virtue of a genetic mutation that leaves them completely insensitive to male sex hormones called androgens -- can still lead active, normal sex lives. The study, which appears in the August 2000 issue of The Journal of Clinical Endocrinology & Metabolism, suggests that androgens, long thought to enable women to experience orgasm and heighten their sex drive, may not be essential after all.
"Our current ideas about hormone-to-behavior interactions may not generalize to humans," says Amy Wisniewski, Ph.D., lead author of the study. "The women reported that they had a good libido and normal sexual activity -- without sensitivity to androgens."
The research team, led by pediatric endocrinologist Claude Migeon, M.D., studied 14 women with Complete Androgen Insensitivity Syndrome (CAIS). Unlike previous studies of CAIS, Migeon and his research team followed the women's medical history well into their adult years. By the end of the study, most subjects were between the ages of 30 and 60 years of age.
CAIS results from a gene mutation on the X-chromosome that makes women unresponsive to androgens. Among androgens' many roles are guiding normal male development and, later in life, influencing male and female sex drives. If sensitive to androgens, normal fetuses with the XY sex chromosomes develop into boys and those with XX sex chromosomes develop into girls. Without sensitivity to androgens, XY fetuses develop into girls. A woman with CAIS is physically female, but with an underdeveloped uterus and fallopian tubes. In addition, she has latent testes unconnected and embedded in her lower body cavity. Since there are no outward signs of CAIS, women don't usually learn of their condition until puberty, when they fail to menstruate and visit a physician or specialist to find out why. The news is often a complete surprise, Wisniewski says.
Women in the long-term study knew they had a condition called CAIS, though many did not fully understand what the term meant. They were assessed for physical and gender development from childhood to adulthood, their knowledge about CAIS and their responsiveness to treatment options. Overall, they reported satisfaction with their gender development, sexual function, body image and femininity. Eight of the 14 women exhibited no understanding of CAIS and most desired more information about their condition. Women in the study requested that their identities remain confidential.
"These women were well-adjusted, psychologically and sexually," says Wisniewski. "But a lot of the women had some psychological counseling, and we believe it helped them."
The two most common problems associated with CAIS that require treatment are the psychological impact of perceived or real social stigma and an unusually high incidence of bone diseases such as osteoporosis. Although a majority of the women said they were satisfied with the counseling and surgical treatment they received, estrogen therapy designed to thwart bone disease -- prescribed soon after their CAIS diagnosis -- was often resisted by the women, Migeon says.
"The women can't understand why they need to take it, so there is a lack of compliance with estrogen," Migeon says. "But these women live well into adulthood, so treatment is very important."
Researchers from Columbia University, the University of Miami in Florida, and The Johns Hopkins School of Public Health also contributed to the study, which was funded by a grant from The Genentech Foundation for Growth and Development. Additional funding was made available by the National Institutes of Health. To learn more about sexual development syndromes online, visit: http://www.med.jhu.edu/pedendo/intersex/index.html