General Medical Information

45,X/46,XY Unambiguous Female External Genitalia

Joe Leigh Simpson

45,X/46,XY individuals may have Turner’s stigmata and thus be clinically indistinguishable from 45,X individuals. Such individuals usually are normal in stature and show no somatic anomalies. As in other types of gonadal dysgenesis, the external genitalia, vagina, and müllerian derivatives remain unstimulated because of the lack of sex steroids. Breasts fail to develop, and little pubic or axillary hair develops. If breast development occurs in a 45,X/46,XY individual, an estrogen-secreting tumor such as gonadoblastoma or dysgerminoma should be suspected (148). Virilization also has been claimed to result from gonadotropin stimulation of streak gonads.

Although streak gonads of 45,X/46,XY individuals may be histologically indistinguishable from those of 45,X individuals, gonadoblastomas or dysgerminomas develop in about 15% to 20% of 45,X/46,XY individuals. Neoplasia may develop in the first or second decade of life. Despite the possibility that a locus on Yq may protect against neoplasia, gonadal extirpation is recommended for all 45,X/46,XY individuals having female external genitalia. The uterus should be retained because pregnancy may be achieved through donor oocytes or donor embryos. Gonadectomy usually can be accomplished by laparoscopy. It is preferable to remove only gonads, but technically it may be necessary to remove the adnexa as well. Laparotomy should only rarely prove necessary.