mutation of the androgen receptor gene - proteus

[ArchivalUser]

A genotypic male is born with a complete loss of function mutation of the androgen receptor gene. How will this individual develop?

A. Normal testes; normal labia, clitoris, and lower vagina; absent uterus and fallopian tubes
B. Normal testes; normal labia, clitoris, and lower third of the vagina; normal uterus and fallopian tubes
C. Normal testes; normal penis, normal uterus and fallopian tubes
D. Normal testes; normal penis; normal prostate, vas deferens, and seminal vesicles
E. Absent testes; normal labia, clitoris, and lower vagina; absent uterus and fallopian tubes
F. Absent testes; normal labia, clitoris, and lower vagina; normal uterus and fallopian tubes

[ArchivalUser]

Choice (A) is the correct answer. Complete androgen resistance, also known as testicular feminization syndrome, results from abnormal androgen receptors. Individuals are genetically male but do not respond to the effects of testosterone. The testicles are present and are typically embedded in labia majora or the inguinal canal. Since cells do not respond to testosterone, the Wolffian duct degenerates, and a normal internal male reproductive tract does not form. In addition, the testes secrete anti-müllerian hormone, which results in regression of the müllerian duct. This results in an absent uterus, cervix, fallopian tubes, and upper third of the vagina. The external genitalia by default develop into normal female external genitalia, since cells are unresponsive to the effects of testosterone. The net result is a normal labia, clitoris, and lower vagina with an absent uterus, cervix, fallopian tubes, and upper third of the vagina. The testicles are surgically removed in patients with testicular feminization syndrome, because the testes are at an increased risk of developing malignancies. The other choices are incorrect.