34.
Testicular Feminisation Syndrome.
| a. | is associated with 46XX | False |
| b. | the gonads produce testosterone | True |
| c. | presentation is usually with secondary amenorrhoea | False |
| d. | axillary and pubic hair are absent | True |
| e. | breast development is normal | True |
| f. | dysgerminoma may develop in the gonads, which should be removed after development of secondary sexual characteristics | True |
Testicular feminisation syndrome is 46XY.
Most now prefer the term “Androgen Insensitivity Syndrome”, which is more accurate and sensitive.
The gonads are testes and produce testosterone.
The unique thing is that the tissues are resistant to testosterone.
Either because they lack the binding receptor.
Or because there is
deficiency of the enzyme which converts testosterone to the active hormone dihydrotestosterone.
Development is apparently female, with absence of the uterus and ovaries, but normal vulva and a short vagina.
The reason is that all embryos develop female external genitalia unless exposed to the effects of testosterone.
Breast development occurs due to peripheral conversion of androgens to oestrogens.
Axillary and pubic hair do not develop, reflecting the resistance to testosterone.
With no
uterus and testes for gonads, there is no question of menstruation, so the
presentation is with primary amenorrhoea.
The gonads are removed after development of secondary sexual characteristics, because of the risk of malignancy developing.
After which oestrogen therapy is instituted.
The inheritance is X-linked recessive. (See MCQ8, question 2.)