Lim
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A genotypic male (XY) is born with feminized external genitalia. The testes are retained within the abdominal cavity, and the internal reproductive tracts exhibit the normal male phenotype. Which of the following could account for this abnormal development?
A. Complete androgen resistance
B. 5α-reductase deficiency
C. 17α-hydroxylase deficiency
D. Sertoli-only syndrome
E. Testicular dysgenesis
Sertoli-only syndrome had both male and female internal organs? even though they have MIF(Mullerian Inhibiting Factor from sertoli cells)?
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| docarchana
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B. due to lack of DHT.
sertoli only syndrome - dont know.
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| Lim
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docarchana,yes,it is.
in sertoli-only syndrome,it has MIF. so mullerian internal organ(femle internal organ) can't develop. but the explanation is different from my opinion. can anybody explain,please?
The answer is 5α-reductase deficiency
Explanation:
In utero differentiation of the Wolffian ducts into the normal male phenotypic internal reproductive tract requires testosterone, but not dihydrotestosterone. On the other hand, differentiation of the indifferent external genital slit into the penis, prostate, and scrotum does require dihydrotestosterone. A congenital absence of 5α-reductase in these tissues will result in feminization. If left untreated, the affected individuals are generally phenotypic females until puberty, at which time increased amounts of testosterone result in virilization ("penis-at-twelve" syndrome). If discovered early, a male gender assignment can be supported with administration of dihydrotestosterone to increase penis size. If discovered after infancy, a female gender assignment can be supported with estrogen substitution therapy and prophylactic orchiectomy.
With complete androgen resistance, the external genitalia are feminized, but neither the male-type nor the female-type internal tracts develop. In the absence of the androgen receptor, the Wolffian ducts will degenerate. The Mullerian ducts will also degenerate because of the normal effect of testicular Mullerian regression factor.
With 17a-hydroxylase deficiency, the testes cannot synthesize testosterone, resulting in feminization of the external genitalia and degeneration of the Wolffian ducts. Normal secretion of Mullerian regression factor should also cause the degeneration of the Mullerian ducts. Because of the excessive secretion of deoxycorticosterone by the adrenal cortex, these individuals are usually hypertensive.
The Sertoli-only syndrome refers to the situation in which only the Sertoli cells of the seminiferous tubules are present (germinal cell aplasia). Spermatogenesis is absent in these individuals, who also show increased plasma levels of FSH because of decreased Sertoli cell secretion of inhibin. They may exhibit both male-type and female-type internal tracts because of the absence of Mullerian regression factor. The Leydig cells, however, have normal function and result in normal secretion of testosterone, so that both male-type internal tracts and external genitalia develop.
Testicular dysgenesis results in poor in utero development of the testes with concomitantly decreased secretion of testosterone and Mullerian regression factor. The Wolffian duct structures may degenerate, and the external genitalia may be feminized. Female-type internal tracts may develop because of the decreased secretion of Mullerian regression factor.
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| docarchana
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in sertoli only syndrome - both male & female internal tracts and
male external genitalia r present. right???????/
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| Lim
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yes,it is.
but if there are sertoli cells,it secretes MIF,which apoptoses mullerian internal organ,isn't it?
Edited by Lim on 09/04/06 - 08:23 PM
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| docarchana
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now its confusing.. if MIF is present. how can female internal organs develop?
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| new_n_lost
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Sertoli Cell Only Syndrome does not have lack of MIF its completely different disease n a cause of infertility. here the link http://www.emedicine.com/med/topic2104.htm
where as in 5 alpha Reductase Deficiency the ducts r present n the MIF is there but in variant amounts. here r 2 links which helped me understand http://www.emedicine.com/PED/topic1492.html + http://www.emedicine.com/ped/topic1980.htm
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