Leydig Cell Hypoplasia
November 3, 2007 on 7:25 am | In Gynecology | Comments OffJoe Leigh Simpson
In complete absence of Leydig cells, 46,XY cases have female external genitalia, no uterus, and bilateral testes devoid of Leydig cells. Epididymides and vasa deferentia are present, and serum LH is elevated. Affected siblings have been reported and parental consanguinity observed. Thus, autosomal recessive inheritance has long been accepted.
The molecular basis involves mutation [...]
Agonadia (Testicular Regression Syndrome)
November 3, 2007 on 7:15 am | In Gynecology | Comments OffJoe Leigh Simpson
In agonadia, gonads are absent, external genitalia are normal, and all but rudimentary müllerian or wolffian derivatives are absent. External genitalia usually consist of a phallus about the size of a clitoris, underdeveloped labia majora, and nearly complete labioscrotal fusion. Persistent urogenital sinus often is present. By definition, gonads are undetectable. Neither normal [...]
Estrogen Receptor Defects
November 3, 2007 on 7:12 am | In Gynecology | Comments OffJoe Leigh Simpson
The estrogen receptor gene consists of eight exons and is coded on chromosome 6q24®27. Analogous to the androgen receptor gene, there is a DNA-binding region (exons 2 and 3) and an estrogen-binding domain (exons 4 though 8).
An estrogen receptor mutation was found by Lubahn in a 28-year-old man who showed normal male sexual [...]
Aromatase Mutations
November 3, 2007 on 7:11 am | In Gynecology | Comments OffJoe Leigh Simpson
Conversion of androgens (D4-androstenedione) to estrogens (estrone) requires cytochrome P450 aromatase, an enzyme that is the gene product of a single 40-kb gene located on chromosome 15q21.1. The gene consists of ten exons. Although Ito reported a mutation in this CYP19 (P450 arom) gene in a 18-year-old 46,XX woman with primary amenorrhea and [...]
Complete Androgen Insensitivity
November 1, 2007 on 11:50 am | In Gynecology | Comments OffJoe Leigh Simpson
In complete androgen insensitivity (CAI; or complete testicular feminization), 46,XY individuals show bilateral testes, female external genitalia, a blindly ending vagina, and no müllerian derivatives. These findings are entirely predictable, given the underlying pathogenesis involving inability to respond to testosterone. AMH is synthesized, as in the normal testis. The body responds normally to [...]
3b-Hydroxysteroid Dehydrogenase
October 30, 2007 on 10:23 am | In Gynecology | Comments OffJoe Leigh Simpson
This enzyme deficiency is inherited in autosomal recessive fashion. Decreased synthesis of both androgens and estrogens occurs . The major androgen produced is DHEA, as already discussed. DHEA is a weaker androgen than testosterone and as such is not capable of adequately virilizing the male fetus. Diagnosis usually is established on the basis [...]
Congenital Adrenal Lipoid Hyperplasia
October 30, 2007 on 10:21 am | In Gynecology | Comments OffJoe Leigh Simpson
In congenital adrenal lipoid hyperplasia, male pseudohermaphrodites show ambiguous or female-like external genitalia and severe sodium wasting. Adrenals are characterized by foamy-appearing cells filled with cholesterol. Accumulation of cholesterol has long indicated that cholesterol cannot be converted to pregnenolone. Inheritance has been presumed to be autosomal recessive on the basis of increased parental [...]
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