Sex Differentiation Disorders
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Abnormalities in sexual differentiation that may occur in the gonads, the genital tracts, and the external genitalia. Disorders of sexual differentiation are due to the presence or absence of genetic and endocrine factors. Sex-determining genes (GENE, SRY) dictate the gonadal sex whereas the fetal testicular hormones determine the somatic sex during SEX DIFFERENTIATION. |
| Notes: |
organic in nature: differentiate from SEX DISORDERS (related to coitus); DF: SEX DIFFER DIS |
Sex Differentiation Disorders Categories.
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Gonadal Dysgenesis - A number of syndromes with defective gonadal developments such as streak gonads and dysgenetic testes. The spectrum of gonadal and sexual abnormalities is reflected in their varied sex chromosome (SEX CHROMOSOMES) constitution as shown by the karyotypes of 45,X monosomy (TURNER SYNDROME); 46,XX (GONADAL DYSGENESIS, 46XX); 46,XY (GONADAL DYSGENESIS, 46,XY); and sex chromosome MOSAICISM (GONADAL DYSGENESIS, MIXED). Their phenotypes range from female, through ambiguous, to male. This concept includes gonadal agenesis. |
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Hermaphroditism - Originally, a state characterized by the presence of both male and female sex organs. In humans, true hermaphroditism is caused by anomalous differentiation of the gonads, with the presence of both ovarian and testicular tissue and of ambiguous morphologic criteria of sex. If only testicular tissue is present, but there are some female morphological criteria of sex, it is known as male PSEUDOHERMAPHRODITISM. If only ovarian tissue is present, but there are some male morphological criteria of sex, it is known as female PSEUDOHERMAPHRODITISM. (Dorland, 27th ed) |
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Kallmann Syndrome - Congenital and familial disorder characterized by hypogonadotropic hypogonadism, eunuchoidal features, and anosmia or hyposmia. It is caused by a defect in the synthesis and/or release of LHRH (luteinizing hormone-releasing hormone; GONADORELIN) from the hypothalamus as a result of faulty embryonic neuronal migration. The gene responsible for this is found in the region Xp22.3 on the short arm of the X chromosome. There is a homolog on the Y chromosome. The syndrome is more prevalent in males by a ratio of three to one. |
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Klinefelter Syndrome - A SEX CHROMOSOME DISORDER characterized by small testes, underdevelopment of secondary sexual characteristics, infertility (INFERTILITY, MALE), hyalinization and fibrosis of the seminiferous tubules, and elevated levels of gonadotropin. Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several variants include those with the karyotpes 48,XXYY; 48,XXXY; 49,XXXXY, and several mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.). |
Sex Differentiation Disorders Definitions and Terms
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