Gonadal dysgenesis
| Gonadal dysgenesis | |
|---|---|
| Specialty | Medical genetics  |
| Diagnostic method | pelvic examination (checking for maturation of external internal genitals), general examination (looking for secondary sexual characters), chromosome karyotyping, hormone levels like FSH, LH (which are increased in case of purely XX dysgenesis), family history |
| Intersex topics |
|---|
 |
Gonadal dysgenesis is classified as any congenital developmental disorder of the reproductive system[1] in humans. It is atypical development of
Gonadal development is a process, which is primarily controlled genetically by the chromosomal sex (
Differentiation of the gonads requires a tightly regulated cascade of genetic, molecular and morphogenic events.[5] At the formation of the developed gonad,
Gonadal dysgenesis arises from a difference in signalling in this tightly regulated process during early
Manifestations of gonadal dysgenesis are dependent on the
Causes
- Pure gonadal dysgenesis 46,XX also known as XX gonadal dysgenesis
- Pure gonadal dysgenesis 46,XY also known as XY gonadal dysgenesis
- Mixed gonadal dysgenesis also known as partial gonadal dysgenesis, and 45,X/46,XY mosaicism
- 45,Xor 45,X0
- Endocrine disruptions
Pathogenesis
46,XX gonadal dysgenesis
FSH and LH are secreted at elevated levels.
46,XX gonadal dysgenesis can manifest from a variety of causes.
46,XY gonadal dysgenesis
46,XY gonadal dysgenesis is characteristic of
The
Genital Undermasculinization is the technical term for partial of complete
Full undermasculinization results in a fully developed vulva with testicles inside the body where the ovaries usually are, which is caused by conditions such as complete androgen insensitivity syndrome. In 5α-Reductase 2 deficiency, individuals are born with normal female genitalia, however, during puberty, male differentiation and spermatogenesis occurs. Partial genital undermasculinization can occur if the body has a partial resistance to androgens, or if genital development is blocked, undermasculization can also be induced by certain drugs and hormones. The overall intensity of undermasculinization can manifest itself in hypospadias. The surgical assignment of newborns with ambiguous genitalia to a binary sex for cosmetic purposes is considered a human rights violation.[16][17]
SRY acts on gene SOX9 which drives Sertoli cell formation and testis differentiation.[18] An absence in SRY causes SOX9 to not be expressed at the usual time or concentration, leading to a decreased testosterone and anti-Müllerian hormone production.[4]
Lowered levels of testosterone and anti-Müllerian hormone disrupts the development of
Gonadal streaks can replace the tissues of testes, resembling ovarian stroma absent of follicles.[14] 46,XY gonadal dysgenesis can remain unsuspected until delayed pubertal development is observed.[14] Approximately 15% of cases of 46,XY gonadal dysgenesis carry de novo mutations in the SRY gene,[19] with an unknown causation for the remaining portion of 46,XY gonadal dysgenesis persons.[18]
Mixed gonadal dysgenesis
Mixed gonadal dysgenesis, also known as
The degree of development of the male reproductive tract is determined by the ratio of germ line cells expressing the XY genotype.[18][20]
Manifestations of
The
Mixed gonadal dysgenesis is poorly understood at the molecular level.
Turner syndrome
Turner syndrome, also known as 45,X or 45,X0, is a chromosomal abnormality characterised by a partial or completely missing second X chromosome,[4][21][22] giving a chromosomal count of 45, instead of the typical count of 46 chromosomes.[21]
Dysregulation in
The
Endocrine disruptions
Diagnosis
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Management
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History
Turner syndrome was first described independently by Otto Ulrich in 1930 and Henry Turner in 1938.[26] 46,XX pure gonadal dysgenesis was first reported in 1960.[26] 46,XY pure gonadal dysgenesis, also known as Swyer syndrome, was first described by Gim Swyer in 1955.[26]
See also
- (DoDI) 6130.03, 2018, section 5, 13f and 14m
- Ovotestis
- 46 XX
References
- .
- )
- ^ "Gonadal Streak. Farlex Partner Medical Dictionary".
- ^ a b c d e f g h i j k Balsamo A, Buonocore G, Bracci R, Weindling M (2012). "Disorders of Sexual Development". Neonatology. Springer.
- ^ ISBN 978-3-662-54254-5.
- ^ PMID 26653403.
- ^ PMID 26410164.
- PMID 1909490.
- ^ ISBN 978-3-540-78355-8.
- ^ PMID 27307783.
- S2CID 14748261.
- ^ PMID 16580399.
- PMID 29378665.
- ^ PMID 21929773.
- PMID 10874632– via jmg.bmj.com.
- ^ "Variation in Sex Characteristics". www.healthit.gov.
- ^ Alice D. Dreger; April M. Herndon. "Progress and Politics in the intersex rights movement, Feminist theory in action" (PDF).
- ^ PMID 27300185.
- ^ PMID 26526145.
- ^ PMID 480090.
- ^ a b c "Turner Syndrome: Condition Information". Eunice Kennedy Shriver National Institute of Health and Human Development. 2012.
- ^ ISBN 9780323315258.
- ^ PMID 11844747.
- ^ "Endocrine Disruptors, National Institute of Environmental Health Sciences, 2013".
- ^ Robert S (2010). "Pesticide atrazine can turn male frogs into females". Berkeley News, University of California.
- ^ S2CID 20122694.
External links
| Authority control databases: National |
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