GenderDysphoria.fyi/public/en/chromosomes.md

date	title	linkTitle	description	preBody	classes	siblings	tweets
2020-01-26T20:41:55.827Z	Disorders of Sex Development: Gender is not Chromosomal	Chromosomes	DNA is more what you'd call guidelines than actual rules.	_disclaimer	gdb	prev prevCaption next nextCaption /en/causes Causes of Gender Dysphoria /en/hormones How Hormones Work	https://twitter.com/RebeccaRHelm/status/1207834357639139328 https://twitter.com/RebeccaRHelm/status/1207835110617309191 https://twitter.com/RebeccaRHelm/status/1207835384358604802 https://twitter.com/RebeccaRHelm/status/1207835597206937600 https://twitter.com/RebeccaRHelm/status/1207835815071473664 https://twitter.com/RebeccaRHelm/status/1207835999130259456 https://twitter.com/RebeccaRHelm/status/1207837155667718145 https://twitter.com/RebeccaRHelm/status/1207838570276372480 https://twitter.com/RebeccaRHelm/status/1207838924263084033 https://twitter.com/RebeccaRHelm/status/1207839452619522048 https://twitter.com/RebeccaRHelm/status/1207839986801922048 https://twitter.com/alicemiriel/status/1208181235593490433 https://twitter.com/TransEthics/status/1223942625708761088

But the Chromosomes!!!

{!{

{{import '~/tweet' ids=[ '1223942625708761088' ] tweets=meta.tweets className="" }}

}!}

There are dozens of ways that chromosomes can be much more complex than XX and XY. Referred to as DSDs (differences in sex development), not all of them result in an intersex condition, and many only manifest at the onset of puberty.

• De la Chapelle syndrome (46,XX Male) occurs when the SRY gene from the sperm parent crosses over into a non-Y-bearing sperm during spermatogenesis. When the egg and sperm merge, it results in an XX embryo with an SRY gene, creating a phenotypically-male child with two X chromosomes.

• Swyer syndrome (46,XY Female) produces a phenotypically-female child with an XY chromosome. This results from a dozen different genetic conditions, including:

  • Absence or defect of an SRY gene
  • Absence or defect of DHH synthesis
  • Absence of the SF-1 protein due to adrenal failure
  • Absence of or defect the CBX2 gene, preventing TDF cascade

• XX gonadal dysgenesis is very similar to Swyer syndrome, except it occurs in XX children and results in nonfunctional ovaries.

• Turner syndrome (45,X) produces a phenotypically-female child with numerous abnormalities. It occurs when neither an X or Y chromosome crosses over from the sperm.

• Klinefelter syndrome (47,XXY) results in a phenotypically-male child with more feminine traits. In extremely rare cases it appears in female-assigned children as well, resulting in feminized testicles instead of ovaries.

• 48,XXXY Klinefelter syndrome has similar results to 47,XXY Klinefelter syndrome, but with more intense health issues.

• 49,XXXXY Klinefelter syndrome is often fatal, but when it isn't, it often results in a sterile child.

• Trisomy X (47,XXX), Tetrasomy X (48,XXXX), and Pentasomy X (49,XXXXX) all result in a female child, but with progressively more intense health issues.

• XXYY Syndrome results in male children (due to two SRY genes) who often experience hypogonadism, needing testosterone supplements, but otherwise seeming like a typical male.

• Mosaicism results when some cells in the body have one set of chromosomes and other cells have another due to a mutation of the genome during gestation. This may be XX/XY (resulting in a dual set of genitalia), X/XY (a milder form of Swyer or Turner syndromes) or XX/XXY (a milder form of Klinefelter syndrome).

• Chimerism occurs when two fertilized embryos merge together into one zygote, causing half of the child to contain one set of DNA and the other half to contain another. This can result in an otherwise completely typical human being of either male or female phenotype, even capable of producing offspring, but which comes back on a karyotype test as not matching their phenotype based on where the sample was taken on their body. In extremely rare cases this can result in two full sets of reproductive organs.

• Congenital adrenal hyperplasia (CAH) is masculinization of the female genitals in an XX child due to overactive adrenal glands.

• Androgen insensitivity syndrome (AIS) is a total or partial resistance to all androgens, preventing masculinization of all organs, save for the testicles, in an XY child. AIS subjects typically develop a female gender identity, but some partial cases may be male.

• 5-alpha-reductase deficiency (5ARD) is a failure in the body's ability to metabolize testosterone into dihydrotestosterone (DHT), preventing masculinization of the genitalia until the onset of puberty, when the child suddenly grows a penis.

• Aromatase deficiency causes masculinization of an otherwise female child due to excess levels of testosterone (and can bleed over into the mother during gestation).

• Aromatase excess causes feminisation in an otherwise male child, as all testosterone is converted into estrogen.

{!{

{{import '/tweet' ids=[ '1207834357639139328' '1207835110617309191' '1207835384358604802' '1207835597206937600' '1207835815071473664' '1207835999130259456' '1207837155667718145' '1207838570276372480' '1207839986801922048' '1207838924263084033' '1207839452619522048' ] tweets=meta.tweets className="oneblock" }} {{import '/tweet' ids=[ '1208181235593490433' ] tweets=meta.tweets className="" }}

}!}