Complete androgen insensitivity syndrome | |
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Other names | Complete androgen resistance syndrome |
AIS results when the function of the androgen receptor (AR) is impaired. The AR protein (pictured) mediates the effects of androgens in the human body. | |
Specialty | Gynaecology, endocrinology |
Complete androgen insensitivity syndrome (CAIS) is an AIS condition that results in the complete inability of the cell to respond to androgens. [1] [2] [3] As such, the insensitivity to androgens is only clinically significant when it occurs in individuals who are exposed to significant amounts of testosterone at some point in their lives. [1] The unresponsiveness of the cell to the presence of androgenic hormones prevents the masculinization of male genitalia in the developing fetus, as well as the development of male secondary sexual characteristics at puberty, but does allow, without significant impairment, female genital and sexual development [3] [4] in those with the condition.
All human fetuses begin fetal development looking similar, with both the Müllerian duct system (female) and the Wolffian duct system (male) developing. Sex differentiation begins with the gonads, which in XX individuals become ovaries, and in XY individuals (including those with CAIS) typically become testicles due to the presence of the Y chromosome. It is at the seventh week of gestation that the bodies of non-CAIS individuals with the XY karyotype begin their masculinization: i.e., the Wolffian duct system is promoted and the Müllerian duct system is suppressed (the reverse happens with typically developing females). This process is triggered by androgens produced by the testicles. The bodies of unaffected XY individuals masculinize by, among other things, enlarging the genital tubercle into a penis, which in females becomes the clitoris, while what in females becomes the labia fuses to become the scrotum of males (where the testicles will later descend). [ citation needed ]
XY individuals affected by CAIS develop a normal external female habitus, despite the presence of a Y chromosome, [1] [5] [6] [7] [8] [9] but internally, they will lack a uterus, and the vaginal cavity will be shallow, while the gonads, which differentiated into testes in the earlier separate process also triggered by their Y chromosome, will remain undescended in the place. This results not only in infertility in individuals with CAIS, but also presents a risk of gonadal cancer later on in life. [10]
CAIS is one of the three categories of androgen insensitivity syndrome (AIS) since AIS is differentiated according to the degree of genital masculinization: complete androgen insensitivity syndrome (CAIS) when the external genitalia is that of a typical female, mild androgen insensitivity syndrome (MAIS) when the external genitalia is that of a typical male, and partial androgen insensitivity syndrome (PAIS) when the external genitalia is partially, but not fully masculinized. [1] [2] [5] [6] [7] [11] [12] [13] [14]
Androgen insensitivity syndrome is the largest single entity that leads to 46, XY undermasculinization. [15]
Individuals with complete androgen insensitivity syndrome (grades 6 and 7 on the Quigley scale) are born with an external female phenotype, without any signs of genital masculinization, despite having a 46,XY karyotype. [18] CAIS is usually recognized at puberty, [2] which may be slightly delayed, [19] but is otherwise normal except for absent menses and diminished or absent secondary terminal hair. [1] Axillary hair (i.e. armpit hair) fails to develop in one third of all cases. [20] The vulva is normal, although the labia and clitoris are sometimes underdeveloped. [21] [22] Vaginal depth varies widely for CAIS, but is typically shorter than normal; [1] one study of eight people with CAIS measured the average vaginal depth to be 5.9 cm [23] (vs. 11.1 ± 1.0 cm for unaffected women [24] ). In some extreme cases, the vagina has been reported to be aplastic (resembling a "dimple"), though the exact incidence of this is unknown. [25]
The gonads in people with CAIS are testes; during the embryonic stage of development, testes form in an androgen-independent process that occurs due to the influence of the SRY gene on the Y chromosome. [26] [27] They may be located intra-abdominally, at the internal inguinal ring, or may herniate into the labia majora, often leading to the discovery of the condition. [1] [28] [29] [30] Testes in those affected have been found to be atrophic upon gonadectomy. [31]
Testosterone produced by the testes cannot be directly used due to the mutant androgen receptor that characterizes CAIS; instead, it is aromatized into estrogen, which effectively feminizes the body and accounts for the normal female phenotype observed in CAIS. [1] However, up to 5% of individuals with CAIS do not have an AR mutation. [2] The receptor in question is encoded by the AR gene located on the X chromosome at Xq11–12. At least 15 different mutations were known in 2003, and they are all recessive, which makes the disease follow X-linked recessive inheritance. [20]
Immature sperm cells in the testes do not mature past an early stage, as sensitivity to androgens is required in order for spermatogenesis to complete. [32] [33] Germ cell malignancy risk, once thought to be relatively high, is now thought to be approximately 2%. [34] Wolffian structures (the epididymides, vasa deferentia, and seminal vesicles) are typically absent, but will develop at least partially in approximately 30% of cases, depending on which mutation is causing the CAIS. [35] The prostate, like the external male genitalia, cannot masculinize in the absence of androgen receptor function, and thus remains in the female form. [18] [36] [37] [38]
The Müllerian system typically regresses the same way it does in unaffected male fetuses due to anti-Müllerian hormone originating from the Sertoli cells of the testes. [19] Thus, people with CAIS, despite having a vagina due to androgen insensitivity, are born without fallopian tubes, a cervix, or a uterus, [19] and the vagina ends "blindly" in a pouch. [1] Müllerian regression does not fully complete in some cases of CAIS, resulting in Müllerian "remnants". [19] Although rare, a few cases of people diagnosed with CAIS and having Müllerian structures have been reported. In one exceptional case, a 22-year-old with CAIS was found to have a cervix, uterus, and fallopian tubes. [39] In an unrelated case, almost fully developed uterus was found in a 22-year-old adult with CAIS. [38]
Other subtle differences that have been reported include slightly longer limbs and larger hands and feet due to a proportionally greater stature than unaffected women, [40] [41] [42] larger teeth, [43] [44] minimal or no acne, [45] well developed breasts, [46] a greater incidence of meibomian gland dysfunction (i.e. dry eye syndromes and light sensitivity), [47] and dry skin and hair resulting from a lack of sebum production. [48]
Hormone levels have been reported in gonadally intact people with CAIS in a number of studies. [49] [50] Hormone levels are similar to those of males, including high testosterone levels and relatively low estradiol levels. [49] [50] However, luteinizing hormone (LH) levels are elevated while sex hormone-binding globulin (SHBG) levels are more consistent with those of females. [49] [50] [51] People with CAIS have low levels of progesterone similarly to males. [52] [53] [54] The production rates of testosterone, estradiol, and estrone have been reported to be higher in gonadally intact with CAIS than in men. [55] [56]
Study | Location | n | Age (years) | LH (IU/L) | FSH (IU/L) | T (ng/dL) | DHT (ng/dL) | E2 (pg/mL) | P4 (ng/mL) | SHBG (nmol/L) |
---|---|---|---|---|---|---|---|---|---|---|
Schindler (1975) | Tübingen, DE | 4 | ? (17–22) | ?a | ?a | 1040 ± 300 | 79 ± 30 | 36.7 ± 7.1 | 0.06 ± 0.02 | ? |
Blumenthal (1982) | Johannesburg, ZA | 4 | 19 (18–28) | 70 (8–97) | 14 (6–22) | 1356 (1240–1577) | ? | 40 (26–79) | 0.96 (0.68–1.76) | ? |
Melo (2003) | Sao Paulo, BR | 8 | 16.5 (14–34) | 26 (14–43) | 7.4 (3.5–16) | 346 (173–1040) | ? | 30 (22–40) | ? | ? |
Audi (2010) | Barcelona, ES | 11 | 20 (13.5–40) | 10 (<0.1–35) | 2.3 (0.4–23.4) | 576 (144–1350) | ? | 33 (20–73) | ? | 52 (22–128) |
Doehnert (2015) | Lübeck, DE/Pisa, IT | 42 | 17.3 (14–50) | 18.5 (5.5–51.1) | 3.5 (0.4–16.3) | 576 (173–1450) | ? | 31 (5–70) | ? | 53 (15–99) |
King (2017) | London, UK | 31 | 19.7 (13.4–52.3) | 24.2 (13–59.1) | 4.6 (1.1–68.9) | 640 (233–1260) | ? | 35 (12–63) | ? | ? |
Male ref. range | – | – | Adult | 1–10 | 1–7 | 346 (202–1010) | ? | 30 (10–50) | <0.6 | 10–50 |
Female ref. range | – | – | Adult | 2–6.6 | 2–6.6 | 43 (20–86) | ? | 80 (10–395) | <3.2–25 | 30–90 |
Abbreviations: LH = Luteinizing hormone. FSH = Follicle-stimulating hormone. T = Testosterone. DHT = Dihydrotestosterone. E2 = Estradiol. P4 = Progesterone. SHBG = Sex hormone-binding globulin. Notes: Values are mean (range) or mean ± standard deviation. Footnotes:a = LH = 73.2 ± 9.2 ng LER 907/mL, FSH = 40.2 ± 20.0 ng LER 907/mL. Sources: See template. |
All forms of androgen insensitivity, including CAIS, are associated with infertility, though exceptions have been reported for both the mild and partial forms. [4] [5] [7] [57] [58] [59]
CAIS is associated with a decreased bone mineral density. [60] [61] [62] [63] [64] [65] Some have hypothesized that the decreased bone mineral density observed in women with CAIS is related to the timing of gonadectomy and inadequate estrogen supplementation. [64] However, recent studies show that bone mineral density is similar whether gonadectomy occurs before or after puberty, and is decreased despite estrogen supplementation, leading some to hypothesize that the deficiency is directly attributable to the role of androgens in bone mineralization. [60] [61] [62] [63]
CAIS is also associated with an increased risk for gonadal tumors (e.g. germ cell malignancy) in adulthood if gonadectomy is not performed. [34] [66] [67] [68] The risk of malignant germ cell tumors in women with CAIS increases with age and has been estimated to be 3.6% at 25 years and 33% at 50 years. [68] The incidence of gonadal tumors in childhood is thought to be relatively low; a recent review of the medical literature [66] found that only three cases of malignant germ cell tumors in prepubescent girls have been reported in association with CAIS in the last 100 years. Some have estimated the incidence of germ cell malignancy to be as low as 0.8% before puberty. [1]
Vaginal hypoplasia, a relatively frequent finding in CAIS and some forms of PAIS, [23] [25] is associated with sexual difficulties including vaginal penetration difficulties and dyspareunia. [21] [25]
At least one study indicates that individuals with an DSD condition may be more prone to psychological difficulties, due at least in part to parental attitudes and behaviors, [69] and concludes that preventative long-term psychological counseling for parents as well as for affected individuals should be initiated at the time of diagnosis.
Lifespan is not thought to be affected by AIS. [1]
Despite the well-developed breasts in CAIS women, and for reasons that are not well-understood, breast cancer has never been reported in CAIS women and does not seem to occur or occurs only rarely. [70] [71] [72] [73] [74] [75] Only a case report of juvenile fibroadenoma exists. [70] [72] [76] A few cases of breast cancer have been reported in individuals with partial androgen insensitivity syndrome however. [73] [77] [78]
CAIS is usually not suspected until the menses fail to develop at puberty, or an inguinal hernia presents during premenarche. [1] [2] As many as 1–2% of prepubertal girls that present with an inguinal hernia will also have CAIS. [1] [19]
A diagnosis of CAIS or Swyer syndrome can be made in utero by comparing a karyotype obtained by amniocentesis with the external genitalia of the fetus during a prenatal ultrasound. [2] [80] Many infants with CAIS do not experience the normal, spontaneous neonatal testosterone surge, a fact which can be diagnostically exploited by obtaining baseline luteinizing hormone and testosterone measurements, followed by a human chorionic gonadotropin (hCG) stimulation test. [1]
The main differentials for CAIS are complete gonadal dysgenesis (Swyer syndrome) and Müllerian agenesis (Mayer-Rokitansky-Kuster-Hauser syndrome or MRKH). [1] [25] Both CAIS and Swyer syndrome are associated with a 46,XY karyotype, whereas MRKH is not; MRKH can thus be ruled out by checking for the presence of a Y chromosome, which can be done either by fluorescence in situ hybridization (FISH) analysis or on full karyotype. [1] Swyer syndrome is distinguished by the presence of a uterus, poor breast development and shorter stature. [1] The diagnosis of CAIS is confirmed when androgen receptor (AR) gene sequencing reveals a mutation, although up to 5% of individuals with CAIS do not have an AR mutation. [2]
Up until the 1990s, a CAIS diagnosis was often hidden from the affected individual, the individual's family, or both. [18] It is current practice to disclose the genotype at the time of diagnosis, particularly when the affected individual is at least of adolescent age. [18] If the affected individual is a child or infant, it is generally up to the parents, often in conjunction with a psychologist, to decide when to disclose the diagnosis. [18]
Management of AIS is currently limited to symptomatic management; methods to correct a malfunctioning androgen receptor protein that result from an AR gene mutation are not currently available. Areas of management include sex assignment, genitoplasty, gonadectomy in relation to tumor risk, hormone replacement therapy, and genetic and psychological counseling. Non-consensual interventions are still often performed, although general awareness on the resulting psychological traumatization is rising. [81]
Most individuals with CAIS are raised as females. [1] They are born with an external phenotype of a typical female and are thought to be usually heterosexual with a female gender identity; [41] [82] however, some research has suggested that individuals with CAIS are more likely to have more variable gender outcomes and a non-primarily heterosexual sexual orientation than relatively similar control groups of those with MRKH syndrome and PCOS, contradicting this belief. [83] At least two case studies have reported male gender identity in individuals with CAIS. [82] [84]
Most cases of vaginal hypoplasia associated with CAIS can be corrected using non-surgical pressure dilation methods. [23] [25] The elastic nature of vaginal tissue, as demonstrated by its ability to accommodate the differences in size between a tampon, a penis, and a baby's head, [85] make dilation possible even in cases when the vaginal depth is significantly compromised. [23] [25] Treatment compliance is thought to be critical to achieve satisfactory results. [21] [23] [25] Dilation can also be achieved via the Vecchietti procedure, which stretches vaginal tissues into a functional vagina using a traction device that is anchored to the abdominal wall, subperitoneal sutures, and a mold that is placed against the vaginal dimple. [25] Vaginal stretching occurs by increasing the tension on the sutures, which is performed daily. [25] The non-operative pressure dilation method is currently recommended as the first choice, since it is non-invasive, and highly successful. [25] Vaginal dilation should not be performed before puberty. [34]
While it was often recommended that women with CAIS eventually undergo gonadectomy to mitigate cancer risk, [1] there are differing opinions regarding the necessity and timing of gonadectomy. [86] The risk of malignant germ cell tumors with CAIS increases with age and has been estimated to be 3.6% at 25 years and 33% at 50 years. [68] However, only three cases of malignant germ cell tumors in prepubescent girls with CAIS have been reported in the last 100 years. [66] The youngest of these children was 14 years old. [87] Individuals with CAIS naturally go through puberty via the aromatization of testosterone into estrogens. Therefore, removal of the gonads will result in an individual requiring hormone replacement therapy. Gonadectomy is generally not recommended before puberty to allow for puberty to occur spontaneously. [88] [89] [90] Some individuals with CAIS may choose to go on testosterone HRT rather than estrogen. Research suggests that testosterone is at least as beneficial as estrogen replacement therapy and possibly improves outcomes in certain areas of well-being. [91]
If gonadectomy is performed early, then puberty must be artificially induced using gradually increasing doses of estrogen. [1] If gonadectomy is performed late, then puberty will occur on its own, due to the aromatization of testosterone into estrogen. [1] At least one organization, the Australasian Paediatric Endocrine Group, classifies the cancer risk associated with CAIS as low enough to recommend against gonadectomy, although it warns that the cancer risk is still elevated above the general population, and that ongoing cancer monitoring is essential. [86] Some choose to perform gonadectomy if and when inguinal hernia presents. [1] Estrogen replacement therapy is critical to minimize bone mineral density deficiencies later in life. [62] [64]
Some individuals with CAIS may choose to retain their gonads. If this is the case, annual imaging of the gonads via MRI or ultrasound is recommended in order to monitor for signs of malignancy. [92] Diagnostic laparoscopy and biopsy are also to be considered if imaging is ambiguous.
Some have hypothesized that supraphysiological levels of estrogen may reduce the diminished bone mineral density associated with CAIS. [62] Data has been published that suggests affected women who were not compliant with estrogen replacement therapy, or who had a lapse in estrogen replacement, experienced a more significant loss of bone mineral density. [61] [62] Progestin replacement therapy is usually seldom initiated as well. [1] Androgen replacement has been reported to increase a sense of well-being in gonadectomized people with CAIS, although the mechanism by which this benefit is achieved is not well understood. [1]
It is no longer common practice to hide a diagnosis of CAIS from the affected individual or her family. [18] Parents of children with CAIS need considerable support in planning and implementing disclosure for their child once the diagnosis has been established. [1] [18] For parents with young children, information disclosure is an ongoing, collaborative process requiring an individualized approach that evolves in concordance with the child's cognitive and psychological development. [1] In all cases, the assistance of a psychologist experienced in the subject is recommended. [1] [18]
Many surgical procedures have been developed to create a neovagina, but none of them are ideal. [25] Surgical intervention should only be considered after non-surgical pressure dilation methods have failed to produce a satisfactory result. [25] Neovaginoplasty can be performed using skin grafts, a segment of bowel, ileum, peritoneum, an absorbable adhesion barrier (Intercede, made by Johnson & Johnson), [93] [94] buccal mucosa, amnion, dura mater. [25] [95] [96] or with the support of vaginal stents/expanders. [97] [98] Success of such methods should be determined by sexual function, and not just by vaginal length, as has been done in the past. [96] Ileal or cecal segments may be problematic because of a shorter mesentery, which may produce tension on the neovagina, leading to stenosis. [96] The sigmoid neovagina is thought to be self-lubricating, without the excess mucus production associated with segments of small bowel. [96] Vaginoplasty may create scarring at the introitus (the vaginal opening), which requires additional surgery to correct. Vaginal dilators are required postoperatively to prevent vaginal stenosis from scarring. [23] [25] Inflatable vaginal stents are placed in the vagina deflated and then gently inflated. [99] Other complications include bladder and bowel injuries. [25] Yearly exams are required as neovaginoplasty carries a risk of carcinoma, [25] although carcinoma of the neovagina is uncommon. [95] [96] Neither neovaginoplasty nor vaginal dilation should be performed before puberty. [25] [34]
Challenges presented to people affected by this condition include: psychologically coming to terms with the condition, difficulties with sexual function, infertility. Long-term studies indicate that with appropriate medical and psychological treatment, those with CAIS can be satisfied with their sexual function and psychosexual development. [41] Individuals with condition can lead active lives and expect a normal lifespan.
It is estimated that CAIS occurs in 1 in 20,400 to 1 in 99,000 individuals with a 46,XY karyotype. [100] [101]
Historically, CAIS has been referred to in the literature under a number of other names, including testicular feminization [syndrome] (deprecated) and Morris syndrome. [102] [103] PAIS has also been referred to as Reifenstein syndrome, which should not be confused with CAIS. [102] [103]
The first definitive description of CAIS was reported in 1817. [104] [105] The condition became more widely known after it was reviewed and named testicular feminization by American gynecologist John McLean Morris in 1953. [105]
Androgen insensitivity syndrome (AIS) is a condition involving the inability to respond to androgens, typically due to androgen receptor dysfunction.
An androgen is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes the embryological development of the primary male sex organs, and the development of male secondary sex characteristics at puberty. Androgens are synthesized in the testes, the ovaries, and the adrenal glands.
XY complete gonadal dysgenesis, also known as Swyer syndrome, is a type of defect hypogonadism in a person whose karyotype is 46,XY. Though they typically have normal vulvas, the person has underdeveloped gonads, fibrous tissue termed "streak gonads", and if left untreated, will not experience puberty. The cause is a lack or inactivation of an SRY gene which is responsible for sexual differentiation. Pregnancy is sometimes possible in Swyer syndrome with assisted reproductive technology. The phenotype is usually similar to Turner syndrome (45,X0) due to a lack of X inactivation. The typical medical treatment is hormone replacement therapy. The syndrome was named after Gerald Swyer, an endocrinologist based in London.
Lipoid congenital adrenal hyperplasia is an endocrine disorder that is an uncommon and potentially lethal form of congenital adrenal hyperplasia (CAH). It arises from defects in the earliest stages of steroid hormone synthesis: the transport of cholesterol into the mitochondria and the conversion of cholesterol to pregnenolone—the first step in the synthesis of all steroid hormones. Lipoid CAH causes mineralocorticoid deficiency in affected infants and children. Male infants are severely undervirilized causing their external genitalia to look feminine. The adrenals are large and filled with lipid globules derived from cholesterol.
Isolated hypogonadotropic hypogonadism (IHH), also called idiopathic or congenital hypogonadotropic hypogonadism (CHH), as well as isolated or congenital gonadotropin-releasing hormone deficiency (IGD), is a condition which results in a small subset of cases of hypogonadotropic hypogonadism (HH) due to deficiency in or insensitivity to gonadotropin-releasing hormone (GnRH) where the function and anatomy of the anterior pituitary is otherwise normal and secondary causes of HH are not present.
Hypoestrogenism, or estrogen deficiency, refers to a lower than normal level of estrogen. It is an umbrella term used to describe estrogen deficiency in various conditions. Estrogen deficiency is also associated with an increased risk of cardiovascular disease, and has been linked to diseases like urinary tract infections and osteoporosis.
Familial male-limited precocious puberty, often abbreviated as FMPP, also known as familial sexual precocity or gonadotropin-independent testotoxicosis, is a form of gonadotropin-independent precocious puberty in which boys experience early onset and progression of puberty. Signs of puberty can develop as early as an age of 1 year.
Gonadal dysgenesis is classified as any congenital developmental disorder of the reproductive system characterized by a progressive loss of primordial germ cells on the developing gonads of an embryo. One type of gonadal dysgenesis is the development of functionless, fibrous tissue, termed streak gonads, instead of reproductive tissue. Streak gonads are a form of aplasia, resulting in hormonal failure that manifests as sexual infantism and infertility, with no initiation of puberty and secondary sex characteristics.
Partial androgen insensitivity syndrome (PAIS) is a condition that results in the partial inability of the cell to respond to androgens. It is an X linked recessive condition. The partial unresponsiveness of the cell to the presence of androgenic hormones impairs the masculinization of male genitalia in the developing fetus, as well as the development of male secondary sexual characteristics at puberty, but does not significantly impair female genital or sexual development. As such, the insensitivity to androgens is clinically significant only when it occurs in individuals with a Y chromosome. Clinical features include ambiguous genitalia at birth and primary amenhorrhoea with clitoromegaly with inguinal masses. Müllerian structures are not present in the individual.
Estrogen insensitivity syndrome (EIS), or estrogen resistance, is a form of congenital estrogen deficiency or hypoestrogenism which is caused by a defective estrogen receptor (ER) – specifically, the estrogen receptor alpha (ERα) – that results in an inability of estrogen to mediate its biological effects in the body. Congenital estrogen deficiency can alternatively be caused by a defect in aromatase, the enzyme responsible for the biosynthesis of estrogens, a condition which is referred to as aromatase deficiency and is similar in symptomatology to EIS.
The human gene SRD5A2 encodes the 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme, also known as 5α-reductase type 2 (5αR2), one of three isozymes of 5α-reductase.
Aromatase deficiency is a rare condition characterized by extremely low levels or complete absence of the enzyme aromatase activity in the body. It is an autosomal recessive disease resulting from various mutations of gene CYP19 (P450arom) which can lead to ambiguous genitalia and delayed puberty in females, continued linear growth into adulthood and osteoporosis in males and virilization in pregnant mothers. As of 2020, fewer than 15 cases have been identified in genetically male individuals and at least 30 cases in genetically female individuals.
Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life.
Mild androgen insensitivity syndrome (MAIS) is an intersex variation that results in a mild impairment of the cell's ability to respond to androgens. The degree of impairment is sufficient to impair spermatogenesis and / or the development of secondary sexual characteristics at puberty in males, but does not affect genital differentiation or development. Female genital and sexual development is not significantly affected by the insensitivity to androgens; as such, MAIS is only diagnosed in males. The clinical phenotype associated with MAIS is a normal male habitus with mild spermatogenic defect and / or reduced secondary terminal hair.
Hypergonadotropic hypogonadism (HH), also known as primary or peripheral/gonadal hypogonadism or primary gonadal failure, is a condition which is characterized by hypogonadism which is due to an impaired response of the gonads to the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and in turn a lack of sex steroid production. As compensation and the lack of negative feedback, gonadotropin levels are elevated. Individuals with HH have an intact and functioning hypothalamus and pituitary glands so they are still able to produce FSH and LH. HH may present as either congenital or acquired, but the majority of cases are of the former nature. HH can be treated with hormone replacement therapy.
Leydig cell hypoplasia (LCH), also known as Leydig cell agenesis, is a rare autosomal recessive genetic and endocrine syndrome affecting an estimated 1 in 1,000,000 individuals with XY chromosomes. It is characterized by an inability of the body to respond to luteinizing hormone (LH), a gonadotropin which is normally responsible for signaling Leydig cells of the testicles to produce testosterone and other androgen sex hormones. The condition manifests itself as pseudohermaphroditism, hypergonadotropic hypogonadism, reduced or absent puberty, and infertility.
Hormonal breast enhancement or augmentation is a highly experimental potential medical treatment for the breasts in which hormones or hormonal agents such as estrogen, progesterone, growth hormone (GH), and insulin-like growth factor 1 (IGF-1) are utilized or manipulated to produce breast enlargement in women. It is a possible alternative or supplement to surgical breast augmentation with breast implants or fat transfer and other means of medical breast enlargement.
Hypergonadotropic hypergonadism is an endocrine situation and subtype of hypergonadism in which both gonadotropin levels and gonadal function, such as sex hormone production, are abnormally high. It can be associated with hyperandrogenism and hyperestrogenism and with gonadal cysts and tumors. It can be caused by medications such as gonadotropins, gonadotropin-releasing hormone agonists, nonsteroidal antiandrogens, and selective estrogen receptor modulators, as well as conditions like human chorionic gonadotropin-secreting tumors, complete androgen insensitivity syndrome, and estrogen insensitivity syndrome.
The pharmacology of estradiol, an estrogen medication and naturally occurring steroid hormone, concerns its pharmacodynamics, pharmacokinetics, and various routes of administration.
The estrogen provocation test, also known as the estrogen stimulation test or estrogen challenge test, is a diagnostic procedure used to evaluate the function of the hypothalamic–pituitary–gonadal axis. It involves the administration of a large amount of estrogen, resulting in estrogenic exposure similar to or greater than normal preovulatory estradiol levels, in an attempt to induce a positive feedback surge in levels of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Estrogens that have been used in the estrogen provocation test include estradiol benzoate, estradiol valerate, ethinylestradiol, and high-dose transdermal estradiol patches. The test involves sustained estrogenic exposure equivalent to estradiol levels of 200 to 300 pg/mL or more for at least 50 hours and results in a surge in gonadotropin levels about 32 to 72 hours following initiation of estrogenic exposure. Levels of LH and FSH increase during the gonadotropin surge by about 10-fold and 4-fold, respectively.
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