Complete androgen resistance
Complete androgen insensitivity syndrome or Goldberg-Maxwell Morris syndrome , English: Complete Androgen Insensitivity Syndrome or shortly CAIS is that today probably most apt name for a genetic receptor defect of the target cells for testosterone and a consequent female phenotype and a female social gender for male sex chromosomes pattern ( karyotype : 46, XY). There are fears that phenotypically similar clinical pictures could also be triggered by endocrine disruptors (xenohormones) such as bisphenol A.
Sometimes the appearance is also referred to with the terms testicular feminization , hairless woman syndrome (literally: "hairless woman syndrome") or pseudohermaphroditism masculinus internus (lat.), Which are usually unpleasant for those affected.
The term XY woman, which is also used for the clinical picture, can be misunderstood, as it can include other causes of a female appearance in a male karyotype in addition to the above-mentioned ones.
Although the gonads , which are initially still inside the body, are differentiated into testes , the peripheral testosterone resistance (the testosterone must bind to androgen receptors , but these do not react adequately) further differentiation into a male phenotype, which is dependent on an undisturbed testosterone effect, is interrupted and instead the formation the pseudo-female phenotype (if the male genotype persists). As a result, no male external genital can develop and the testicle subsequently remains inside the body or can maximally sink into the area of the groin or the large labia . For this reason, too, considering the primary consequence of the genetic defect, it is better to speak of complete androgen resistance (CAIS) today.
At birth there is usually nothing to indicate that the newborn is not a normally developed girl. Complete androgen resistance (CAIS) differs from incomplete androgen resistance (PAIS and MAIS = partial or minimal androgen resistance) primarily with regard to the development of social sex, so that a separate contribution is justified.
The non-androgen-dependent steps of sexual differentiation are still possible: The anti-Müllerian hormone (AMH) formed in the Sertoli cells of the embryonic testes causes a regression of the Müller ducts , which were initially present in both sexes , which in turn act as anchors for the uterus and fallopian tubes so that these organs are not formed. Since the anlage of the upper third of the vagina also comes from the Müller ducts, it is usually shortened and ends blind, as it cannot include a cervix . In individual cases, for reasons that have not yet been precisely understood, it can have considerable differences in length, even in siblings with complete androgen resistance, or it can be shortened to such an extent that, in extreme cases, surgical vaginal augmentation is necessary later to enable satisfactory sexual intercourse. Apart from that, the female development is undisturbed. The affected people develop outwardly feminine. The extent to which all organs are androgen-resistant has not yet been scientifically proven. The intelligence is average (to above average). In addition, the body size is often above average.
There is hypergonadotropic hypergonadism , which means that both gonadotropins (LH / FSH) from the anterior pituitary gland and testosterone levels are elevated. Normally, an increased testosterone level inhibits the release of gonadotropins (negative feedback mechanism). The receptor defect prevents this.
With the onset of puberty, there is a lack of underarm and pubic hair and the absence of menarche (the first menstrual period ). Since no uterus is created in xy-chromosomal people (exception xy-chromosomal Swyer syndrome , due to the lack of SRY ), neither a primary nor a secondary amenorrhea can be present. Less obvious, but no less typical, is that people with complete androgen resistance do not develop acne .
In childhood, the diagnosis is usually based on a lump or bulge in the labia majora or groin, which is an undescended testicle (inguinal testicle ) or an inguinal hernia and a testicle found in the hernial sac. During or after puberty, a lack of secondary hair, the lack of menstruation (because there is no uterus) or an unfulfilled desire to have children lead to clarification, whereby the suspected diagnosis is made using ultrasound. To confirm the diagnosis, a blood sample is taken to create a karyogram (CAIS have an XY chromosome set just like PAIS and MAIS).
There is no causal (i.e., related to the genetic defect) therapy. Physical development may be supported with estrogens , but estrogens are often used to enable further sexual development with the onset of puberty, if the testes were removed before puberty if diagnosed early. According to some doctors, the latter should happen before the age of 20, as the testes in the abdomen are exposed to a relatively high ambient temperature and there is therefore an increased risk of degeneration of about 25%.
The body of a person with CAIS is able to use the hormone in its own testicles to create the necessary substances for appropriate physical and mental development and maintenance. This is supported by the fact that people with CAIS, although they do not menstruate because of the lack of a uterus and testicles instead of ovaries , still have an adult outwardly feminine body and breast growth. Large amounts of estrogen, however, are alien to this body. Nevertheless, the indication of orchiectomy should be considered in the case of a maldescensus testis, as there is a potential risk of dysplasia of the testes. The subsequent administration of estradiol also lowers the risk of osteoporosis, has a protective effect on the skin and hair and promotes the feminine appearance. Hormone replacement therapy with testosterone is not approved, but can provide the patient with CAIS with a supply of testosterone adapted to his or her original physical condition.
- Dadak, C. (Ed.): Sexuality, reproduction, pregnancy, birth . 3. Edition. Facultas Verlags- und Buchhandels AG, Vienna 2010, ISBN 978-3-7089-0613-3 , p. 88 .