出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/10/22 23:18:12」(JST)
| Müllerian agenesis | |
|---|---|
| Classification and external resources | |
| ICD-10 | Q51.0, Q52.0 |
| ICD-9 | 626.0 |
| OMIM | 158330 |
| DiseasesDB | 8390 |
Müllerian agenesis is a congenital malformation characterised by a failure of the müllerian ducts to develop, resulting in a missing uterus and fallopian tubes and variable malformations of the upper portion of the vagina. It is the second most common cause of primary amenorrhoea after gonadal failure (such as from Turner syndrome). The condition is also called MRKH or Mayer-Rokitansky-Küster-Hauser Syndrome, named after August Franz Joseph Karl Mayer, Carl Freiherr von Rokitansky, Hermann Küster, and G. A. Hauser.
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An individual with this condition is hormonally normal; that is, they will enter puberty with development of secondary sexual characteristics including thelarche and adrenarche (pubic hair). Their chromosome constellation will be 46,XX. Ovaries are intact and ovulation usually occurs. Typically, the vagina is shortened and intercourse may, in some cases, be difficult and painful. Medical examination supported by gynecologic ultrasonography demonstrates a complete or partial absence of the cervix, uterus, and vagina.
If there is no uterus, people with MRKH cannot carry a pregnancy. However, it is possible for them to have genetic offspring by in vitro fertilisation (IVF) and surrogacy. Treatment by uterine transplantation is still in its infancy.[1]
People with MRKH typically discover the condition when, during puberty years, the menstrual cycle does not start (primary amenorrhoea). Some find out earlier through surgeries for other conditions, such as a hernia.
There are two forms of MRKH. One is associated with the absence of just the vagina and uterus, while the other affects additional parts of the body, too. Of those suffering from the latter form, 40% will have kidney abnormalities (15% of these individuals will be born with only one kidney), 10% will have hearing problems, and 10-12% will have skeletal abnormalities.[2]
MRKH is caused by heterozygous mutation of the WNT4 gene on chromosome 1p36.[3] This gene is responsible for, among other things, the development of the Paramesonephric duct, the embryonic precursor to female reproductive organs, such as the cervix, Fallopian tubes, ovaries, and much of the vagina.[4] Without the WNT4 gene, the Müllerian duct is either deformed or absent, meaning that it never develops into the female reproductive organs.
An association with a deletion mutation in chromosome 17 (17q12) has been reported. The gene LHX1 is located in this region and may be the cause of a number of these cases.[5]
The estimated prevalence is 1 in 5000 people with XX chromosomes.[citation needed] Queen Amalia of Greece was found post mortem to have had the syndrome.[citation needed] Her inability to provide an heir contributed to the overthrow of her husband, King Otto of Greece.[citation needed]
Although there are treatments to increase the comfort in sexual intercourse, there are none that can make pregnancy possible. There are plans by UK and Swedish doctors for a uterine transplant that would allow these women to carry their own child, but no transplant has yet been successful in producing a child. Since ovaries are present, people with this condition can have genetic children through IVF with embryo transfer to a gestational carrier. Some also choose to adopt.
It may be necessary to use vaginal dilators or surgery to develop a functioning vagina to allow for penetrative sexual intercourse. A number of surgical approaches have been used. In the McIndoe procedure[6] a skin graft is applied to form an artificial vagina. After the surgery, dilators are still necessary to prevent vaginal stenosis. The Vecchietti procedure has been shown to result in a vagina that is comparable to a normal vagina in patients with Müllerian agenesis.[7][8] In the Vecchietti procedure, a small plastic “olive” is threaded against the vaginal area, and the threads are drawn through the vaginal skin, up through the abdomen and through the navel using laparoscopic surgery. There the threads are attached to a traction device. The operation takes about 45 minutes. The traction device is then tightened daily so the olive is pulled inwards and stretches the vagina by approximately 1 cm per day, creating a vagina approximately 7 cm deep in 7 days, although it can be more than this.[9]
Emotional help is available in various support groups across the internet.
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| リンク元 | 「ロキタンスキー・キュスター・ハウザー症候群」 |
| 関連記事 | 「syndrome」 |