Mayer-Rokitansky-Kuster-Hauser Syndrome

Müllerian agenesis, also known as Mayer–Rokitansky–Küster–Hauser syndrome (MRKH) or vaginal agenesis, is a congenital malformation characterized by a failure of the Müllerian duct to develop, resulting in a missing uterus and variable degrees of vaginal hypoplasia of its upper portion. Müllerian agenesis (including absence of the uterus, cervix and/or vagina) is the cause in 15% of cases of primary amenorrhoea. Because most of the vagina does not develop from the Müllerian duct, instead developing from the urogenital sinus, along with the bladder and urethra, it is present even when the Müllerian duct is completely absent. Because ovaries do not develop from the Müllerian ducts, affected women might have normal secondary sexual characteristics but are infertile due to the lack of a functional uterus. However, motherhood is possible through use of gestational surrogates. Müllerian agenesis, also known as Mayer–Rokitansky–Küster–Hauser syndrome (MRKH) or vaginal agenesis, is a congenital malformation characterized by a failure of the Müllerian duct to develop, resulting in a missing uterus and variable degrees of vaginal hypoplasia of its upper portion. Müllerian agenesis (including absence of the uterus, cervix and/or vagina) is the cause in 15% of cases of primary amenorrhoea. Because most of the vagina does not develop from the Müllerian duct, instead developing from the urogenital sinus, along with the bladder and urethra, it is present even when the Müllerian duct is completely absent. Because ovaries do not develop from the Müllerian ducts, affected women might have normal secondary sexual characteristics but are infertile due to the lack of a functional uterus. However, motherhood is possible through use of gestational surrogates. Mayer–Rokitansky–Küster–Hauser syndrome is hypothesized to be a result of autosomal dominant inheritance with incomplete penetrance and variable expressivity, which contributes to the complexity involved in identifying of the underlying mechanisms causing the condition. Because of the variance in inheritance, penetrance and expressivity patterns, MRKH is subdivided into two types: type 1, in which only the structures developing from the Müllerian duct are affected (the upper vagina, cervix, and uterus), and type 2, where the same structures are affected, but is characterized by the additional malformations of other body systems most often including the renal and skeletal systems. MRKH type 2 includes MURCS (Müllerian Renal Cervical Somite). The majority of MRKH syndrome cases are characterized as sporadic, but familial cases have provided evidence that, at least for some patients, MRKH is an inherited disorder. The underlying causes of MRKH syndrome is still being investigated, but several causative genes have been studied for their possible association with the syndrome. Most of these studies have served to rule-out genes as causative factors in MRKH, but thus far, only WNT4 has been associated with MRKH with hyperandrogenism. Reports of MRKH syndrome can be traced back to Hippocrates (460 B.C.–377 B.C.). The medical eponym honors August Franz Josef Karl Mayer (1787–1865), Carl Freiherr von Rokitansky (1804–1878), Hermann Küster (1879–1964) and Georges Andre Hauser (1921–2009). An individual with this condition is hormonally normal; that is, the person will enter puberty with development of secondary sexual characteristics including thelarche and pubarche (pubic hair). The person's karyotype will be 46,XX. At least one ovary is intact, if not both, 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, a person with MRKH cannot carry a pregnancy without intervention. It is possible for the person to have genetic offspring by in vitro fertilization (IVF) and surrogacy. Successful uterine transplant has been performed in limited numbers of patients, resulting in several live births, but the technique is not widespread or accessible to many women. A person with MRKH typically discovers 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. WNT4 (found on the short arm (p) of chromosome 1) has been clearly implicated in the atypical version of this disorder. A genetic mutation causes a leucine to proline residue substitution at amino acid position 12. This occurrence reduces the intranuclear levels of β catenin. In addition, it removes the inhibition of steroidogenic enzymes like 3β-hydroxysteriod dehydrogenase and 17α-hydroxylase. Patients therefore have androgen excess. Furthermore, without WNT4, the Müllerian duct is either deformed or absent. Female reproductive organs, such as the cervix, fallopian tubes, ovaries, and much of the vagina, are hence affected. An association with a deletion mutation in the long arm (q) of 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.