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). Signs and symptoms
A female with this condition is hormonally normal; that is, the woman will enter puberty with development of secondary sexual characteristics including thelarche and pubarche (pubic hair). The womans 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 woman with MRKH cannot carry a pregnancy without intervention. It is possible for the woman to have genetic offspring by in vitro fertilization (IVF) and surrogacy.
Genome
The HSV genome spans about 150,000 bp and consists of two unique segments, named unique long (UL) and unique short (US), as well as terminal inverted repeats found to the two ends of them named repeat long (RL) and repeat short (RS). There are also minor "terminal redundancy" (α) elements found on the further ends of RS. The overall arrangement is RL-UL-RL-α-RS-US-RS-α with each pair of repeats inverting each other. The whole sequence is then encapsuled in a terminal direct repeat. The long and short parts each have their own origins of replication, with OriL located between UL28 and UL30 and OriS located in a pair near the RS. As the L and S segments can be assembled in any direction, they can be inverted relative to each other freely, forming various linear isomers. Gene expression
HSV genes are expressed in 3 temporal classes: immediate early (IE or α), early (E or ß) and late (γ) genes. However, the progression of viral gene expression is rather gradual than in clearly distinct stages. Immediate early genes are transcribed right after infection and their gene products activate transcription of the early genes. Early gene products help to replicate the viral DNA. Viral DNA replication, in turn, stimulates the expression of the late genes, encoding the structural proteins.Transcription of the immediate early (IE) genes begins right after virus DNA enters the nucleus. All virus genes are transcribed by host RNA polymerase II. Although host proteins are sufficient for virus transcription, viral proteins are necessary for the transcription of certain genes.