What Is Mayer Rokitansky Kuster Hauser Syndrome?

Mayer-Rokitansky-Küster-Hauser syndrome (MRKH syndrome) is a rare congenital disorder that causes women and people assigned female at birth (AFAB) to be born with a missing or underdeveloped upper vagina and/or uterus. The external genitalia, urethra, lower vagina, clitoris, labia, and vaginal opening, however, remain intact. 

Can people with MRKH syndrome ever have babies? What about menstrual periods? What causes MRKH syndrome, and is it treatable? Are you curious to have these questions (and much more!) answered? Keep reading! 

Introduction

Also referred to as ‘’congenital absence of the uterus and vagina’’ (CAUV), ‘’vaginal agenesis’’, ‘’Müllerian agenesis’’, ‘’Müllerian aplasia’’ (MA), and ‘’genital renal ear syndrome’’ (GRES), Mayer-Rokitansky-Küster-Hauser syndrome (MRKH syndrome)¹ is a rare congenital disorder that causes some women and people assigned female at birth (AFAB) to be born with an upper vagina and/or uterus that are either underdeveloped or fully absent. As a result, affected individuals do not have menstrual cycle (‘’amenorrhea’’), experience extreme pain during sexual intercourse, and are unable to carry out normal pregnancies without medical help.

Despite the absence of the uterus and/or upper vagina, women and people AFAB with MRKH syndrome have a normal female karyotype (chromosome pattern) (46, XX) and, therefore, develop the typical female sex secondary characteristics including growing breasts, underarm and pubic hair, a lower vagina, vaginal opening, labia (lips of the vagina), and clitoris. They also have normal external genitalia, and most have fully functioning ovaries and fallopian tubes. Furthermore, the urethra in women and people who are AFAB remains intact, thus enabling them to pee normally. 

According to recent research studies, MRKH syndrome is extremely rare, affecting approximately 1 in 4,500-5,000 female infants.² However, more women and people  AFAB are likely affected by MRKH syndrome as it remains poorly investigated in research, and its prevalence differs largely across different populations. 

Understanding MRKH syndrome

A brief history of MRKH syndrome

Over 130 years, four scientists described MRKH syndrome, and hence each of their surnames forms a part of the disease’s name: German anatomist August Franz Josef Karl Mayer (1829), Austrian anatomist Carl von Rokitansky (1838), German gynaecologist Hermann Küster (1910) and Swiss gynaecologist Georges Andre Hauser (1961).²

Interestingly, the first person to ever describe MRKH syndrome was the Italian anatomist Realdo Colombo in 1562.² However, his descriptions were vague, and therefore the disease was not named after him. 

Causes and genetics

General Causes

• It is believed that the reproductive system is underdeveloped in women and people AFAB because their Müllerian ducts, which are essential for the development of the uterus, fallopian tubes, cervix, and upper vagina, do not develop fully during fetal development.² However, why and how this happens remains unclear to this day. 
• Scientists do not believe that environmental factors³ (at least not in isolation) cause MRKH syndrome, as no studies thus far have found any link between medication use and/or maternal illness during pregnancy and MRKH development. 

Genetic Factors

In contrast to environmental factors, it is believed that genes and chromosomes play a dominant role in the development of MRKH syndrome.²  However, to date, scientists have unfortunately not been able to find a specific gene which causes MRKH syndrome because every study so far has reported a unique genetic mutation in each patient. It is also interesting to note that the majority of cases reported with MRKH syndrome occur in people with no family history of the disease,² suggesting that genes are not the only factors driving MRKH syndrome and that other contributing factors are at play. 

Types of MRKH syndrome

MRKH syndrome is categorised into two broad types:¹ 

Type 1 MRKH Syndrome (‘’isolated’’ form)

Women and people AFAB with this type only have abnormalities in some reproductive organs, including the uterus, cervix, and/or upper vagina. However, their ovaries and fallopian tubes remain fully functional. 

Type 2 MRKH Syndrome (‘’atypical’’ form)

Women and people AFAB with this type have abnormalities in both their reproductive organs (upper vagina, uterus, cervix, ovaries, and fallopian tubes) and other organs, including the spine and/or kidneys. 

Clinical features

Primary characteristics

The main primary characteristics¹ of MRKH syndrome include:

• An absent or underdeveloped upper vagina 
• An absent or undeveloped uterus 

Secondary characteristics

The main secondary characteristics¹ of MRKH syndrome include: 

• Renal abnormalities: Recent studies suggest that renal abnormalities are the main secondary characteristic of MRKH syndrome, causing over 30-40% of European patients to be born with either one (‘’unilateral renal agenesis’’ (URA)) or two malfunctioning kidney/s or no kidneys at all.² 
• Skeletal abnormalities: These affect over 10-40% of patients with MRKH syndrome and occur due to improper spinal vertebrae development.²
• Hearing loss and heart defects: These affect less than 5% of people with Type 2 MRKH syndrome, as suggested by recent studies.² 

Distinguishing MRKH from other conditions

Complete androgen insensitivity syndrome (CAIS) (or ‘’Morris syndrome’’)

Similarly to MRKH syndrome, patients with CAIS fail to develop a functioning upper vagina and/or uterus and have normal breast and pubic hair development.² However, CAIS differs from MRKH syndrome in that the patients are male (46, XY), and have mutations in the androgen receptor gene, hence the name. 

Turner's syndrome 

Although patients with Turner’s syndrome and MRKH syndrome are both genetically female, lack menstrual periods, and have underdeveloped ovaries, patients with Turner’s syndrome have only one functioning X sex chromosome (45, X) in contrast to MRKH syndrome (46, XX).² Unlike MRKH syndrome, females with Turner’s syndrome also have a fully functioning uterus, cervix, and upper vagina.⁴

Diagnosis of MRKH syndrome

A healthcare provider will diagnose a suspected patient with MRKH syndrome by performing a series of tests¹ in the following order:

• Physical examination: During this first step, the healthcare provider will insert a gloved finger into the patient’s vagina to measure its width and depth
• Imaging techniques: If the patient’s vagina is discovered to be short and narrow, the healthcare provider will order imaging tests to see whether the uterus, fallopian tubes, and other organs, including the kidneys and spine, are affected. The main imaging tests that are used to diagnose MRKH syndrome include ultrasound and magnetic resonance imaging (MRI)
• Genetic and/or hormonal testing: Certain blood tests may be ordered to check hormone levels and/or whether any genetic mutations are present

The psychological impact of diagnosis

Unfortunately, because diagnosis is often given during adolescence, which is a period when people experience psychological and physical development, deep emotional changes, and greater vulnerability, upon receiving a diagnosis, many patients with MRKH syndrome struggle with identity, sexuality, infertility, low self-esteem, and mental health issues including anxiety and depression.²

Indeed, recent studies report four major psychological and psychosexual themes in people with MRKH syndrome:²

• Feelings of ‘’being different’’ 
• Feeling incapable of ‘’managing intimacy’’
• Feeling a ‘‘threat’’ to female identity 
• Feeling a loss of independence 

Current management and treatment of MRKH syndrome

At present, the most common management and treatment options¹ for MRKH syndrome include:  

• Psychological support and counseling: this involves speaking with psychologists, sexologists, and/or experts in sexual disorders to enable patients to cope better with their psychological and psychosexual issues. 

Surgical treatments 

• Vaginoplasty: a surgical procedure where surgeons create a vagina by making a hole and securing the area around it using tissue from other parts of the body. 

Non-surgical treatments

• Vaginal Dilators: These are penis-resembling tube-like devices that are often made from plastic or silicone and function to stretch and dilate the vagina. They, therefore may help decrease the pain experienced by patients with MRKH syndrome during sexual intercourse.  

Fertility options 

• Adoption 

Recent research and future directions

Potential future treatment options

These mainly include:

• Gestational surrogacy (GS): due to the recent advancements in in-vitro fertilisation (IVF), adoption has no longer become the only option for patients with MRKH syndrome who desire to gain both legal and genetic motherhood. A more recent alternative to adoption is gestational surrogacy, which involves placing an embryo that is created via IVF using the biological mother’s eggs and father’s sperm into the womb of another woman. The woman or the ‘’gestational surrogate’’ or ‘’gestational carrier’’ therefore carries and delivers the baby for another person or family. 

It is worth noting that GS is banned in many countries across the world, including Nordic countries, due to ethical, religious, and/or legal reasons. 

• Uterine transplant: a surgical procedure that involves transplanting a donor uterus into a person without a uterus, thus enabling patients with MRKH syndrome to carry a successful pregnancy. 

Interestingly, the first MRKH syndrome-related world live birth using uterine transplant took place in Gothenburg, Sweden, in 2014.²

Summary 

• Often referred to as ‘’Müllerian aplasia’’, ‘’congenital absence of the uterus and vagina’’, and/or ‘’Müllerian agenesis’’, Mayer-Rokitansky-Küster-Hauser syndrome (MRKH syndrome) is a rare congenital disorder that mainly affects the reproductive system of around 1 in 5,000 women and people assigned female at birth (AFAB). It is named after the four scientists who thoroughly described it over a 130-year period. 
• The majority of women and people AFAB with MRKH syndrome are born with a missing or underdeveloped upper vagina, cervix and/or uterus (primary characteristics). However, some have normally functioning ovaries, fallopian tubes, and organs (Type 1) whilst others have abnormalities in their ovaries, fallopian tubes, kidneys, spine, ears, and/or heart (secondary characteristics) (Type 2). 
• MRKH syndrome makes menstruation, sexual intercourse, and pregnancy extremely difficult and even impossible. Sadly, as a result, many patients with MRKH syndrome experience great psychological distress and face struggles with their sexuality, identity, and self-esteem.  
• The exact cause of MRKH syndrome remains unknown to this day. Scientists do not understand why the Müllerian duct of women and people AFAB fails to form all the major female sex reproductive organs during fetal development. However, they believe genetic factors play a key role. 
• At present, MRKH syndrome is mainly diagnosed via physical examination, imaging tests (e.g. ultrasound and MRI), as well as genetic and/or hormonal testing.
• Management and treatment for MRKH syndrome include vaginoplasty, vaginal dilation, counselling, and/or adoption (current options), as well as uterine transplants and/or gestational surrogation (GS) (potential future options).