Müllerian aplasia and hyperandrogenism

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Müllerian aplasia and hyperandrogenism is a condition that affects the reproductive system in females. This condition is caused by abnormal development of the Müllerian ducts, which are structures in the embryo that develop into the uterus, fallopian tubes, cervix, and the upper part of the vagina. Individuals with Müllerian aplasia and hyperandrogenism typically have an underdeveloped or absent uterus and may also have abnormalities of other reproductive organs. Women with this condition have normal female external genitalia, and they develop breasts and pubic hair normally at puberty; however, they do not begin menstruation by age 16 (primary amenorrhea) and will likely never have a menstrual period. Affected women are unable to have children (infertile).

Women with Müllerian aplasia and hyperandrogenism have higher-than-normal levels of male sex hormones called androgens in their blood (hyperandrogenism), which can cause acne and excessive facial hair (facial hirsutism). Kidney abnormalities may be present in some affected individuals.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the WNT4 gene cause Müllerian aplasia and hyperandrogenism. This gene belongs to a family of WNT genes that play critical roles in development before birth. The WNT4 gene provides instructions for producing a protein that is important for the formation of the female reproductive system, the kidneys, and several hormone-producing glands. During the development of the female reproductive system, the WNT4 protein regulates the formation of the Müllerian ducts. This protein is also involved in development of the ovaries, from before birth through adulthood, and is important for development and maintenance of egg cells (oocytes) in the ovaries. In addition, the WNT4 protein regulates the production of androgens.

Mutations in the WNT4 gene change single protein building blocks (amino acids) in the WNT4 protein. Researchers suspect that the altered protein cannot be released from cells as it normally would be; the trapped protein is unable to perform its usual functions. Loss of regulation by WNT4 likely disrupts development of the female reproductive system and induces abnormal production of androgens, leading to the features of Müllerian aplasia and hyperandrogenism.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Girls with Müllerian aplasia and hyperandrogenism do not inherit the mutation from their mother, because women with this disorder cannot have children. It is unknown, though, if an affected person inherits the mutation from her father or if the condition is caused by new mutations in the gene. Müllerian aplasia and hyperandrogenism may occur in people with no history of the disorder in their family.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Müllerian aplasia and hyperandrogenism is a very rare disorder; it has been identified in only a few individuals worldwide.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormality of the vagina · Very frequent (99-80%)

Any structural abnormality of the vagina.

Acne · Very frequent (99-80%)

A skin condition in which there is an increase in sebum secretion by the pilosebaceous apparatus associated with open comedones (blackheads), closed comedones (whiteheads), and pustular nodules (papules, pustules, and cysts).

Facial hirsutism · Very frequent (99-80%)

Excess facial hair.

Frontal balding · Very frequent (99-80%)

Absence of hair in the anterior midline and/or parietal areas.

High anterior hairline · Very frequent (99-80%)

Distance between the hairline (trichion) and the glabella (the most prominent point on the frontal bone above the root of the nose), in the midline, more than two SD above the mean. Alternatively, an apparently increased distance between the hairline and the glabella.

Hirsutism · Very frequent (99-80%)

Abnormally increased hair growth referring to a male pattern of body hair (androgenic hair).

Hypoplasia of the uterus · Very frequent (99-80%)

Underdevelopment of the uterus.

Increased serum testosterone level · Very frequent (99-80%)

An elevated circulating testosterone level in the blood.

Short stature · Very frequent (99-80%)

A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).

Primary amenorrhea · Very frequent (99-80%)

Obesity · Frequent (79-30%)

Accumulation of substantial excess body fat.

Abnormality of the ovary · Occasional (29-5%)

An abnormality of the ovary.

Brachydactyly · Occasional (29-5%)

Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here.

Cleft palate · Occasional (29-5%)

Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate).

Other findings in the same source

From: Orphanet

Additional reported features include Cubitus valgus (Occasional (29-5%)); Protruding ear (Occasional (29-5%)); Renal agenesis (Occasional (29-5%)); Shield chest (Occasional (29-5%)); Short neck (Occasional (29-5%)); Short philtrum (Occasional (29-5%)); Synophrys (Occasional (29-5%)); Thick eyebrow (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Müllerian aplasia and hyperandrogenism is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Müllerian aplasia and hyperandrogenism. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.