Manitoba oculotrichoanal syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Manitoba oculotrichoanal syndrome is a condition involving several characteristic physical features, particularly affecting the eyes (oculo-), hair (tricho-), and anus (-anal).

People with Manitoba oculotrichoanal syndrome have widely spaced eyes (hypertelorism). They may also have other eye abnormalities including small eyes (microphthalmia), a notched or partially absent upper eyelid (upper eyelid coloboma), eyelids that are attached to the front surface of the eye (corneopalpebral synechiae), or eyes that are completely covered by skin and usually malformed (cryptophthalmos). These abnormalities may affect one or both eyes.

Individuals with Manitoba oculotrichoanal syndrome usually have abnormalities of the front hairline, such as hair growth extending from the temple to the eye on one or both sides of the face. One or both eyebrows may be completely or partially missing. Most people with this disorder also have a wide nose with a notched tip; in some cases this notch extends up from the tip so that the nose appears to be divided into two halves (bifid nose).

About 20 percent of people with Manitoba oculotrichoanal syndrome have defects in the abdominal wall, such as a soft out-pouching around the belly-button (an umbilical hernia) or an opening in the wall of the abdomen (an omphalocele) that allows the abdominal organs to protrude through the navel. Another characteristic feature of Manitoba oculotrichoanal syndrome is a narrow anus (anal stenosis) or an anal opening farther forward than usual. Umbilical wall defects or anal malformations may require surgical correction. Some affected individuals also have malformations of the kidneys.

The severity of the features of Manitoba oculotrichoanal syndrome may vary even within the same family. With appropriate treatment, affected individuals generally have normal growth and development, intelligence, and life expectancy.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Manitoba oculotrichoanal syndrome is caused by mutations in the FREM1 gene.

The FREM1 gene provides instructions for making a protein that is involved in the formation and organization of basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues.

The FREM1 protein is one of a group of proteins, including proteins called FRAS1 and FREM2, that interact during embryonic development as components of basement membranes. Basement membranes help anchor layers of cells lining the surfaces and cavities of the body (epithelial cells) to other embryonic tissues, including those that give rise to connective tissues such as skin and cartilage.

The FREM1 gene mutations that have been identified in people with Manitoba oculotrichoanal syndrome delete genetic material from the FREM1 gene or result in a premature stop signal that leads to an abnormally short FREM1 protein. These mutations most likely result in a nonfunctional protein.

Absence of functional FREM1 protein interferes with its role in embryonic basement membrane development and may also affect the location, stability, or function of the FRAS1 and FREM2 proteins. The features of Manitoba oculotrichoanal syndrome may result from the failure of neighboring embryonic tissues to fuse properly due to impairment of the basement membranes' anchoring function.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Manitoba oculotrichoanal syndrome is estimated to occur in 2 to 6 in 1,000 people in a small isolated Ojibway-Cree community in northern Manitoba, Canada. Although this region has the highest incidence of the condition, it has also been diagnosed in a few people from other parts of the world.

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.

Abnormal hair pattern · Very frequent (99-80%)

An abnormality of the distribution of hair growth.

Hypertelorism · Very frequent (99-80%)

Interpupillary distance more than 2 SD above the mean (alternatively, the appearance of an increased interpupillary distance or widely spaced eyes).

Upper eyelid coloboma · Very frequent (99-80%)

A short discontinuity of the margin of the upper eyelid.

Anal stenosis · Frequent (79-30%)

Abnormal narrowing of the anal opening.

Anteriorly placed anus · Frequent (79-30%)

Anterior malposition of the anus.

Nasolacrimal duct obstruction · Frequent (79-30%)

Blockage of the lacrimal duct.

Anophthalmia · Occasional (29-5%)

Absence of the globe or eyeball.

Bifid nasal tip · Occasional (29-5%)

A splitting of the nasal tip. Visually assessable vertical indentation, cleft, or depression of the nasal tip.

Other findings in the same source

From: Orphanet

Additional reported features include Cryptophthalmos (Occasional (29-5%)); Microphthalmia (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 Manitoba oculotrichoanal syndrome 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

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

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.