Oculopharyngeal muscular dystrophy

What causes oculopharyngeal muscular dystrophy (OPMD)?

OPMD is caused by mutations in the PABPN1 gene. The PABPN1 gene provides instructions for making the PABPN1 protein that is active (expressed) throughout the body. In cells, the PABPN1 protein plays an important role in processing molecules called messenger RNAs (mRNAs), which serve as genetic blueprints for making proteins. The protein acts to protect the mRNA from being broken down and allows it to move within the cell.

The PABPN1 gene contains a section of DNA called a GCN repeat, which normally repeats around 10 times. In cases of OPMD, this section of DNA is repeated 11-17 times. This results in the protein having too many of an amino acid called alanine. The extra alanine causes the PABPN1 protein to form clumps within muscle cells that cannot be broken down. These clumps are thought to impair the normal function of muscle cells and eventually cause cells to die. The progressive loss of muscle cells most likely causes the muscle weakness seen in people with OPMD. It is not known why abnormal PABPN1 proteins seem to affect muscle cells in only certain parts of the body.

Last updated on 05-01-20

Is genetic testing available for oculopharyngeal muscular dystrophy?

Genetic testing is available for oculopharyngeal muscular dystrophy (OPMD). GeneTests lists the names of laboratories that are performing genetic testing for this condition. To view the contact information for the clinical laboratories conducting testing click here. Please note that most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, individuals that are interested in learning more will need to work with a health care provider or a genetics professional.

Last updated on 05-01-20

Should individuals with a relative affected with oculopharyngeal muscular dystrophy be tested for the condition?

Oculopharyngeal muscular dystrophy (OPMD) is inherited in either an autosomal dominant or an autosomal recessive manner. More detailed information about the inheritance of OPMD can be viewed on our Web site by clicking here.

An individual who may be at risk for having inherited a mutation for OPMD may benefit from learning the type of OPMD that is present in the family, if possible. Furthermore, there are various considerations when contemplating having genetic testing for an adult- or late-onset condition (known as predictive testing). More information about predictive testing, including points to consider, can be viewed by clicking here. Genetic counseling is recommended for asymptomatic individuals seeking information about predictive testing for this condition.

Last updated on 05-01-20

How is oculopharyngeal muscular dystrophy (OPMD) inherited?

Most cases of OPMD are inherited in an autosomal dominant manner, which means one copy of the altered (mutated) gene in each cell is sufficient to cause the condition. Individuals have two copies of each gene; one copy having been inherited from each parent. An individual with the autosomal dominant form of OPMD may have inherited the condition from an affected parent, or less commonly, the condition may occur for the first time in the affected individual. Each child of an affected individual with this form of OPMD has a 50% (1 in 2) chance to be affected and a 50% chance to be unaffected.

Less commonly, OPMD is inherited in an autosomal recessive manner, which means that both copies of the disease-causing gene in each cell must have a mutation for an individual to be affected. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene (and are referred to as carriers), but they typically do not show signs and symptoms of the condition. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) chance to be affected, a 50% (1 in 2) chance to be a carrier like each of the parents, and a 25% chance to be unaffected and not be a carrier. The children of an individual with autosomal recessive OPMD will always be carriers (obligate heterozygotes) for the disease-causing mutation. The risk of a child being affected if his/her parent has autosomal recessive OPMD is less than 1%.

Last updated on 05-01-20

In which populations does oculopharyngeal muscular dystrophy occur?

Oculopharyngeal muscular dystrophy (OPMD) affects males and females in equal numbers. The condition has been reported in over 30 countries. The prevalence of autosomal dominant OPMD has been estimated to be 1 in 100,000 in France, 1 in 1000 in the French-Canadian population of the province of Quebec, and 1 in 600 among Bukhara Jews living in Israel. In the United States, the majority of affected individuals are of French-Canadian descent, although a large number are also of other backgrounds including Jewish Ashkenazi and Spanish American in Texas and California. The predicted prevalence of the autosomal recessive form is estimated to be about 1 in 10,000 in France, Quebec, and Japan.

Last updated on 05-01-20

Could being affected by oculopharyngeal muscular dystrophy (OPMD) affect sperm mobility?

After an extensive search of the resources available to us, we have not been able to identify any indication that sperm mobility is affected in individuals with OPMD. Likewise, there are no reports of problems with fertility in individuals as a result of this condition. If you have additional questions or concerns regarding this issue, we strongly recommend that you discuss them with your healthcare provider.

Last updated on 05-01-20

Where can I find information about participating in a clinical trial?

The National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. If you are interested, click on the above and type "oculopharyngeal muscular dystrophy" into the search box.

You can also contact the Patient Recruitment and Public Liaison (PRPL) Office at the National Institutes of Health (NIH). We recommend calling the toll-free number listed below to speak with a specialist, who can help you determine if you are eligible for any other clinical trials.

Patient Recruitment and Public Liaison Office (PRPL)
NIH Clinical Center
Bethesda, Maryland 20892-2655
Toll-free: 800-411-1222
Fax: 301-480-9793
Email: prpl@mail.cc.nih.gov
Web site: http://clinicalcenter.nih.gov/

If you are interested in enrolling in a clinical trial, you can find helpful information on our get involved in research page.

Last updated on 05-01-20

How might oculopharyngeal muscular dystrophy impact my life?

It is not possible to predict exactly how oculopharyngeal muscular dystrophy will impact one's life. Although the common signs and symptoms have been well studied, the age in which symptoms appear and the severity varies.

Typically the life expectancy of people with this condition is not reduced. Some people with oculopharyngeal muscular dystrophy may need a cane or a walker as the disease worsens over time. Rarely, an individual may need a wheelchair due to severe lower body muscle weakness.

Last updated on 05-01-20

What is oculopharyngeal muscular dystrophy?

Oculopharyngeal muscular dystrophy (OPMD) is a genetic disorder characterized by slowly progressing muscle disease (myopathy) affecting the muscles of the upper eyelids and the throat. Onset is typically during adulthood, most often between 40 and 60 years of age. Symptoms may include: eyelid drooping (ptosis), arm and leg weakness, and difficulty swallowing (dysphagia). There are two types of OPMD, distinguished by their patterns of inheritance. They are known as the autosomal dominant and autosomal recessive types. Both types are caused by mutations in the PABPN1 gene.Treatment depends on the signs and symptoms present in each individual. Ptosis and dysphagia can be managed with surgery; however, recurrence of symptoms commonly occurs 5-15 years after intervention.

Last updated on 05-01-20

Can the symptoms of oculopharyngeal muscular dystrophy (OPMD) occur at earlier ages in subsequent generations (known as anticipation)?

Families with OPMD showing earlier onset of symptoms in subsequent generations have not been reported in the medical literature. The GCN repeat in the PABPN1 gene is stable when passed down or inherited. Therefore, expansion of the triplet repeat when inherited from the egg or sperm is rare.

Severe cases of OPMD with earlier symptom onset represent 5% to 10% of all cases. These individuals have onset of ptosis and dysphagia before 45 years and an incapacitating proximal leg weakness that starts before age 60 years.

Last updated on 05-01-20

What are the risks that a future child could inherit oculopharyngeal muscular dystrophy (OPMD)?

Any risk to your future offspring depends on your husband's health status. Testing of at-risk asymptomatic adults for OPMD is available. This testing is not useful in predicting age of onset, severity, type of symptoms, or rate of progression in asymptomatic individuals. When testing at-risk individuals for oculopharyngeal muscular dystrophy, an affected family member should be tested first to confirm that the disorder in the family is actually oculopharyngeal muscular dystrophy.

Genetic counseling may help you both better understand the above-mentioned testing, your husband's health status, and the risk of passing this disease on to the next generation.

Last updated on 05-01-20

How rare is oculopharyngeal muscular dystrophy?

The autosomal dominant form of oculopharyngeal muscular dystrophy (OPMD) is most common among a population of Bukharan Jews living in Israel, where an estimated 1 person in 600 is affected. OPMD is additionally estimated to occur in 1 in 1000 individuals of French-Canadian ancestry and 1 in 100,000 individuals in France. In the United States, the number of people with OPMD is not known, however the majority of diagnosed individuals are of French-Canadian, Ashkenazi Jewish, or Spanish American background.

The autosomal recessive form of OPMD is estimated to occur in 1 in 10,000 individuals in France, Quebec, and Japan. This estimate is based the number of individuals found to be carriers in these populations (carrier frequency).

Last updated on 05-01-20

How might oculopharyngeal muscular dystrophy be treated?

Treatment of oculopharyngeal muscular dystrophy (OPMD) mainly focuses on the specific signs and symptoms present in each individual. Severe drooping of the eyelid (ptosis) may be treated with plastic surgery on the eyelid (blepharoplasty). The goal of this surgery is to raise the eyelid so that the affected individual can see. Individuals with severe difficulty swallowing (dysphagia) may have a surgical procedure known as cricopharyngeal myotomy. In this procedure, the cricopharyngeal muscle of the throat is cut so that when swallowing occurs, the muscle remains relaxed allowing the passage of food or liquid. Orthopedic devices such as canes, leg braces, or walkers can assist individuals who have difficulty walking. Other treatment is symptomatic and supportive.

Last updated on 05-01-20

Where To Start

MDA - oculopharyngeal muscular dystrophy

The Muscular Dystrophy Association (MDA) provides additional information about oculopharyngeal muscular dystrophy in their publication entitled, Oculopharyngeal Muscular Dystrophy (OPMD)

Last updated on 04-27-20

Name: European Alliance of Neuromuscular Disorders Associations MDG Malta 4 Gzira Road
Gzira, Intl GAR 04
Malta
Phone: 003-56 -21 346688 Email: eamda@hotmail.com Url: http://www.eamda.eu/
Name: Muscular Dystrophy Association MDA 222 S Riverside Plaza Suite 1500
Chicago, IL, 60606, United States
Toll Free: 1-833-275-6321 (Helpline) Email: resourcecenter@mdausa.org Url: https://www.mda.org
Name: Muscular Dystrophy UK 61A Great Suffolk Street
London, SE1 0BU, United Kingdom
Phone: (+44) 0 020 7803 4800 Toll Free: 0800 652 6352 (Helpline) Email: info@musculardystrophyuk.org Url: https://www.musculardystrophyuk.org/

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