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.

Individuals with OPMD may also have double vision (diplopia) and frequently have weakness in the muscles near the center of the body (proximal muscles), particularly muscles in the upper legs and hips. The weakness progresses slowly over time, and people may need the aid of a cane or a walker. Rarely, affected individuals need wheelchair assistance.

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.

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%.

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.

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.