Oculopharyngeal muscular dystrophy
- Muscular dystrophy, oculopharyngeal
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Most cases of oculopharyngeal muscular dystrophy (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%.
- Oculopharyngeal muscular dystrophy. Genetics Home Reference (GHR). December 2008; http://ghr.nlm.nih.gov/condition=oculopharyngealmusculardystrophy. Accessed 12/8/2008.
- Bernard Brais, M Phil, and Guy A Rouleau. Oculopharyngeal Muscular Dystrophy. GeneReviews. June 22, 2006; http://www.ncbi.nlm.nih.gov/books/NBK1126/. Accessed 5/2/2012.