How do people inherit oculopharyngeal muscular dystrophy?
Most cases of oculopharyngeal muscular dystrophy are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. People with autosomal dominant oculopharyngeal muscular dystrophy have a mutation resulting in a PABPN1 protein with an expanded polyalanine tract of between 12 and 17 alanines. Less commonly, oculopharyngeal muscular dystrophy can be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. In autosomal recessive oculopharyngeal muscular dystrophy, PABPN1 mutations lead to a polyalanine tract that is 11 alanines long. 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.
