Familial velopharyngeal incompetence caused by myasthenia gravis

This report describes 2 cases of familial myasthenia gravis presenting as velopharyngeal incompetence. The diagnosis was made only after pharyngoplasty had been done. Symptoms suggesting possible myasthenia gravis are seen in speech therapy and cleft palate clinics, and often labeled "palatal insufficiency" without a more specific diagnosis. In spite of the fact that myasthenia gravis is usually mentioned in the differential diagnosis of velopharyngeal incompetence, it is rarely ruled out by specific studies. We urge that myasthenia gravis be ruled out by definitive tests when the cause of neuromuscular dysfunction cannot be definitely established.