Genetic and Family Studies of Inherited Muscle Diseases

Study Summary

The purposes of this study are to identify gene mutations in patients with the muscle diseases phosphofructokinase (PFK) deficiency, acid maltase deficiency (GAA deficiency) and to learn more about how these diseases develop. PFK deficiency is a mild, exercise-related illness. The childhood form of GAA deficiency (Pompe disease) affects the heart and liver and is rapidly fatal. The adult form begins in midlife and involves degeneration of skeletal muscles, leading to weakness and muscle wasting. The following groups of individuals may be eligible for this study: Group A: Patients with PFK deficiency, acid maltase deficiency, and relatives who also are affected. Participants in this group will undergo a brief medical and family history, blood sample collection, and possibly a physical examination, review of medical records, and interview with the patient's physician. Group B: Unaffected family members of patients in group A, including both blood relatives and spouses. People in this group may be asked to provide a history and genetic information. A review of medical records, interview with the individual's physician, and blood sample may also be requested. Group C: Control subjects. This group will provide a small blood sample or buccal mucosal sample (tissue sample collected by brushing the inside of the cheek). The samples will be coded and the investigators will not know the participants' identities. DNA from these samples will be analyzed for frequency of gene mutations. Genetic counseling will be arranged for patients, as appropriate.