Active clinical trials for "Glycogen Storage Disease Type VII"

The aim of this study is to investigate the effect of 14 days of treatment with the dietary oil-supplement Triheptanoin on fat metabolism and exercise tolerance in patients with Phosphofructokinase deficiency, Debrancher deficiency and Glycogenin-1 deficiency. The investigators wish to investigate whether a Triheptanoin diet can improve exercise capacity by measuring: Heart rate during cycling exercise and maximal exercise capacity Fat and glucose metabolism Concentrations of metabolic substrates in blood during exercise Perception of fatigue and symptoms by questionnaire Degree of exhaustion during cycling exercise by Borg score All measurements are done before and after 14 days with a Triheptanoin-oil diet, and before and after 14 days diet with safflower (Placebo-oil). Triheptanoin-oil supplementation in the diet has been shown to increase metabolism of both fat and carbohydrates in patients with other metabolic myopathies. In these patients, Triheptanoin improved physical performance and has reduced the amount of symptoms experienced by patients.

Development of a new MS-based biomarker for the early and sensitive diagnosis of Glycogen Storage Diseases from plasma. Testing for clinical robustness, specificity and long-term stability of the biomarker.

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.

This study aims to characterize the pathophysiological mechanisms of 21 different metabolic myopathies. The study will focus on exercise capacity and the metabolic derangement during exercise.