Question: What is (are) Glycogen storage disease type 7 ?
Answer: Glycogen storage disease type 7 (GSD7) is an inherited condition in which the body is unable to break down glycogen (a complex sugar) in the muscle cells. Because glycogen is an important source of energy, this can interfere with the normal functioning of muscle cells. The severity of the condition and the associated signs and symptoms vary, but may include muscle weakness and stiffness; painful muscle cramps; nausea and vomiting; and/or myoglobinuria (the presence of myoglobin in the urine) following moderate to strenuous exercise. Symptoms typically resolve with rest. GSD7 is most commonly diagnosed during childhood; however, some affected people may rarely develop symptoms during infancy or later in adulthood. Those who develop the condition during infancy may experience additional symptoms such as hypotonia (poor muscle tone), cardiomyopathy and breathing difficulties that often lead to a shortened lifespan (less than 1 year). This condition is caused by changes (mutations) in the PFKM gene and is inherited in an autosomal recessive manner. There is no specific treatment for GSD7; however, affected people are generally advised to avoid vigorous exercise and high-carbohydrate meals.
Source: GARD

Question: What are the symptoms of Glycogen storage disease type 7 ?
Answer: What are the signs and symptoms of Glycogen storage disease type 7? The Human Phenotype Ontology provides the following list of signs and symptoms for Glycogen storage disease type 7. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Myotonia 90% Skeletal muscle atrophy 50% Autosomal recessive inheritance - Cholelithiasis - Exercise intolerance - Exercise-induced muscle cramps - Exercise-induced myoglobinuria - Gout - Hemolytic anemia - Increased muscle glycogen content - Increased total bilirubin - Jaundice - Muscle weakness - Reduced erythrocyte 2,3-diphosphoglycerate concentration - Reticulocytosis - Variable expressivity - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD