Phenotypes associated with the disease glycogen storage disease due to muscle and heart glycogen synthase deficiency (OMIM:611556):
- Bilateral tonic-clonic seizure (HP:0002069): A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Type 2 muscle fiber atrophy (HP:0003554): Atrophy (wasting) affecting primary type 2 muscle fibers. This feature in general can only be observed on muscle biopsy. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Decreased myocardial glycogen content (HP:6001440): The amount of glycogen in the myocardial tissue of the heart is below the lower limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Stroke (HP:0001297): Sudden impairment of blood flow to a part of the brain due to occlusion or rupture of an artery to the brain. Evidence: IEA. (OMIM:611556)
- Cardiac arrest (HP:0001695): An abrupt loss of heart function. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Fatty replacement of skeletal muscle (HP:0012548): Muscle fibers degeneration resulting in fatty replacement of skeletal muscle fibers. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Reduced hepatic glycogen phosphorylase activity (HP:6000979): Activity or concentration of glycogen phosphorylase L in the liver below the lower limit of normal. Evidence: PCS. Frequency: 0/1. (PMID:17928598)
- Limited ankle dorsiflexion (HP:0033526): Reduced ability to move the foot up toward the shin. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 3/4. (PMID:21958591;PMID:17928598)
- Left atrial enlargement (HP:0031295): Increase in size of the left atrium. Evidence: PCS. Frequency: 2/2. (PMID:17928598)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Limb pain (HP:0009763): Chronic pain in the limbs with no clear focal etiology. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Decreased muscle glycogen content (HP:0012270): A decreased amount of glycogen in muscle tissue. Evidence: PCS. Frequency: 3/3. (PMID:21958591;PMID:17928598)
- Type 1 muscle fiber predominance (HP:0003803): An abnormal predominance of type I muscle fibers (in general, this feature can only be observed on muscle biopsy). Evidence: PCS. Frequency: 2/2. (PMID:17928598)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 1/2. (PMID:17928598)
- Proximal muscle weakness (HP:0003701): A lack of strength of the proximal muscles. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Exercise intolerance (HP:0003546): A functional motor deficit where individuals whose responses to the challenges of exercise fail to achieve levels considered normal for their age and gender. Evidence: PCS. Frequency: 2/2. (PMID:17928598)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 1/3. (PMID:17928598)
- Cardiomyocyte hypertrophy (HP:0031319): An increase in cell size, enhanced protein synthesis, and heightened organization of the sarcomere within cardiac myocytes. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Interictal EEG abnormality (HP:0025373): Interictal refers to a period of time between epileptic seizures. Electroencephalographic (EEG) patterns are important in the differential diagnosis of epilepsy, and the EEG is almost always abnormal during a seizure. Some persons with seizures may show EEG abnormalities between seizures, while others do not. In some cases, multiple interictal EEGs must be recorded before an abnormality is observed. In most cases the electrographic pattern of seizure onset is completely different from the activity recorded during interictal discharge. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Ventricular septal hypertrophy (HP:0005144): The dividing wall between left and right sides of the heart, thickens and bulges into the left ventricle. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Bilateral tonic-clonic seizure with generalized onset (HP:0025190): A bilateral tonic-clonic seizure with generalized onset is a type of bilateral tonic-clonic seizure characterized by generalized onset; these seizures rapidly engage networks in both hemispheres at the start of the seizure. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Myocardial sarcomeric disarray (HP:0031333): A disruption of the structure of the sarcomeres of cardiomyocytes. The sarcomere is the repeating unit between two Z lines comprised largely of myosin and actin that mediates contractility, and normally sarcomeres are aligned with the long axis of cells, with the Z bands being in register throughout the length of the cardiac myocytes. Evidence: PCS. Frequency: 0/1. (PMID:17928598)
- Prolonged QTc interval (HP:0005184): A longer than normal interval (corrected for heart rate) between the Q and T waves in the heart's cycle. Prolonged QTc can cause premature action potentials during late phase depolarizations thereby leading to ventricular arrhythmias and ventricular fibrillations. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Fatigue (HP:0012378): A subjective feeling of tiredness characterized by a lack of energy and motivation. Evidence: PCS. Frequency: 1/1. (PMID:17928598)
- Failure to elevate lactate upon ischemic exercise test (HP:6000526): Failure to elevate lactate in blood washed out from ischemically exercised muscles as assayed by the forearm ischemic exercise test. Evidence: PCS. Frequency: 2/2. (PMID:21958591;PMID:17928598)
- Hypertrophic cardiomyopathy (HP:0001639): Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality. Evidence: PCS. Frequency: 0/1. (PMID:17928598)
- Exercise-induced myalgia (HP:0003738): The occurrence of an unusually high amount of muscle pain following exercise. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:17928598)
- Left ventricular hypertrophy (HP:0001712): Enlargement or increased size of the heart left ventricle. Evidence: TAS. (OMIM:611556)
- Cardiomyopathy (HP:0001638): A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Evidence: PCS. (PMID:17928598)
- Syncope (HP:0001279): A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Asthenia (HP:0025406): A state characterized by a feeling of weakness and loss of strength leading to a generalized weakness of the body. Evidence: PCS. Frequency: 1/1. (PMID:21958591)
- Sudden death (HP:0001699): Rapid and unexpected death. Evidence: PCS. Frequency: 1/1. (PMID:21958591)