Phenotypes associated with the disease Autosomal dominant mitochondrial myopathy with exercise intolerance (ORPHA:457050):
- Restrictive ventilatory defect (HP:0002091): A functional defect characterized by reduced total lung capacity (TLC) not associated with abnormalities of expiratory airflow or airway resistance. Spirometrically, a restrictive defect is defined as FEV1 (forced expiratory volume in 1 second) and FVC (forced vital capacity) less than 80 per cent. Restrictive lung disease may be caused by alterations in lung parenchyma or because of a disease of the pleura, chest wall, or neuromuscular apparatus. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Increased circulating lactate concentration (HP:0002151): Abnormally increased level of blood lactate (2-hydroxypropanoic acid). Lactate is produced from pyruvate by lactate dehydrogenase during normal metabolism. The terms lactate and lactic acid are often used interchangeably but lactate (the component measured in blood) is strictly a weak base whereas lactic acid is the corresponding acid. Lactic acidosis is often used clinically to describe elevated lactate but should be reserved for cases where there is a corresponding acidosis (pH below 7.35). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Ragged-red muscle fibers (HP:0003200): An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Neck flexor weakness (HP:0003722): Weakness of the muscles involved in neck flexion (sternocleidomastoid, longus capitus, longus colli, and scalenus anterior). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Mildly elevated creatine kinase (HP:0008180). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Proximal lower limb muscle weakness (HP:0008994): A lack of strength of the proximal muscles of the legs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Distal lower limb muscle weakness (HP:0009053): Reduced strength of the distal musculature of the legs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Increased intramyocellular lipid droplets (HP:0012240): An abnormal increase in intracellular lipid droplets In a muscle. The number and size of these drops can increase with somd disorders of lipid metabolism affecting muscle. See PMID 20691590 for histological images. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Weakness of facial musculature (HP:0030319): Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Increased mitochondrial number (HP:0040014). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457050)
- Proximal upper limb muscle weakness (HP:0008997): A lack of strength of the proximal muscles of the arms. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457050)