Phenotypes associated with the disease potassium-aggravated myotonia (OMIM:608390):
- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: PCS. Frequency: 1/2. (PMID:9771789)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:608390)
- Muscle stiffness (HP:0003552): A condition in which muscles cannot be moved quickly without accompanying pain or spasm. Evidence: IEA. (OMIM:608390)
- Stridor (HP:0010307): Stridor is a high pitched sound resulting from turbulent air flow in the upper airway. Evidence: IEA. (OMIM:608390)
- Myotonia (HP:0002486): An involuntary and painless delay in the relaxation of skeletal muscle following contraction or electrical stimulation. Evidence: PCS. Frequency: 2/2. (PMID:9771789)
- Handgrip myotonia (HP:0012899): Difficulty releasing one's grip associated with prolonged first handgrip relaxation times. Evidence: PCS. Frequency: 1/2. (PMID:9771789)
- Percussion myotonia (HP:0010548): A localized myotonic contraction in a muscle in reaction to percussion (tapping with the examiner's finger, a rubber percussion hammer, or a similar object). Evidence: PCS. Frequency: 2/2. (PMID:9771789)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 1/2. (PMID:9771789)
- Apneic episodes in infancy (HP:0005949): Recurrent episodes of apnea occurring during infancy. Evidence: TAS. (OMIM:608390)
- Laryngospasm (HP:0025425): A spasm (involuntary contraction) of the vocal cords that can make it difficult to speak or breathe. Evidence: TAS. Onset: Neonatal onset (HP:0003623). (OMIM:608390)
- Skeletal muscle hypertrophy (HP:0003712): Abnormal increase in muscle size and mass not due to training. Evidence: IEA. (OMIM:608390)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 0/2. (PMID:9771789)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:9771789)
- Myalgia (HP:0003326): Pain in muscle. Evidence: IEA. (OMIM:608390)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 1/2. (PMID:9771789)