- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 3/6. (PMID:34957489)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 6/6. (PMID:34957489)
- Centrally nucleated skeletal muscle fibers (HP:0003687): An abnormality in which the nuclei of sarcomeres take on an abnormally central localization (or in which this feature is found in an increased proportion of muscle cells). Evidence: PCS. Frequency: 1/5. (PMID:34957489)
- Rhabdomyolysis (HP:0003201): Breakdown of muscle fibers that leads to the release of muscle fiber contents (myoglobin) into the bloodstream. Evidence: PCS. Frequency: 6/6. (PMID:34957489)
- Renal insufficiency (HP:0000083): A reduction in the level of performance of the kidneys in areas of function comprising the concentration of urine, removal of wastes, the maintenance of electrolyte balance, homeostasis of blood pressure, and calcium metabolism. Evidence: PCS. Frequency: 2/6. (PMID:34957489)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: PCS. Frequency: 1/6. (PMID:34957489)
- Type 2 muscle fiber predominance (HP:0010602): An abnormal predominance of type II muscle fibers (in general, this feature can only be observed on muscle biopsy). Evidence: PCS. Frequency: 1/5. (PMID:34957489)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 3/6. (PMID:34957489)
- 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:34957489)
- Abnormal circulating acylcarnitine concentration (HP:0012071): Any deviation from the normal concentration in the blood circulation of an acylcarnitine, which is produced by reversible esterification of the 3-hydroxyl group of carnitine. Evidence: PCS. Frequency: 0/6. (PMID:34957489)
- Increased variability in muscle fiber diameter (HP:0003557): An abnormally high degree of muscle fiber size variation. This phenotypic feature can be observed upon muscle biopsy. Evidence: PCS. Frequency: 3/5. (PMID:34957489)
- 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: 3/6. (PMID:34957489)
- Myalgia (HP:0003326): Pain in muscle. Evidence: PCS. Frequency: 5/6. (PMID:34957489)
These phenotypes are associated with the disease rhabdomyolysis, susceptibility to, 1 (OMIM:620235).