- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: PCS. Frequency: 13/14. (PMID:30918256)
- 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: 12/14. (PMID:30918256)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 10/14. (PMID:30918256)
- 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: 14/14. (PMID:30918256)
- Adult onset (HP:0003581): Onset of disease manifestations in adulthood, defined here as at the age of 16 years or later. Evidence: PCS. Frequency: 14/14. (PMID:30918256)
- Sarcoplasmic bodies (HP:0034722): Rounded or oval structures that appeared brown on hematoxylin and eosin and red on the modified Gomori trichrome stain. Evidence: PCS. Frequency: 21/24. (PMID:30918256;PMID:35527200;PMID:16146490)
- Weakness of facial musculature (HP:0030319): Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve). Evidence: PCS. Frequency: 0/14. (PMID:30918256)
- Proximal lower limb muscle weakness (HP:0008994): A lack of strength of the proximal muscles of the legs. Evidence: PCS. Frequency: 14/14. (PMID:30918256)
- Weakness of the intrinsic hand muscles (HP:0009005). Evidence: PCS. Frequency: 13/14. (PMID:30918256)
- 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: 8/14. (PMID:30918256)
- Respiratory insufficiency due to muscle weakness (HP:0002747). Evidence: PCS. Frequency: 9/14. (PMID:30918256)
- Axial muscle weakness (HP:0003327): Reduced strength of the axial musculature (i.e., of the muscles of the head and neck, spine, and ribs). Evidence: PCS. Frequency: 13/14. (PMID:30918256)
- 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:30918256)
- 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: 11/14. (PMID:30918256)
These phenotypes are associated with the disease myopathy, sarcoplasmic body (OMIM:620286).