- 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: 1/1. (PMID:31852522)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 2/10. (PMID:33217308)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 3/10. (PMID:33217308)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/10. (PMID:33217308)
- Coarctation of aorta (HP:0001680): Coarctation of the aorta is a narrowing or constriction of a segment of the aorta. Evidence: PCS. Frequency: 2/10. (PMID:33217308)
- Gowers sign (HP:0003391): A phenomenon whereby patients are not able to stand up without the use of the hands owing to weakness of the proximal muscles of the lower limbs. Evidence: PCS. Frequency: 1/1. (PMID:31852522)
- Fatigue (HP:0012378): A subjective feeling of tiredness characterized by a lack of energy and motivation. Evidence: PCS. Frequency: 2/10. (PMID:33217308)
- Muscle fiber granulofilamentous inclusion bodies (HP:0034635): The presence of inclusion bodies within the cytoplasm of muscle cells that contain a mxiture of granules and filaments. Evidence: PCS. Frequency: 2/8. (PMID:33217308)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: IEA. Frequency: 7/10. (PMID:33217308)
- Reduced forced vital capacity (HP:0032341): An abnormal reduction in the amount of air a person can expel following maximal inspiration. Evidence: PCS. Frequency: 1/1. (PMID:31852522)
- Calf muscle hypertrophy (HP:0008981): Muscle hypertrophy affecting the calf muscles. Evidence: PCS. Frequency: 5/10. (PMID:33217308)
- Decreased fetal movement (HP:0001558): An abnormal reduction in quantity or strength of fetal movements. Evidence: PCS. Frequency: 1/1. Onset: Antenatal onset (HP:0030674). (PMID:31852522)
- Feeding difficulties in infancy (HP:0008872): Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention. Evidence: PCS. Frequency: 1/1. Onset: Infantile onset (HP:0003593). (PMID:31852522)
- Overweight (HP:0025502): Increased body weight with a body mass index of 25-29.9 kg per square meter. Evidence: PCS. Frequency: 1/1. (PMID:31852522)
- 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: 6/8. (PMID:33217308)
- Proximal muscle weakness (HP:0003701): A lack of strength of the proximal muscles. Evidence: PCS. Frequency: 9/10. (PMID:33217308)
- 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: 3/10. (PMID:33217308)
- Z-band streaming (HP:0020203): Streaming or smearing of the Z band, which is then no longer confined to a narrow zone which bisects the I band. The Z disk may extend across the I band or the entire sarcomere in a zigzag manner. Focal thickening, smudging, and blurring of the Z band takes place concurrently. Myofibrillar disorganization is a frequent but not invariable accompanying change. Evidence: PCS. Frequency: 1/1. (PMID:31852522)
- Shoulder girdle muscle atrophy (HP:0003724): Amyotrophy affecting the muscles of the shoulder girdle. Evidence: PCS. Frequency: 1/10. (PMID:33217308)
- 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:31852522)
- Hypernasal speech (HP:0001611): A type of speech characterized by the presence of an abnormally increased nasal airflow during speech associated with structural abnormality of the nasal passages. Evidence: PCS. Frequency: 1/1. (PMID:31852522)
- 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: 5/9. (PMID:33217308;PMID:31852522)
- Generalized amyotrophy (HP:0003700): Generalized (diffuse, unlocalized) amyotrophy (muscle atrophy) affecting multiple muscles. Evidence: PCS. Frequency: 1/10. (PMID:33217308)
- EMG: myopathic abnormalities (HP:0003458): The presence of abnormal electromyographic patterns indicative of myopathy, such as small-short polyphasic motor unit potentials. Evidence: PCS. Frequency: 5/10. (PMID:33217308)
These phenotypes are associated with the disease myofibrillar myopathy 11 (OMIM:619178).