- Progressive muscle weakness (HP:0003323). Evidence: TAS. (OMIM:609452)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: IEA. (OMIM:609452)
- EMG: neuropathic changes (HP:0003445): The presence of characteristic findings of denervation on electromyography (fibrillations, positive sharp waves, and giant motor unit potentials). Evidence: IEA. (OMIM:609452)
- Muscle fiber splitting (HP:0003555): Fiber splitting or branching is a common finding in human and rat skeletal muscle pathology. Fiber splitting refers to longitudinal halving of the complete fiber, while branching originates from a regenerating end of a necrotic fiber as invaginations of the sarcolemma. In fiber branching, one end of the fiber remains intact as a single entity, while the other end has several branches. Evidence: IEA. (OMIM:609452)
- Polyneuropathy (HP:0001271): A generalized disorder of peripheral nerves. Evidence: IEA. (OMIM:609452)
- Late onset (HP:0003584): A type of adult onset with onset of symptoms after the age of 60 years. Evidence: TAS. (OMIM:609452)
- Progressive distal muscle weakness (HP:0009063): Progressively reduced strength of the distal musculature. Evidence: IEA. (OMIM:609452)
- Progressive proximal muscle weakness (HP:0009073): Lack of strength of the proximal muscles that becomes progressively more severe. Evidence: IEA. (OMIM:609452)
- Cardiomyopathy (HP:0001638): A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Evidence: IEA. (OMIM:609452)
- Autophagic vacuoles (HP:0003736): The lysosomal-vacuolar pathway has a role in the controlled intracellular digestion of macromolecules such as protein complexes and organelles. This feature refers to the presence of an abnormally increased number of autophagic vacuoles in muscle tissue. Evidence: IEA. (OMIM:609452)
- Myofibrillar myopathy (HP:0003715): Myofibrillar structural changes characterized by abnormal intracellular accumulation of the intermediate filament desmin and other proteins. Evidence: IEA. (OMIM:609452)
- 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: IEA. (OMIM:609452)
- Hyporeflexia of lower limbs (HP:0002600): Reduced intensity of muscle tendon reflexes in the lower limbs. Reflexes are elicited by stretching the tendon of a muscle, e.g., by tapping. Evidence: IEA. (OMIM:609452)
- EMG: myopathic abnormalities (HP:0003458): The presence of abnormal electromyographic patterns indicative of myopathy, such as small-short polyphasic motor unit potentials. Evidence: IEA. (OMIM:609452)
These phenotypes are associated with the disease myofibrillar myopathy 4 (OMIM:609452).