- 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: 9/11. (PMID:34048612)
- Middle age onset (HP:0003596): A type of adult onset with onset of symptoms at the age of 40 to 60 years. Evidence: PCS. Frequency: 10/11. (PMID:34048612)
- Scapular winging (HP:0003691): Abnormal protrusion of the scapula away from the surface of the back. Evidence: PCS. Frequency: 10/10. (PMID:34048612)
- Fasciculations (HP:0002380): Fasciculations are observed as small, local, involuntary muscle contractions (twitching) visible under the skin. Fasciculations result from increased irritability of an axon (which in turn is often a manifestation of disease of a motor neuron). This leads to sporadic discharges of all the muscle fibers controlled by the axon in isolation from other motor units. Evidence: PCS. Frequency: 3/11. (PMID:34048612)
- Fiber type grouping (HP:0033685): An abnormal distribution of muscle fiber types in muscle tissue. Human skeletal muscle contains at least two fiber types recognizable by histochemical techniques. In transverse sections of normal skeletal muscle, type 1 and type 2 fibers are distributed in a random fashion. Grouping of fibers of the same type can be seen in certain peripheral neuropathies, thought to be due to reinnervation of denervated muscle fibers by sprouting axons. With grouping, motor units enlarge. The fibers of a motor unit, which are normally scattered, come to lie adjacent to one another. Histochemical examination shows groups of muscle fibers of the same histochemical type. Evidence: PCS. (PMID:34048612)
- Fatty replacement of skeletal muscle (HP:0012548): Muscle fibers degeneration resulting in fatty replacement of skeletal muscle fibers. Evidence: PCS. (PMID:34048612)
- 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: 3/11. (PMID:34048612)
- Increased endomysial connective tissue (HP:0100297): An increased volume of the endomysium, which is a connective tissue sheath that surrounds each muscle fiber. Together, bundles of muscle fibers form a fasciculus, surrounded by another layer of connective tissue called the perimysium. Evidence: PCS. (PMID:34048612)
- Cognitive impairment (HP:0100543): Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering. Evidence: PCS. Frequency: 3/11. (PMID:34048612)
- Abdominal wall muscle weakness (HP:0009023): Decreased strength of the abdominal musculature. Evidence: PCS. Frequency: 11/11. (PMID:34048612)
- Angulated muscle fibers (HP:0034045): Normal muscle fibers are polygonal-shaped in cross section, are multinucleated, and have minimal amounts of endomysial connective tissue. In contrast, angulated (also known as angular) muscle fibers have long and narrow vertices (corners) with sharp edges and a pointed tip. Evidence: PCS. (PMID:34048612)
- Proximal lower limb muscle weakness (HP:0008994): A lack of strength of the proximal muscles of the legs. Evidence: PCS. Frequency: 11/11. (PMID:34048612)
- Rimmed vacuoles (HP:0003805): Presence of abnormal vacuoles (membrane-bound organelles) in the sarcolemma. On histological staining with hematoxylin and eosin, rimmed vacuoles are popcorn-like clear vacuoles with a densely blue rim. The vacuoles are often associated with cytoplasmic and occasionally intranuclear eosinophilic inclusions. Evidence: PCS. (PMID:34048612)
- Late young adult onset (HP:0025710): Onset of disease at an age of greater than or equal to 25 to under 40 years. Evidence: PCS. Frequency: 1/11. (PMID:34048612)
- Proximal upper limb muscle weakness (HP:0008997): A lack of strength of the proximal muscles of the arms. Evidence: PCS. Frequency: 11/11. (PMID:34048612)
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 2/10. (PMID:34048612)
- EMG: positive sharp waves (HP:0030007): These are spontaneous firing action potentials stimulated by needle movement of an injured muscle fiber. There is propagation to, but not past, the needle tip. This inhibits the display of the negative deflection of the waveform. Evidence: PCS. Frequency: 4/11. (PMID:34048612)
- 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. (PMID:34048612)
- Babinski sign (HP:0003487): Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract. Evidence: PCS. Frequency: 1/11. (PMID:34048612)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 5/11. (PMID:34048612)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 6/11. (PMID:34048612)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: PCS. Frequency: 4/11. (PMID:34048612)
- Low back pain (HP:0003419): An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the lower back. Evidence: PCS. Frequency: 9/11. (PMID:34048612)
- Drooling (HP:0002307): Habitual flow of saliva out of the mouth. Evidence: PCS. Frequency: 2/11. (PMID:34048612)
- 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:34048612)
- 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. (PMID:34048612)
These phenotypes are associated with the disease inclusion body myopathy and brain white matter abnormalities (OMIM:619733).