- Type 2 muscle fiber atrophy (HP:0003554): Atrophy (wasting) affecting primary type 2 muscle fibers. This feature in general can only be observed on muscle biopsy. Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Achilles tendon contracture (HP:0001771): A contracture of the Achilles tendon. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- 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: 6/7. (PMID:32165108;PMID:39548192;PMID:28501893)
- 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: PCS. Frequency: 4/4. (PMID:26718575;PMID:39548192;PMID:28501893)
- Decreased motor nerve conduction velocity (HP:0003431): A type of decreased nerve conduction velocity that affects the motor neuron. Evidence: PCS. Frequency: 0/5. (PMID:28501893)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- 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: 10/15. (PMID:33744911;PMID:31403083;PMID:26718575;PMID:28501893)
- Difficulty climbing stairs (HP:0003551): Reduced ability to climb stairs. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Muscle spasm (HP:0003394): Sudden and involuntary contractions of one or more muscles. Evidence: PCS. Frequency: 1/1. (PMID:26718575)
- 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: 0/1. (PMID:26718575)
- Brachioradialis hyporeflexia (HP:0033202): Reduced intensity of the brachioradialis tendon reflex. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Fatty replacement of skeletal muscle (HP:0012548): Muscle fibers degeneration resulting in fatty replacement of skeletal muscle fibers. Evidence: PCS. Frequency: 6/6. (PMID:33744911;PMID:31403083;PMID:26718575;PMID:32165108;PMID:28501893)
- 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. Frequency: 1/1. (PMID:26718575)
- Biceps hyporeflexia (HP:0033201): Reduced intensity of the biceps tendon reflex. Evidence: PCS. Frequency: 2/2. (PMID:31403083)
- 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. Frequency: 1/1. (PMID:31403083)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 6/15. (PMID:33744911;PMID:31403083;PMID:32165108;PMID:28501893)
- Lumbar hyperlordosis (HP:0002938): An abnormal accentuation of the inward curvature of the spine in the lumbar region. Evidence: PCS. Frequency: 2/2. (PMID:31403083;PMID:32165108)
- Foot dorsiflexor weakness (HP:0009027): Weakness of the muscles responsible for dorsiflexion of the foot, that is, of the movement of the toes towards the shin. The foot dorsiflexors include the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the peroneus tertius muscles. Evidence: PCS. Frequency: 7/7. (PMID:31403083;PMID:26718575;PMID:28501893)
- Shoulder girdle muscle weakness (HP:0003547): The shoulder, or pectoral, girdle is composed of the clavicles and the scapulae. Shoulder-girdle weakness refers to lack of strength of the muscles attaching to these bones, that is, lack of strength of the muscles around the shoulders. Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Spinal rigidity (HP:0003306): Reduced ability to move the vertebral column with a resulting limitation of neck and trunk flexion. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- 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:28501893)
- 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: 1/1. (PMID:39548192)
- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Neurogenic bladder (HP:0000011): A type of bladder dysfunction caused by neurologic damage. Neurogenic bladder can be flaccid or spastic. Common manifestatios of neurogenic bladder are overflow incontinence, frequency, urgency, urge incontinence, and retention. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- 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: 5/5. (PMID:31403083;PMID:26718575;PMID:39548192;PMID:28501893)
- EMG: neuropathic changes (HP:0003445): The presence of characteristic findings of denervation on electromyography (fibrillations, positive sharp waves, and giant motor unit potentials). Evidence: PCS. Frequency: 1/1. (PMID:26718575)
- Decreased patellar reflex (HP:0011808): Decreased intensity of the patellar reflex (also known as the knee jerk reflex). Evidence: PCS. Frequency: 2/2. (PMID:31403083)
- Reduced vital capacity (HP:0002792): An abnormal reduction on the vital capacity, which is defined as the total lung capacity (volume of air in the lungs at maximal inflation) less the residual volume (i.e., volume of air in the lungs following maximal exhalation) of the lung. Evidence: PCS. Frequency: 0/1. (PMID:33744911)
- Impaired tactile sensation (HP:0010830): A reduced sense of touch (tactile sensation). This is usually tested with a wisp of cotton or a fine camel's hair brush, by asking patients to say 'now' each time they feel the stimulus. Evidence: PCS. Frequency: 0/3. (PMID:31403083;PMID:26718575;PMID:32165108)
- Joint contracture (HP:0034392): A limitation in the passive range of motion of a joint resulting from loss of elasticity in the periarticular tissues owing to structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules or skin. A contracture prevents movement of the associated body part. Evidence: PCS. Frequency: 1/1. (PMID:32165108)
- Distal lower limb muscle weakness (HP:0009053): Reduced strength of the distal musculature of the legs. Evidence: PCS. Frequency: 9/9. (PMID:31403083;PMID:26718575;PMID:32165108;PMID:28501893)
- Loss of ambulation (HP:0002505): Inability to walk in a person who previous had the ability to walk. Evidence: PCS. Frequency: 0/5. (PMID:28501893)
- Impaired heel-walking ability (HP:6000490): Difficulty or reduced ability to walk on heels. Heel-walking can be tested as a part of the neurological examination. Foot dorsal extension weakness leads to difficulties in walking on heels. Evidence: PCS. Frequency: 1/1. (PMID:26718575)
- Absent Achilles reflex (HP:0003438): Absence of the Achilles reflex (also known as the ankle jerk reflex), which can normally be elicited by tapping the tendon is tapped while the foot is dorsiflexed. Evidence: PCS. Frequency: 2/2. (PMID:31403083)
- 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:26718575)
- 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: 3/3. (PMID:33744911;PMID:31403083;PMID:39548192)
- Asthenia (HP:0025406): A state characterized by a feeling of weakness and loss of strength leading to a generalized weakness of the body. Evidence: PCS. Frequency: 2/2. (PMID:31403083;PMID:32165108)
- Hyperuricemia (HP:0002149): The concentration of uric acid in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Hand muscle weakness (HP:0030237): Reduced strength of the musculature of the hand. Evidence: PCS. Frequency: 2/2. (PMID:31403083)
- Steppage gait (HP:0003376): An abnormal gait pattern that arises from weakness of the pretibial and peroneal muscles due to a lower motor neuron lesion. Affected patients have footdrop and are unable to dorsiflex and evert the foot. The leg is lifted high on walking so that the toes clear the ground, and there may be a slapping noise when the foot strikes the ground again. Evidence: PCS. Frequency: 3/3. (PMID:31403083;PMID:26718575)
- Proximal upper limb amyotrophy (HP:0008948): Muscular atrophy affecting proximally located muscles of the arms. Evidence: PCS. Frequency: 1/1. (PMID:26718575)
- Scapular winging (HP:0003691): Abnormal protrusion of the scapula away from the surface of the back. Evidence: PCS. Frequency: 4/5. (PMID:31403083;PMID:26718575;PMID:32165108;PMID:39548192)
- Limited neck flexion (HP:0005991): Reduced ability to lower the chin towards the chest by bending the neck. Evidence: PCS. Frequency: 1/1. (PMID:32165108)
- Atelectasis (HP:0100750): Collapse of part of a lung associated with absence of inflation (air) of that part. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Camptocormia (HP:0100595): An abnormal forward-flexed posture e.g. forward flexion of the spine, which is noticeable when standing or walking but disappears when lying down. It is becoming an increasingly recognized feature of Parkinson's disease and dystonic disorders. Evidence: PCS. Frequency: 5/7. (PMID:31403083;PMID:32165108;PMID:28501893)
- Diabetes mellitus (HP:0000819): A group of abnormalities characterized by hyperglycemia and glucose intolerance. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Lower limb muscle weakness (HP:0007340): Weakness of the muscles of the legs. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- Reduced forced vital capacity (HP:0032341): An abnormal reduction in the amount of air a person can expel following maximal inspiration. Evidence: PCS. Frequency: 3/7. (PMID:33744911;PMID:31403083;PMID:32165108;PMID:39548192)
- Proximal lower limb muscle weakness (HP:0008994): A lack of strength of the proximal muscles of the legs. Evidence: PCS. Frequency: 6/6. (PMID:32165108;PMID:28501893)
- 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. Frequency: 6/6. (PMID:33744911;PMID:31403083;PMID:26718575;PMID:32165108;PMID:28501893)
- Waddling gait (HP:0002515): Weakness of the hip girdle and upper thigh muscles, for instance in myopathies, leads to an instability of the pelvis on standing and walking. If the muscles extending the hip joint are affected, the posture in that joint becomes flexed and lumbar lordosis increases. The patients usually have difficulties standing up from a sitting position. Due to weakness in the gluteus medius muscle, the hip on the side of the swinging leg drops with each step (referred to as Trendelenburg sign). The gait appears waddling. The patients frequently attempt to counteract the dropping of the hip on the swinging side by bending the trunk towards the side which is in the stance phase (in the German language literature this is referred to as Duchenne sign). Similar gait patterns can be caused by orthopedic conditions when the origin and the insertion site of the gluteus medius muscle are closer to each other than normal, for instance due to a posttraumatic elevation of the trochanter or pseudarthrosis of the femoral neck. Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Respiratory failure (HP:0002878): A severe form of respiratory insufficiency characterized by inadequate gas exchange such that the levels of oxygen or carbon dioxide cannot be maintained within normal limits. Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Foot pain (HP:0025238): An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the foot. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Abnormality of the cardiovascular system (HP:0001626): Any abnormality of the cardiovascular system. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Proximal upper limb muscle weakness (HP:0008997): A lack of strength of the proximal muscles of the arms. Evidence: PCS. Frequency: 6/6. (PMID:39548192;PMID:28501893)
- Elevated circulating hepatic transaminase concentration (HP:0002910): Elevations of the levels of SGOT and SGPT in the serum. SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) are transaminases primarily found in the liver and heart and are released into the bloodstream as the result of liver or heart damage. SGOT and SGPT are used clinically mainly as markers of liver damage. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Limb-girdle muscle weakness (HP:0003325): Weakness of the limb-girdle muscles (also known as the pelvic and shoulder girdles), that is, lack of strength of the muscles around the shoulders and the pelvis. Evidence: PCS. Frequency: 1/1. (PMID:33744911)
- Neck flexor weakness (HP:0003722): Weakness of the muscles involved in neck flexion (sternocleidomastoid, longus capitus, longus colli, and scalenus anterior). Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: PCS. Frequency: 5/5. (PMID:33744911;PMID:31403083)
- Pes cavus (HP:0001761): An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight). Evidence: PCS. Frequency: 1/3. (PMID:31403083;PMID:39548192)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 1/1. (PMID:32165108)
- Respiratory insufficiency (HP:0002093). Evidence: PCS. Frequency: 3/5. (PMID:33744911)
- Sleep apnea (HP:0010535): An intermittent cessation of airflow at the mouth and nose during sleep is known as sleep apnea. Apneas that last at least 10 seconds are considered significant, but individuals with sleep apnea may experience apneas lasting from 20 seconds up to 2 or 3 minutes. Patients may have up to 15 events per hour of sleep. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Mildly elevated creatine kinase (HP:0008180). Evidence: PCS. Frequency: 1/1. (PMID:26718575)
- Calf muscle hypertrophy (HP:0008981): Muscle hypertrophy affecting the calf muscles. Evidence: PCS. Frequency: 1/1. (PMID:39548192)
- Triceps hyporeflexia (HP:0033200): Reduced intensity of the triceps tendon reflex. Evidence: PCS. Frequency: 2/2. (PMID:31403083)
- Peripheral neuropathy (HP:0009830): Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Hypertension (HP:0000822): The presence of chronic increased pressure in the systemic arterial system. Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- 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: PCS. Frequency: 0/1. (PMID:31403083)
- Falls (HP:0002527). Evidence: PCS. Frequency: 1/1. (PMID:31403083)
- Abnormal nerve conduction velocity (HP:0040129). Evidence: PCS. Frequency: 0/2. (PMID:33744911;PMID:32165108)
- 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: 2/2. (PMID:26718575;PMID:39548192)
These phenotypes are associated with the disease myopathy, myofibrillar, 13, with rimmed vacuoles (OMIM:621078).