- 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: 2/2. (PMID:38413182)
- Somatic sensory dysfunction (HP:0003474): An abnormality of the primary sensation that is mediated by peripheral nerves (pain, temperature, touch, vibration, joint position). The word hypoesthesia (or hypesthesia) refers to a reduction in cutaneous sensation to a specific type of testing. Evidence: PCS. Frequency: 0/2. (PMID:38413182)
- Scapular winging (HP:0003691): Abnormal protrusion of the scapula away from the surface of the back. Evidence: PCS. Frequency: 1/1. (PMID:38413182)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/2. (PMID:38413182)
- 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: 0/1. (PMID:38413182)
- Fatty replacement of skeletal muscle (HP:0012548): Muscle fibers degeneration resulting in fatty replacement of skeletal muscle fibers. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- Arrhythmia (HP:0011675): Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both. Evidence: PCS. Frequency: 0/1. (PMID:38413182)
- Proximal lower limb muscle weakness (HP:0008994): A lack of strength of the proximal muscles of the legs. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- 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: 2/2. (PMID:38413182)
- 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: 2/2. (PMID:38413182)
- High palate (HP:0000218): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- Ophthalmoparesis (HP:0000597): Ophthalmoplegia is a paralysis or weakness of one or more of the muscles that control eye movement. Evidence: PCS. Frequency: 1/1. (PMID:38413182)
- Proximal upper limb muscle weakness (HP:0008997): A lack of strength of the proximal muscles of the arms. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- 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: 2/2. (PMID:38413182)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 1/2. (PMID:38413182)
- 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: 1/2. (PMID:38413182)
- Distal upper limb muscle weakness (HP:0008959): Reduced strength of the distal musculature of the arms. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- Abnormal left ventricular function (HP:0005162): Inability of the left ventricle to perform its normal physiologic function. Failure is either due to an inability to contract the left ventricle or the inability to relax completely and fill with blood during diastole. Evidence: PCS. Frequency: 0/1. (PMID:38413182)
- Distal lower limb muscle weakness (HP:0009053): Reduced strength of the distal musculature of the legs. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- 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: 1/2. (PMID:38413182)
- Ophthalmoplegia (HP:0000602): Paralysis of one or more extraocular muscles that are responsible for eye movements. Evidence: PCS. Frequency: 0/2. (PMID:38413182)
- Abnormal nerve conduction velocity (HP:0040129). Evidence: PCS. Frequency: 0/2. (PMID:38413182)
- Diminished deep tendon reflex (HP:0001315): A reduction (hyporeflexia) or complete absence (areflexia) of the involuntary muscle contraction normally elicited by a reflex stimulus, such as tapping a deep tendon. Evidence: PCS. Frequency: 2/2. (PMID:38413182)
- 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:38413182)
- 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: 1/1. (PMID:38413182)
- 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:38413182)
- 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: 2/2. (PMID:38413182)
These phenotypes are associated with the disease congenital myopathy 26 (OMIM:621225).