- Achilles tendon contracture (HP:0001771): A contracture of the Achilles tendon. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Impaired mastication (HP:0005216): An abnormal reduction in the ability to masticate (chew), i.e., in the ability to crush and ground food in preparation for swallowing. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 1/9. (PMID:27745833)
- 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: 4/9. (PMID:10655510)
- Recurrent lower respiratory tract infections (HP:0002783): An increased susceptibility to lower respiratory tract infections as manifested by a history of recurrent lower respiratory tract infections. Evidence: PCS. Frequency: 4/9. (PMID:27745833)
- Distal joint hypermobility (HP:0020152): Lack of stability of a distal joint (e.g., finger). Evidence: PCS. Frequency: 2/9. (PMID:10655510)
- Difficulty climbing stairs (HP:0003551): Reduced ability to climb stairs. Evidence: PCS. Frequency: 8/9. (PMID:10655510)
- Scapular winging (HP:0003691): Abnormal protrusion of the scapula away from the surface of the back. Evidence: PCS. Frequency: 5/9. (PMID:10655510)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Limb muscle weakness (HP:0003690): Reduced strength and weakness of the muscles of the arms and legs. Evidence: PCS. Frequency: 9/9. (PMID:27745833)
- 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: 4/9. (PMID:27745833)
- Joint contracture of the 5th finger (HP:0009183): Chronic loss of joint motion in the 5th finger due to structural changes in non-bony tissue. The term camptodactyly of the 5th finger is used if the distal and/or proximal interphalangeal joints are affected. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Difficulty running (HP:0009046): Reduced ability to run. Evidence: PCS. (PMID:10655510)
- 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: 7/9. (PMID:10655510)
- Frequent falls (HP:0002359). Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 9/9. (PMID:27745833)
- Proximal muscle weakness (HP:0003701): A lack of strength of the proximal muscles. Evidence: PCS. (PMID:27745833)
- Pes planus (HP:0001763): A foot where the longitudinal arch of the foot is in contact with the ground or floor when the individual is standing; or, in a patient lying supine, a foot where the arch is in contact with the surface of a flat board pressed against the sole of the foot by the examiner with a pressure similar to that expected from weight bearing; or, the height of the arch is reduced. Evidence: PCS. Frequency: 5/9. (PMID:10655510)
- Spinal rigidity (HP:0003306): Reduced ability to move the vertebral column with a resulting limitation of neck and trunk flexion. Evidence: PCS. Frequency: 2/9. (PMID:10655510)
- Exotropia (HP:0000577): A form of strabismus with one or both eyes deviated outward. Evidence: PCS. Frequency: 1/9. (PMID:27745833)
- Generalized amyotrophy (HP:0003700): Generalized (diffuse, unlocalized) amyotrophy (muscle atrophy) affecting multiple muscles. Evidence: PCS. (PMID:27745833)
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 9/9. (PMID:27745833)
- Myopathic facies (HP:0002058): A facial appearance characteristic of myopathic conditions. The face appears expressionless with sunken cheeks, bilateral ptosis, and inability to elevate the corners of the mouth, due to muscle weakness. Evidence: PCS. Frequency: 9/9. (PMID:27745833)
- 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: 5/9. (PMID:27745833)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 7/9. (PMID:27745833)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 4/9. (PMID:27745833)
- Tall stature (HP:0000098): A height above that which is expected according to age and gender norms. Evidence: PCS. Frequency: 4/9. (PMID:27745833)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 2/9. (PMID:10655510)
- Easy fatigability (HP:0003388): Increased susceptibility to fatigue. Evidence: PCS. (PMID:27745833)
- Long face (HP:0000276): Facial height (length) is more than 2 standard deviations above the mean (objective); or, an apparent increase in the height (length) of the face (subjective). Evidence: PCS. Frequency: 4/9. (PMID:27745833)
- 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: 1/9. (PMID:10655510)
- Joint hypermobility (HP:0001382): The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes. Evidence: PCS. Frequency: 4/9. (PMID:27745833)
- 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: 1/9. (PMID:27745833)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. (PMID:27745833)
- Restrictive ventilatory defect (HP:0002091): A functional defect characterized by reduced total lung capacity (TLC) not associated with abnormalities of expiratory airflow or airway resistance. Spirometrically, a restrictive defect is defined as FEV1 (forced expiratory volume in 1 second) and FVC (forced vital capacity) less than 80 per cent. Restrictive lung disease may be caused by alterations in lung parenchyma or because of a disease of the pleura, chest wall, or neuromuscular apparatus. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- 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: 3/9. (PMID:10655510)
- Central core regions in muscle fibers (HP:0030230): The presence of disorganized areas called cores in the center of muscle fibers. There is a typical appearance of the biopsy on light microscopy, where the muscle cells have cores that are devoid of mitochondria and specific enzymes. Cores are typically well demarcated and centrally located, but may occasionally be multiple and of eccentric. Evidence: PCS. Frequency: 5/9. (PMID:27745833)
- Pectus excavatum (HP:0000767): A defect of the chest wall characterized by a depression of the sternum, giving the chest ("pectus") a caved-in ("excavatum") appearance. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Autosomal recessive inheritance (HP:0000007): 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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:27745833)
- Dental malocclusion (HP:0000689): Dental malocclusion refers to an abnormality of the occlusion, or alignment, of the teeth and the way the upper and lower teeth fit together, resulting in overcrowding of teeth or in abnormal bite patterns. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: PCS. Frequency: 1/9. (PMID:27745833)
- Mitral regurgitation (HP:0001653): An abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction. Evidence: PCS. Frequency: 1/9. (PMID:27745833)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: PCS. Frequency: 1/9. (PMID:10655510)
- Nemaline bodies (HP:0003798): Nemaline rods are abnormal bodies that can occur in skeletal muscle fibers. The rods can be observed on histological analysis of muscle biopsy tissue or upon electron microscopy, where they appear either as extensions of sarcomeric Z-lines, in random array without obvious attachment to Z-lines (often in areas devoid of sarcomeres) or in large clusters localized at the sarcolemma or intermyofibrillar spaces. Evidence: PCS. Frequency: 2/9. (PMID:27745833)
- Slowly progressive (HP:0003677): Applies to a disease manifestation that only slowly increases in scope or severity over the course of time. Evidence: PCS. (PMID:27745833)
- 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: 9/9. (PMID:10655510)
- Neck muscle weakness (HP:0000467): Decreased strength of the neck musculature. Evidence: PCS. Frequency: 2/9. (PMID:10655510)
These phenotypes are associated with the disease myofibrillar myopathy 8 (OMIM:617258).