- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 2/2. (PMID:30215711)
- Flexion contracture (HP:0001371): A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints. Evidence: IEA. (OMIM:618414)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: PCS. Frequency: 2/2. (PMID:30215711)
- Hip contracture (HP:0003273): Lack of full passive range of motion (restrictions in flexion, extension, or other movements) of the hip joint resulting from structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules and/or skin. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: IEA. (OMIM:618414)
- 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: 2/2. (PMID:30215711)
- 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: 2/2. (PMID:30215711)
- Abnormal circulating creatine kinase activity (HP:0040081): Any deviation from the normal activity of creatine kinase in the blood circulation. Evidence: PCS. Frequency: 0/2. (PMID:30215711)
- 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: 2/2. (PMID:30215711)
- Type 1 muscle fiber predominance (HP:0003803): An abnormal predominance of type I muscle fibers (in general, this feature can only be observed on muscle biopsy). Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- 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: 1/2. (PMID:30215711)
- Proximal muscle weakness (HP:0003701): A lack of strength of the proximal muscles. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Death in infancy (HP:0001522): Death within the first 24 months of life. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Axial muscle weakness (HP:0003327): Reduced strength of the axial musculature (i.e., of the muscles of the head and neck, spine, and ribs). Evidence: PCS. Frequency: 2/2. (PMID:30215711)
- EMG: decremental response of compound muscle action potential to repetitive nerve stimulation (HP:0003403): A compound muscle action potential (CMAP) is a type of electromyography (EMG). CMAP refers to a group of almost simultaneous action potentials from several muscle fibers in the same area evoked by stimulation of the supplying motor nerve and are recorded as one multipeaked summated action potential. This abnormality refers to a greater than normal decrease in the amplitude during the course of the investigation. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- 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: 1/2. (PMID:30215711)
- Polyhydramnios (HP:0001561): The presence of excess amniotic fluid in the uterus during pregnancy. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Generalized muscle weakness (HP:0003324): Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Persistent head lag (HP:0032988): The Premie-Neuro and the Dubowitz Neurological Examination score head lag in the same manner. Scoring for both is as follows: 0 = head drops and stays back, 1 = tries to lift head but drops it back, 2 = able to lift head slightly, 3 = lifts head in line with body, and 4 = head in front of body. This term applies if head lag persists beyond an expected age at a level of 0 or 1. Persistent head lag beyond age 4 mo has been linked to poor outcomes. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Knee flexion contracture (HP:0006380): A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Nasogastric tube feeding (HP:0040288): The condition of inability to eat normally treated by placement of a thin tube through the nose into the stomach that is then used to carry food. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Decreased fetal movement (HP:0001558): An abnormal reduction in quantity or strength of fetal movements. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- 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:30215711)
- Respiratory insufficiency due to muscle weakness (HP:0002747). Evidence: PCS. Frequency: 2/2. (PMID:30215711)
- Elbow flexion contracture (HP:0002987): An elbow contracture that limits the ability of the elbow joint to be extended (straightened), meaning that the elbow is fixed in an flexed (bent) position. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Apnea (HP:0002104): Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- Neck muscle weakness (HP:0000467): Decreased strength of the neck musculature. Evidence: PCS. Frequency: 1/2. (PMID:30215711)
- 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:30215711)
These phenotypes are associated with the disease congenital myopathy with reduced type 2 muscle fibers (OMIM:618414).