Phenotypes associated with the disease spinal muscular atrophy, infantile, James type (OMIM:619042):
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 2/3. (PMID:17101916;PMID:22462675)
- Delayed ability to walk (HP:0031936): A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months. Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: PCS. Frequency: 2/2. (PMID:22462675)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- 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: 1/1. (PMID:17101916)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 3/3. (PMID:17101916;PMID:22462675)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 3/3. (PMID:17101916;PMID:22462675)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 2/2. (PMID:22462675)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 2/2. (PMID:22462675)
- Respiratory insufficiency (HP:0002093). Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- Muscle fibrillation (HP:0010546): Fine, rapid twitching of individual muscle fibers with little or no movement of the muscle as a whole as ascertained by electromyography (EMG). If a motor neuron or its axon is destroyed, the muscle fibers it innervates undergo denervation atrophy. This leads to hypersensitivity of individual muscle fibers to acetyl choline so that they may contract spontaneously. Isolated activity of individual muscle fibers is generally so fine it cannot be seen through the intact skin, although it can be recorded as a short-duration spike in the EMG. Evidence: PCS. Frequency: 1/1. (PMID:22462675)
- Lower limb muscle weakness (HP:0007340): Weakness of the muscles of the legs. Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- Lumbar hyperlordosis (HP:0002938): An abnormal accentuation of the inward curvature of the spine in the lumbar region. Evidence: PCS. Frequency: 3/3. (PMID:17101916;PMID:22462675)
- 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: 1/1. (PMID:22462675)
- Weak voice (HP:0001621): Reduced intensity (volume) of speech. Evidence: PCS. Frequency: 1/1. (PMID:17101916)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 2/2. (PMID:22462675)
- 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:17101916)
- 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: 1/1. (PMID:22462675)