- Poor head control (HP:0002421): Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Epicanthus (HP:0000286): A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Bilateral tonic-clonic seizure (HP:0002069): A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Chorioretinal lacunae (HP:0007858): Punched out lesions in the pigmented layer of the retina. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- 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: 1/4. (PMID:31256877)
- Retinal pigment epithelial mottling (HP:0007814): Mottling (spots or blotches of different shades) of the retinal pigment epithelium, i.e., localized or generalized fundus pigment granularity associated with processes at the level of the retinal pigment epithelium. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Agenesis of corpus callosum (HP:0001274): Absence of the corpus callosum as a result of the failure of the corpus callosum to develop, which can be the result of a failure in any one of the multiple steps of callosal development including cellular proliferation and migration, axonal growth or glial patterning at the midline. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 2/4. (PMID:31256877)
- Sensory axonal neuropathy (HP:0003390): An axonal neuropathy of peripheral sensory nerves. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Infantile spasms (HP:0012469): Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy). Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Peripheral hypomyelination (HP:0007182): Reduced amount of myelin in the nervous system resulting from defective myelinogenesis in the peripheral nervous system. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Periventricular heterotopia (HP:0007165): A form of gray matter heterotopia were the mislocalized gray matter is typically located periventricularly, also sometimes called subependymal heterotopia. Periventricular means beside the ventricles. This is by far the most common location for heterotopia. Subependymal heterotopia present in a wide array of variations. There can be a small single node or a large number of nodes, can exist on either or both sides of the brain at any point along the higher ventricle margins, can be small or large, single or multiple, and can form a small node or a large wavy or curved mass. Evidence: PCS. (PMID:31256877)
- Slow saccadic eye movements (HP:0000514): An abnormally slow velocity of the saccadic eye movements. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Unsteady gait (HP:0002317). Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Aspiration (HP:0002835): Inspiration of a foreign object into the airway. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: PCS. (PMID:31256877)
- Posteriorly rotated ears (HP:0000358): A type of abnormal location of the ears in which the position of the ears is characterized by posterior rotation (the superior part of the ears is rotated towards the back of the head, and the inferior part of the ears towards the front). Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Simple ear (HP:0020206): The pinna has fewer folds and grooves than usual. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Talipes equinovarus (HP:0001762): Talipes equinovarus (also called clubfoot) typically has four main components: inversion and adduction of the forefoot; inversion of the heel and hindfoot; equinus (limitation of extension) of the ankle and subtalar joint; and internal rotation of the leg. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Reduced renal corticomedullary differentiation (HP:0005565): Reduced differentiation between renal cortex and medulla on diagnostic imaging. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Respiratory distress (HP:0002098): Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: PCS. Frequency: 2/2. (PMID:31256877)
- Multiple renal cysts (HP:0005562): The presence of many cysts in the kidney. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- 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: 1/4. (PMID:31256877)
- Sensorineural hearing impairment (HP:0000407): A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Calf muscle hypertrophy (HP:0008981): Muscle hypertrophy affecting the calf muscles. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Decreased amplitude of sensory action potentials (HP:0007078): A reduction in the amplitude of sensory nerve action potential. This feature is measured by nerve conduction studies. Evidence: PCS. (PMID:31256877)
- Wrist flexion contracture (HP:0001239): A chronic loss of wrist joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevent normal movement of the joints of the wrist. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- Decreased nerve conduction velocity (HP:0000762): A reduction in the speed at which electrical signals propagate along the axon of a neuron. Evidence: PCS. (PMID:31256877)
- Muscle fiber necrosis (HP:0003713): Abnormal cell death involving muscle fibers usually associated with break in, or absence of, muscle surface fiber membrane and resulting in irreversible damage to muscle fibers. Evidence: PCS. Frequency: 1/4. (PMID:31256877)
- 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:31256877)
- 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: 1/4. (PMID:31256877)
These phenotypes are associated with the disease neuromuscular disease and ocular or auditory anomalies with or without seizures (OMIM:618733).