Phenotypes associated with the disease Classic glucose transporter type 1 deficiency syndrome (ORPHA:71277):
- Progressive microcephaly (HP:0000253): Progressive microcephaly is diagnosed when the head circumference falls progressively behind age- and gender-dependent norms. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Encephalopathy (HP:0001298): Encephalopathy is a term that means brain disease, damage, or malfunction. In general, encephalopathy is manifested by an altered mental state. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Dystonia (HP:0001332): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Abnormal erythrocyte morphology (HP:0001877): Any structural abnormality of erythrocytes (red-blood cells). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Status epilepticus (HP:0002133): Status epilepticus is a type of prolonged seizure resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures (after time point t1). It is a condition that can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- EEG abnormality (HP:0002353): Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Hypoglycorrhachia (HP:0011972): Abnormally low glucose concentration in the cerebrospinal fluid. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:71277)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Cyanosis (HP:0000961): Bluish discoloration of the skin and mucosa due to poor circulation or inadequate oxygenation of arterial or capillary blood. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Lethargy (HP:0001254): A state of fatigue, either physical or mental slowness and sluggishness, with difficulties in initiating or performing simple tasks. Distinguished from apathy which implies indifference and a lack of desire or interest in the task. A person with lethargy may have the desire, but not the energy to engage in personal or socially relevant tasks. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Choreoathetosis (HP:0001266): Involuntary movements characterized by both athetosis (inability to sustain muscles in a fixed position) and chorea (widespread jerky arrhythmic movements). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Hemiparesis (HP:0001269): Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Hypertonia (HP:0001276): A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Confusion (HP:0001289): Lack of clarity and coherence of thought, perception, understanding, or action. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Chorea (HP:0002072): Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Headache (HP:0002315): Cephalgia, or pain sensed in various parts of the head, not confined to the area of distribution of any nerve. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Paralysis (HP:0003470): Paralysis of voluntary muscles means loss of contraction due to interruption of one or more motor pathways from the brain to the muscle fibers. Although the word paralysis is often used interchangeably to mean either complete or partial loss of muscle strength, it is preferable to use paralysis or plegia for complete or severe loss of muscle strength, and paresis for partial or slight loss. Motor paralysis results from deficits of the upper motor neurons (corticospinal, corticobulbar, or subcorticospinal). Motor paralysis is often accompanied by an impairment in the facility of movement. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Muscle stiffness (HP:0003552): A condition in which muscles cannot be moved quickly without accompanying pain or spasm. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Generalized hyperreflexia (HP:0007034). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Extrapyramidal dyskinesia (HP:0007308). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Paroxysmal involuntary eye movements (HP:0007704): Sudden-onset episode of abnormal, involuntary eye movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Dyskinesia (HP:0100660): A movement disorder which consists of effects including diminished voluntary movements and the presence of involuntary movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:71277)
- Strabismus (HP:0000486): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:71277)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:71277)
- Apraxia (HP:0002186): A defect in the understanding of complex motor commands and in the execution of certain learned movements, i.e., deficits in the cognitive components of learned movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:71277)
- Sleep disturbance (HP:0002360): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:71277)
- Central apnea (HP:0002871): Apnea resulting from depression of the respiratory centers in the medulla oblongata. There is a lack of respiratory effort rather than obstruction of airflow. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:71277)