Phenotypes associated with the disease Tay-Sachs disease AB variant (OMIM:272750):
- Exaggerated startle response (HP:0002267): An exaggerated startle reaction in response to a sudden unexpected visual or acoustic stimulus, or a quick movement near the face. Evidence: PCS. Frequency: 1/1. (PMID:9932959)
- 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: IEA. (OMIM:272750)
- 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: IEA. (OMIM:272750)
- 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. (OMIM:272750)
- GM2-ganglioside accumulation (HP:0003495): Cellular accumulation of GM2 gangliosides. Evidence: PCS. Frequency: 1/1. (PMID:9932959)
- 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: IEA. (OMIM:272750)
- 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: 1/1. (PMID:9932959)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:9932959)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:272750)
- Myoclonic seizure (HP:0032794): A myoclonic seizure is a type of motor seizure characterized by sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: PCS. Frequency: 1/1. (PMID:9932959)
- 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: IEA. (OMIM:272750)
- Neurodegeneration (HP:0002180): Progressive loss of neural cells and tissue. Evidence: TAS. (OMIM:272750)
- Blindness (HP:0000618): Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation. Evidence: IEA. (OMIM:272750)
- Aspiration (HP:0002835): Inspiration of a foreign object into the airway. Evidence: IEA. (OMIM:272750)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. (OMIM:272750)
- Axial hypotonia (HP:0008936): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: TAS. (OMIM:272750)
- Primitive reflex (HP:0002476): The primitive reflexes are a group of behavioral motor responses which are found in normal early development, are subsequently inhibited, but may be released from inhibition by cerebral, usually frontal, damage. They are thus part of a broader group of reflexes which reflect release phenomena, such as exaggerated stretch reflexes and extensor plantars. They do however involve more complex motor responses than such simple stretch reflexes, and are often a normal feature in the neonate or infant. Evidence: TAS. (OMIM:272750)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: TAS. (OMIM:272750)
- 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: 1/1. (PMID:9932959)
- Loss of speech (HP:0002371). Evidence: TAS. (OMIM:272750)
- Spastic tetraparesis (HP:0001285): Spastic weakness affecting all four limbs. Evidence: TAS. (OMIM:272750)
- 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. (OMIM:272750)
- Dementia (HP:0000726): A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior. Evidence: IEA. (OMIM:272750)
- Hyperacusis (HP:0010780): Over-sensitivity to certain frequency ranges of sound. Evidence: TAS. (OMIM:272750)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. (OMIM:272750)
- 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:1915858)
- Apathy (HP:0000741): Apathy is a quantitative reduction of interest, motivation and the initiation and persistence of goal-directed behavior, where often the accompanying emotions, thoughts, and social interactions are also diminished. The individual is typically non-reactive to provocations, positive or negative, and appears to not care. Distinguished from lethargy which involves lack of physical or mental energy. Evidence: IEA. (OMIM:272750)