Phenotypes associated with the disease GM2 gangliosidosis, AB variant (ORPHA:309246):
- 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:309246)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Neurodegeneration (HP:0002180): Progressive loss of neural cells and tissue. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Progressive spastic quadriplegia (HP:0002478). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Axial hypotonia (HP:0008936): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Hyperacusis (HP:0010780): Over-sensitivity to certain frequency ranges of sound. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Cognitive impairment (HP:0100543): Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Abnormal fear-induced behavior (HP:0100852): An abnormal fear-induced behavior includes observable actions. This behavior is characterized by abnormal responses to fear or abnormal fear levels. Examples of such behavior include avoiding fear-inducing situations. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:309246)
- Inappropriate behavior (HP:0000719): An explicit or perceived action, demonstration, conduct, or language (verbal and written) that is contrary to generally accepted norms, rules, procedures, or unacceptable within the context in which it is carried out. Inappropriate behaviors could take place in a sexual or social context and could be aggressive, violent, impulsive, intimidating, or threatening in nature. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Anxiety (HP:0000739): Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- 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: Frequent (HP:0040282). (ORPHA:309246)
- 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:309246)
- Loss of speech (HP:0002371). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- 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. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Postnatal growth retardation (HP:0008897): Slow or limited growth after birth. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Cherry red spot of the macula (HP:0010729): Pallor of the perifoveal macula of the retina with appearance of a small circular reddish choroid shape as seen through the fovea centralis due to relative transparency of the macula. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Abnormal involuntary eye movements (HP:0012547): Anomalous movements of the eyes that occur without the subject wanting them to happen. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Glabellar reflex (HP:0030904): A type of primitive reflex that is elicited by repetitive tapping on the forehead. Normal subjects usually blink in response to the first several taps, but if blinking persists, the response is abnormal and considered to be a sign of frontal release. Persistent blinking is also known as Myerson's sign. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:309246)
- Pseudobulbar signs (HP:0002200): Pseudobulbar signs result from injury to an upper motor neuron lesion to the corticobulbar pathways in the pyramidal tract. Patients have difficulty chewing, swallowing and demonstrate slurred speech (often initial presentation) as well as abnormal behavioral symptoms such as inappropriate emotional outbursts of uncontrolled laughter or weeping etc. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:309246)
- Punctate periventricular T2 hyperintense foci (HP:0030081): Multiple pointlike areas of high T2 signal observed upon magnetic resonance imaging of the periventricular cerebral white matter. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:309246)