- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Mental deterioration (HP:0001268): Loss of previously present mental abilities, generally in adults. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:399)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:399)
- 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: Very frequent (HP:0040281). (ORPHA:399)
- Abnormality of eye movement (HP:0000496): An abnormality in voluntary or involuntary eye movements or their control. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Agitation (HP:0000713): A state of excessive motor activity that is associated with mental distress or a feeling of substantial unease or inner tension. Distinguished from restlessness by the increased level of emotional distress and negative intensity of the experience. Agitation has a significant level of physical activity that is typically threatening to the self or others. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Depression (HP:0000716): Frequently experiencing feelings of being down, miserable, and/or hopeless; struggling to recover from these moods; having a pessimistic outlook on the future; feeling a pervasive sense of shame; having a low self-worth; experiencing thoughts of suicide and engaging in suicidal behavior. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Aggressive behavior (HP:0000718): Behavior or an act aimed at harming a person, animal, or physical property (e.g., acts of physical violence; shouting, swearing, and using harsh language; slashing someone's tires). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Compulsive behaviors (HP:0000722): Behavior that consists of repetitive acts, characterized by the feeling that one "has to" perform them, while being aware that these acts are not in line with one's overall goal. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Disinhibition (HP:0000734): Reduced ability to control, or a failure to resist a temptation, urge, or impulse. Examples include disregard for social conventions, general impulsivity, and poor risk assessment. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Irritability (HP:0000737): An emotional state characterized by negative feelings of heightened frustration, annoyance, or feeling upset, often triggered by internal factors (e.g., fatigue, hunger, unfulfilled desires) or external factors (e.g., social or environmental challenges). Irritability may be unpredictable, and is accompanied by a lowered threshold for emotional reactivity and observable features (speech, facial expressions, or psychomotor activity). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Hallucinations (HP:0000738): Perceptions in a conscious and awake state that, in the absence of external stimuli, have qualities of real perception. These perceptions are vivid, substantial, and located in external objective space. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- 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:399)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Delusion (HP:0000746): A delusion is a fixed false belief held despite evidence to the contrary. The term delusion broadly encompasses all false judgments that possess the following external characteristics to a significant, albeit unspecified, extent: (1) they are held with an exceptional level of conviction, accompanied by an unparalleled subjective certainty; (2) there is an inability to consider alternative experiences or compelling counter-arguments; (3) the content of the belief is impossible. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- 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:399)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- 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: Frequent (HP:0040282). (ORPHA:399)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Weight loss (HP:0001824): Reduction of total body weight. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Bradykinesia (HP:0002067): Bradykinesia literally means slow movement, and is used clinically to denote a slowness in the execution of movement (in contrast to hypokinesia, which is used to refer to slowness in the initiation of movement). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Gait imbalance (HP:0002141). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Clumsiness (HP:0002312): Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Memory impairment (HP:0002354): An impairment of memory as manifested by a reduced ability to remember things such as dates and names, and increased forgetfulness. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Hypokinesia (HP:0002375): Abnormally diminished motor activity. In contrast to paralysis, hypokinesia is not characterized by a lack of motor strength, but rather by a poverty of movement. The typical habitual movements (e.g., folding the arms, crossing the legs) are reduced in frequency. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Generalized muscle weakness (HP:0003324): Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Involuntary movements (HP:0004305): Involuntary contractions of muscle leading to involuntary movements of extremities, neck, trunk, or face. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Abnormality of the sense of smell (HP:0004408): An anomaly in the ability to perceive and distinguish scents (odors). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Poor fine motor coordination (HP:0007010): An abnormality of the ability (skills) to perform a precise movement of small muscles with the intent to perform a specific act. Fine motor skills are required to mediate movements of the wrists, hands, fingers, feet, and toes. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Speech articulation difficulties (HP:0009088): Impairment in the physical production of speech sounds. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Staring gaze (HP:0025401): An abnormality in which the eyes are held permanently wide open. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Anger (HP:0031473): A state of excessive negative emotional reactivity characterized by strong feelings of hostility or antagonism typically in response to perceived provocation. It is often accompanied by physiological arousal (e.g., increased heart rate, muscle tension, or activation of the sympathetic nervous system) and expressions of blame, perceived injustice, or judgment. The experience of anger may be directed outwardly toward individuals, groups, objects, or abstract entities, or inwardly toward oneself. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Abnormally slow thought process (HP:0031843): An inner sense from the self that thoughts are abnormally slow and the individual feels that they are unable to increase their rate of thinking. The primary pathology is the decreased rate and other qualities of thinking (e.g. naming of objects) are intact, just slowed. This may be associated with slowed speech, but may be internal and masked by speech that is limited to brief (yes or no) answers. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Abnormal libido (HP:0031845): Any deviation from the normal sexual drive or desire for sexual activity. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:399)
- Excessive daytime somnolence (HP:0001262): A state of abnormally strong desire for sleep during the daytime. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Rigidity (HP:0002063): Continuous involuntary sustained muscle contraction. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Clonus (HP:0002169): A series of rhythmic and involuntary muscle contractions (at a frequency of about 5 to 7 Hz) that occur in response to an abruptly applied and sustained stretch. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Mutism (HP:0002300): Complete lack of speech or verbal communication in a person despite attempts to engage in conversation. Mutism as a phenomena assumes the individual has previous capacity for speech and in the pediatric population it assumes that the person is past the age of typical language development. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Caudate atrophy (HP:0002340). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Abnormal cerebral white matter morphology (HP:0002500): An abnormality of the cerebral white matter. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Polyphagia (HP:0002591): A neurological anomaly with gross overeating associated with an abnormally strong desire or need to eat. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Abnormal circulating cholesterol concentration (HP:0003107): Any deviation from the normal concentration of cholesterol in the blood circulation. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Babinski sign (HP:0003487): Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Impaired visuospatial constructive cognition (HP:0010794): Reduced ability affecting mainly visuospatial cognition which may be tested using pattern construction (for example by Differential Ability Scales, which test a person's strengths and weaknesses across a range of intellectual abilities). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Choking episodes (HP:0030842): Incidents in which a piece of food or other objects get stuck in the upper airway and provoke coughing, gagging, inability to talk, and difficulty breathing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Addictive alcohol use (HP:0030955): An addictive behavior is defined as drinking excessive amounts of alcohol over a prolonged period of time, having difficulty in reducing the amount of alcohol consumed, strongly desiring alcohol, and experiencing withdrawal symptoms when not drinking alcohol. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Suicidal ideation (HP:0031589): Frequent thoughts about or preoccupation with killing oneself. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Degeneration of the striatum (HP:0040140). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Decreased body mass index (HP:0045082): Abnormally decreased weight-to-height squared ratio, calculated by dividing the individual's weight in kilograms by the square of the individual's height in meters and used as an indicator of underweight compared to averages. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Insomnia (HP:0100785): Persistent difficulty in starting or maintaining sleep, or waking up earlier than desired, despite having adequate opportunities and conditions for sleep. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
- Oral-pharyngeal dysphagia (HP:0200136). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:399)
These phenotypes are associated with the disease Huntington disease (ORPHA:399).