- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- Progressive spasticity (HP:0002191): Spasticity that increases in degree with time. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- GM2-ganglioside accumulation (HP:0003495): Cellular accumulation of GM2 gangliosides. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- Abnormality of glycolipid metabolism (HP:0010969): An abnormality of glycolipid metabolism. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- Abnormal circulating enzyme concentration or activity (HP:0012379): Concentration or activity of an enzyme is above or below the limits of normal in the blood circulation. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:845)
- Visual impairment (HP:0000505): Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Atypical behavior (HP:0000708): Atypical behavior is an abnormality in a person's actions that can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Short attention span (HP:0000736): Reduced attention span characterized by distractibility and impulsivity. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- 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:845)
- 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:845)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Gliosis (HP:0002171): Gliosis is the focal proliferation of glial cells in the central nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Postural instability (HP:0002172): A tendency to fall or the inability to keep oneself from falling; imbalance. The retropulsion test is widely regarded as the gold standard to evaluate postural instability, Use of the retropulsion test includes a rapid balance perturbation in the backward direction, and the number of balance correcting steps (or total absence thereof) is used to rate the degree of postural instability. Healthy subjects correct such perturbations with either one or two large steps, or without taking any steps, hinging rapidly at the hips while swinging the arms forward as a counterweight. In patients with balance impairment, balance correcting steps are often too small, forcing patients to take more than two steps. Taking three or more steps is generally considered to be abnormal, and taking more than five steps is regarded as being clearly abnormal. Markedly affected patients continue to step backward without ever regaining their balance and must be caught by the examiner (this would be called true retropulsion). Even more severely affected patients fail to correct entirely, and fall backward like a pushed toy soldier, without taking any corrective steps. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Incoordination (HP:0002311): A deficit in coordination of muscle movements. Coordination is defined as the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- 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:845)
- Frequent falls (HP:0002359). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Fasciculations (HP:0002380): Fasciculations are observed as small, local, involuntary muscle contractions (twitching) visible under the skin. Fasciculations result from increased irritability of an axon (which in turn is often a manifestation of disease of a motor neuron). This leads to sporadic discharges of all the muscle fibers controlled by the axon in isolation from other motor units. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Muscle spasm (HP:0003394): Sudden and involuntary contractions of one or more muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Difficulty climbing stairs (HP:0003551): Reduced ability to climb stairs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- 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:845)
- Hypointensity of cerebral white matter on MRI (HP:0007103): A darker than expected signal on magnetic resonance imaging emanating from the cerebral white matter. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Lower limb muscle weakness (HP:0007340): Weakness of the muscles of the legs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Quadriceps muscle atrophy (HP:0009050): Muscular atrophy involving the quadriceps muscle. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- 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:845)
- Aspiration pneumonia (HP:0011951): Pneumonia due to the aspiration (breathing in) of food, liquid, or gastric contents into the upper respiratory tract. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Abnormal thalamic MRI signal intensity (HP:0012696): A deviation from normal signal on magnetic resonance imaging (MRI) of the thalamus. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:845)
- Abnormality of eye movement (HP:0000496): An abnormality in voluntary or involuntary eye movements or their control. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Optic atrophy (HP:0000648): Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Psychosis (HP:0000709): A condition characterized by changes in personality and thought patterns, often accompanied by hallucinations and delusional beliefs, is known as psychosis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Dysmetria (HP:0001310): A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- 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:845)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Limited elbow extension (HP:0001377): Limited ability to straighten the arm at the elbow joint. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- Global brain atrophy (HP:0002283): Unlocalized atrophy of the brain with decreased total brain matter volume and increased ventricular size. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Drooling (HP:0002307): Habitual flow of saliva out of the mouth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- 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: Occasional (HP:0040283). (ORPHA:845)
- Focal impaired awareness seizure (HP:0002384): Focal impaired awareness seizure (or focal seizure with impaired or lost awareness) is a type of focal-onset seizure characterized by some degree (which may be partial) of impairment of the person's awareness of themselves or their surroundings at any point during the seizure. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Limited knee extension (HP:0003066): Reduced ability to extend (straighten) the knee joint. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Functional motor deficit (HP:0004302). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Progressive macrocephaly (HP:0004481): The progressive development of an abnormally large skull. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Distal upper limb muscle weakness (HP:0008959): Reduced strength of the distal musculature of the arms. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Speech articulation difficulties (HP:0009088): Impairment in the physical production of speech sounds. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Typical absence seizure (HP:0011147): A typical absence seizure is a type of generalized non-motor (absence) seizure characterized by its sudden onset, interruption of ongoing activities, a blank stare, possibly a brief upward deviation of the eyes. Usually the patient will be unresponsive when spoken to. Duration is a few seconds to half a minute with very rapid recovery. Although not always available, an EEG would usually show 3 Hz generalized epileptiform discharges during the event. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Ankle clonus (HP:0011448): Clonus is an involuntary tendon reflex that causes repeated flexion and extension of the foot. Ankle clonus is tested by rapidly flexing the foot upward. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Gastrostomy tube feeding in infancy (HP:0011471): Feeding problem necessitating gastrostomy tube feeding. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Laryngeal dystonia (HP:0012049): A form of focal dystonia that affects the vocal cords, associated with involuntary contractions of the vocal cords causing interruptions of speech and affecting the voice quality and often leading to patterned, repeated breaks in speech. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Hip flexor weakness (HP:0012515): Reduced ability to flex the femur, that is, to pull the knee upward. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Mania (HP:0100754): A state of abnormally elevated or irritable mood, arousal, and/or energy levels. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:845)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:845)
- Precocious puberty (HP:0000826): The onset of secondary sexual characteristics before a normal age. Although it is difficult to define normal age ranges because of the marked variation with which puberty begins in normal children, precocious puberty can be defined as the onset of puberty before the age of 8 years in girls or 9 years in boys. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:845)
- Elevated circulating beta-hexosaminidase activity (HP:0003333): The activity of beta-hexosaminidase in the blood circulation is above the upper limit of normal. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:845)
- Decerebrate rigidity (HP:0025013): A type of rigidity that is manifested by an exaggerated extensor posture of all extremities. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:845)
- Vegetative state (HP:0031358): The absence of wakefulness and consciousness, but in contrast to a coma, there is involuntary opening of the eyes and movements such as teeth grinding, yawning, or thrashing of the extremities. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:845)
These phenotypes are associated with the disease Tay-Sachs disease (ORPHA:845).
The following phenotypes are NOT associated with this disease:
- Hepatosplenomegaly (HP:0001433): Simultaneous enlargement of the liver and spleen. Evidence: TAS. (ORPHA:845)