- Hydrocephalus (HP:0000238): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Macrocephaly (HP:0000256): Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- 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: Very frequent (HP:0040281). (ORPHA:99966)
- 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: Very frequent (HP:0040281). (ORPHA:99966)
- 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:99966)
- 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: Frequent (HP:0040282). (ORPHA:99966)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Limitation of joint mobility (HP:0001376): A reduction in the freedom of movement of one or more joints. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Nausea and vomiting (HP:0002017): Nausea is a commonly encountered symptom that has been defined as an unpleasant painless subjective feeling that one will imminently vomit. Vomiting has been defined as the forceful expulsion of the contents of the stomach, duodenum, or jejunum through the oral cavity. While nausea and vomiting are often thought to exist on a temporal continuum, this is not always the case. There are situations when severe nausea may be present without emesis and less frequently, when emesis may be present without preceding nausea. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99966)
- Migraine (HP:0002076): Migraine is a chronic neurological disorder characterized by episodic attacks of headache and associated symptoms. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Cerebral calcification (HP:0002514): The presence of calcium deposition within the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:99966)
- Reduced consciousness (HP:0004372): Abnormally diminished level of attention, responsiveness, or wakefulness. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Hemiplegia/hemiparesis (HP:0004374): Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a severe or complete loss of strength, whereas hemiparesis refers to a relatively mild loss of strength. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99966)
- Cranial nerve paralysis (HP:0006824). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:99966)
- Cerebral palsy (HP:0100021): Cerebral palsy describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behavior, by epilepsy, and by secondary musculoskeletal problems. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:99966)
- Malignant neoplasm of the central nervous system (HP:0100836): A tumor that originates in the pineal gland, has moderate cellularity and tends to form rosette patterns. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99966)
These phenotypes are associated with the disease Atypical teratoid rhabdoid tumor (ORPHA:99966).