- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:99852)
- Anorexia (HP:0002039): Lack of desire to eat (loss of appetite). Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:99852)
- Progressive encephalopathy (HP:0002448). Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:99852)
- Decreased body weight (HP:0004325): Abnormally low body weight. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:99852)
- Abnormal posterior cranial fossa morphology (HP:0000932): An abnormality of the fossa cranii posterior (the posterior fossa), which is made up primarily of the occipital bone and which surrounds to the foramen magnum. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99852)
- 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: Very frequent (HP:0040281). (ORPHA:99852)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99852)
- Abnormal basal ganglia morphology (HP:0002134): Abnormality of the basal ganglia. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99852)
- Abnormal brainstem morphology (HP:0002363): An anomaly of the brainstem. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99852)
- Atrophy/Degeneration affecting the brainstem (HP:0007366). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:99852)
- Abnormality of eye movement (HP:0000496): An abnormality in voluntary or involuntary eye movements or their control. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99852)
- Abnormal auditory evoked potentials (HP:0006958): An abnormality of the auditory evoked potentials, which are used to trace the signal generated by a sound, from the cochlear nerve, through the lateral lemniscus, to the medial geniculate nucleus, and to the cortex. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:99852)
- Abnormality of the larynx (HP:0001600): An abnormality of the larynx. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:99852)
- Apnea (HP:0002104): Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:99852)
These phenotypes are associated with the disease Ravine syndrome (ORPHA:99852).