- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 1/4. (PMID:22065524)
- Peripheral axonal neuropathy (HP:0003477): An abnormality characterized by disruption of the normal functioning of peripheral axons. Evidence: PCS. Frequency: 3/4. (PMID:22065524)
- Progressive (HP:0003676): Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age. Evidence: PCS. (PMID:22065524)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 2/4. (PMID:22065524)
- 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: PCS. Frequency: 4/4. (PMID:22065524)
- 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: PCS. Frequency: 3/3. (PMID:22065524)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: PCS. Frequency: 4/4. (PMID:22065524)
- 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: PCS. Frequency: 4/4. (PMID:22065524)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: PCS. Frequency: 3/4. (PMID:22065524)
- 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: PCS. Frequency: 4/4. (PMID:22065524)
- Early young adult onset (HP:0025708): Onset of disease at an age of greater than or equal to 16 to under 19 years. Evidence: PCS. Frequency: 2/4. (PMID:22065524)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 3/4. (PMID:22065524)
- Oculomotor apraxia (HP:0000657): Ocular motor apraxia is a deficiency in voluntary, horizontal, lateral, fast eye movements (saccades) with retention of slow pursuit movements. The inability to follow objects visually is often compensated by head movements. There may be decreased smooth pursuit, and cancelation of the vestibulo-ocular reflex. Evidence: PCS. Frequency: 3/4. (PMID:22065524)
- Slow saccadic eye movements (HP:0000514): An abnormally slow velocity of the saccadic eye movements. Evidence: PCS. Frequency: 4/4. (PMID:22065524)
- Elevated circulating alpha-fetoprotein concentration (HP:0006254): The concentration of alpha-fetoprotein in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 4/4. (PMID:22065524)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:22065524)
- Distal sensory impairment (HP:0002936): An abnormal reduction in sensation in the distal portions of the extremities. Evidence: PCS. Frequency: 4/4. (PMID:22065524)
- Frequent falls (HP:0002359). Evidence: PCS. Frequency: 4/4. (PMID:22065524)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 3/4. (PMID:22065524)
These phenotypes are associated with the disease ataxia with oculomotor apraxia type 3 (OMIM:615217).