- Gaze-evoked horizontal nystagmus (HP:0007979): Horizontal nystagmus made apparent by looking to the right or to the left. Evidence: PCS. Frequency: 3/10. (PMID:22901947)
- Strabismus (HP:0000486): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- Gaze-evoked nystagmus (HP:0000640): Nystagmus made apparent by looking to the right or to the left. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: PCS. Frequency: 7/10. Onset: Adult onset (HP:0003581). (PMID:22901947)
- 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: 11/11. (PMID:31319223;PMID:22901947)
- 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: PCS. Frequency: 2/10. (PMID:22901947)
- 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: 8/8. (PMID:31319223;PMID:22901947)
- Polyneuropathy (HP:0001271): A generalized disorder of peripheral nerves. Evidence: PCS. Frequency: 1/7. (PMID:22901947)
- Gait ataxia (HP:0002066): A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. (PMID:22901947)
- 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: 1/1. (PMID:31319223)
- Inferior cerebellar vermis hypoplasia (HP:0007068): Underdevelopment of the inferior portion of the vermis of cerebellum. Evidence: PCS. Frequency: 3/7. (PMID:22901947)
- Retrocerebellar cyst (HP:0006951). Evidence: PCS. Frequency: 5/7. (PMID:22901947)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: PCS. Frequency: 9/10. (PMID:22901947)
- Axial hypotonia (HP:0008936): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- Hypometric saccades (HP:0000571): Saccadic undershoot, i.e., a saccadic eye movement that has less than the magnitude that would be required to gain fixation of the object. Evidence: PCS. Frequency: 4/10. (PMID:22901947)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- 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: 5/5. (PMID:22901947)
- Dilated fourth ventricle (HP:0002198): An abnormal dilatation of the fourth cerebral ventricle. Evidence: PCS. Frequency: 4/7. (PMID:22901947)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Dysdiadochokinesis (HP:0002075): A type of ataxia characterized by the impairment of the ability to perform rapidly alternating movements, such as pronating and supinating his or her hand on the dorsum of the other hand as rapidly as possible. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Severe global developmental delay (HP:0011344): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: PCS. Frequency: 1/1. (PMID:31319223)
- Fatigue (HP:0012378): A subjective feeling of tiredness characterized by a lack of energy and motivation. Evidence: PCS. Frequency: 1/10. (PMID:22901947)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: PCS. Frequency: 3/10. (PMID:22901947)
- 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:22901947)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: PCS. (PMID:22901947)
- Esotropia (HP:0000565): A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more. Evidence: PCS. Frequency: 4/10. (PMID:22901947)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: PCS. Frequency: 10/10. (PMID:22901947)
- Slowly progressive (HP:0003677): Applies to a disease manifestation that only slowly increases in scope or severity over the course of time. Evidence: PCS. (PMID:22901947)
These phenotypes are associated with the disease autosomal recessive spinocerebellar ataxia 13 (OMIM:614831).