- Broad-based gait (HP:0002136): An abnormal gait pattern in which persons stand and walk with their feet spaced widely apart. This is often a component of cerebellar ataxia. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Diplopia (HP:0000651): Diplopia is a condition in which a single object is perceived as two images, it is also known as double vision. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- 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: 1/1. (PMID:29290614)
- 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: 1/1. (PMID:29290614)
- Progressive external ophthalmoplegia (HP:0000590): Initial bilateral ptosis followed by limitation of eye movements in all directions and slowing of saccades. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- 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: 1/1. (PMID:29290614)
- Late onset (HP:0003584): A type of adult onset with onset of symptoms after the age of 60 years. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- 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:29290614)
- Arrhythmia (HP:0011675): Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Nasal regurgitation (HP:0011469): Regurgitation of milk through the nose. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Mildly reduced left ventricular ejection fraction (HP:0012663): A small reduction in the fraction of blood pumped from the left ventricle with each cardiac cycle. The normal range in adults is at least 50 percent, and a mild reduction is defined as 40-49 percent. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Sensorineural hearing impairment (HP:0000407): A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- 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: 1/1. (PMID:29290614)
- 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:29290614)
- Proximal muscle weakness (HP:0003701): A lack of strength of the proximal muscles. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Sensory neuropathy (HP:0000763): Peripheral neuropathy affecting the sensory nerves. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Exercise intolerance (HP:0003546): A functional motor deficit where individuals whose responses to the challenges of exercise fail to achieve levels considered normal for their age and gender. Evidence: PCS. Frequency: 1/1. (PMID:29290614)
- Neck flexor weakness (HP:0003722): Weakness of the muscles involved in neck flexion (sternocleidomastoid, longus capitus, longus colli, and scalenus anterior). Evidence: PCS. Frequency: 1/1. (PMID:29290614)
These phenotypes are associated with the disease progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 5 (OMIM:618098).