The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
| Signs and Symptoms | Approximate number of patients (when available) |
| Cataract | 5% |
| Adult onset | - |
| Areflexia | - |
| Atrophy/Degeneration involving the spinal cord | - |
| Autosomal recessive inheritance | - |
| Cognitive impairment | - |
| Decreased activity of cytochrome C oxidase in muscle tissue | - |
| Depression | - |
| Dilated cardiomyopathy | - |
| Dysarthria | - |
| Gastroparesis | - |
| Hyporeflexia | - |
| Impaired distal proprioception | - |
| Impaired distal vibration sensation | - |
| Increased serum lactate | - |
| Increased variability in muscle fiber diameter | - |
| Intestinal pseudo-obstruction | - |
| Migraine | - |
| Mildly elevated creatine phosphokinase | - |
| Multiple mitochondrial DNA deletions | - |
| Muscle fiber necrosis | - |
| Myoclonus | - |
| Nystagmus | - |
| Phenotypic variability | - |
| Positive Romberg sign | - |
| Progressive external ophthalmoplegia | - |
| Progressive gait ataxia | - |
| Proximal muscle weakness | - |
| Ptosis | - |
| Ragged-red muscle fibers | - |
| Seizures | - |
| Sensorineural hearing impairment | - |
| Sensory ataxic neuropathy | - |
| Sensory axonal neuropathy | - |
| Subsarcolemmal accumulations of abnormally shaped mitochondria | - |
| Vestibular dysfunction | - |
Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.
The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.
Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
