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) |
| Chorioretinal abnormality | Very frequent (present in 80%-99% of cases) |
| Constipation | Very frequent (present in 80%-99% of cases) |
| Macular dystrophy | Very frequent (present in 80%-99% of cases) |
| Malabsorption | Very frequent (present in 80%-99% of cases) |
| Sensorineural hearing impairment | Very frequent (present in 80%-99% of cases) |
| Type II diabetes mellitus | Very frequent (present in 80%-99% of cases) |
| Abnormality of lipid metabolism | Frequent (present in 30%-79% of cases) |
| Aplasia/Hypoplasia of the cerebellum | Frequent (present in 30%-79% of cases) |
| Arrhythmia | Frequent (present in 30%-79% of cases) |
| Congestive heart failure | Frequent (present in 30%-79% of cases) |
| External ophthalmoplegia | Frequent (present in 30%-79% of cases) |
| Glomerulopathy | Frequent (present in 30%-79% of cases) |
| Hypertension | Frequent (present in 30%-79% of cases) |
| Hypertrophic cardiomyopathy | Frequent (present in 30%-79% of cases) |
| Myalgia | Frequent (present in 30%-79% of cases) |
| Proteinuria | Frequent (present in 30%-79% of cases) |
| Ataxia | Occasional (present in 5%-29% of cases) |
| Cardiomyopathy | Occasional (present in 5%-29% of cases) |
| Cataract | Occasional (present in 5%-29% of cases) |
| Ptosis | Occasional (present in 5%-29% of cases) |
| Renal insufficiency | Occasional (present in 5%-29% of cases) |
| Retinopathy | Occasional (present in 5%-29% of cases) |
| Visual impairment | Occasional (present in 5%-29% of cases) |
| Dysarthria | - |
| Hyperglycemia | - |
| Mitochondrial inheritance | - |
| Pigmentary retinal degeneration | - |
| Retinal degeneration | - |
| Seizures | - |
| Unsteady gait | - |
| Vertigo | - |
Most of the body's cells contain thousands of mitochondria, each with one or more copies of mitochondrial DNA. These cells can have a mix of mitochondria containing mutated and unmutated DNA (heteroplasmy). The severity of MIDD is thought to be associated with the percentage of mitochondria with the mitochondrial DNA mutation.[1]
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.
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.
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