This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
|Medical Terms||Other Names||
|5%-29% of people have these symptoms|
|Sensorineural hearing impairment||0000407|
|Percent of people who have these symptoms is not available through HPO|
Absent tendon reflexes
Involuntary writhing movements in fingers, hands, toes, and feet
Degeneration of cerebellum
|Cerebral cortical atrophy||
Decrease in size of the outer layer of the brain due to loss of brain cells
|Failure to thrive||
Weight faltering[ more ]
Decreased muscle tone
Low muscle tone[ more ]
|Hypoplasia of the
Underdevelopment of part of brain called corpus callosum
Decreased reflex response
Decreased reflexes[ more ]
Onset in first year of life
Onset in infancy[ more ]
|Intellectual disability, severe||
Early and severe mental retardation
Mental retardation, severe
Severe mental retardation[ more ]
Involuntary, rapid, rhythmic eye movements
Progressively abnormally small cranium
Progressively abnormally small skull[ more ]
Breakdown of light-sensitive cells in back of eye
|Severe global developmental delay||0011344|
Squint eyes[ more ]
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.
If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.
If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.
You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.
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.
Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.