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||
|80%-99% of people have these symptoms|
|Abnormal pyramidal sign||0007256|
|Abnormality of brainstem morphology||
Abnormal shape of brainstem
|Cortical visual impairment||0100704|
Loss of developmental milestones
Mental deterioration in childhood[ more ]
Diffuse skeletal muscle wasting
Generalized muscle degeneration
Muscle atrophy, generalized[ more ]
Hearing defect[ more ]
Early and severe mental retardation
Mental retardation, severe
Severe mental retardation[ more ]
Low or weak muscle tone
Involuntary muscle stiffness, contraction, or spasm
|30%-79% of people have these symptoms|
|Abnormality of extrapyramidal motor function||0002071|
Involuntary, rapid, rhythmic eye movements
Squint eyes[ more ]
|Telangiectasia of the skin||0100585|
|5%-29% of people have these symptoms|
|Aplasia/Hypoplasia of the cerebellum||
Absent/underdeveloped cerebellum[ more ]
Enlarged and thickened heart muscle
Pins and needles feeling
Tingling[ more ]
|Percent of people who have these symptoms is not available through HPO|
Decreased muscle tone
Low muscle tone[ more ]
|Increased urinary O-linked sialopeptides||0003461|
Onset in first year of life
Onset in infancy[ 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.
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.
Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
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.
NCATS Rare Diseases Are Not Rare! Challenge
October 9, 2018
The NIH Undiagnosed Diseases Network Expands
September 26, 2018
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. Submit a new question
I would like to know the exact location of the gene that causes this disease. In addition, can you tell me more about the mutation involved? See answer