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|
|Failure to thrive||
Weight faltering[ more ]
|Feeding difficulties in infancy||0008872|
|Megaloblastic bone marrow||0001980|
Low or weak muscle tone
Inflammation of the mouth
|30%-79% of people have these symptoms|
Loss of developmental milestones
Mental deterioration in childhood[ more ]
|Percent of people who have these symptoms is not available through HPO|
High blood cystathionine levels
High urine cystathionine levels
|Decreased methionine synthase activity||0003524|
Prominent eye folds[ more ]
Decreased muscle tone
Low muscle tone[ more ]
Inflammation of the tongue
Smooth swollen tongue[ more ]
Increased palatal height[ more ]
High urine homocystine levels
Elevated blood homocystine
Difficulties in coordination
Incoordination of limb movements
Limb incoordination[ more ]
Onset in first year of life
Onset in infancy[ more ]
Low set ears
Lowset ears[ more ]
Underdeveloped ears[ more ]
Low blood neutrophil count
Low neutrophil count[ more ]
Low blood cell count
Low platelet count
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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.
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.
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 have a cousin in China, who sadly lost his 5-month second daughter about a week ago, who died of "combined methylmalonic aciduria and homocystinuria". My cousin is very concerned about his older daughter, who is now 3.5 years old and healthy, because he has heard that this type of genetic disease could be "late-onset". Could you help me find latest info of research and treatment on this disease, especially on screening, diagnosis and treatment of "late-onset" "combined methylmalonic aciduria and homocystinuria". Any help is much appreciated! Thank you for your time. See answer