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Clinical and Basic Investigations of Methylmalonic Acidemia (MMA) and Related Disorders

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Frequently Asked Questions About Methylmalonic Acidemia (MMA)

What is this study about?

This study will evaluate patients with methylmalonic acidemia (MMA) to learn more about the genetic causes of the various types of this inherited metabolic disorder and the medical complications associated with it. People with MMA may have problems with learning and development and kidney malfunctioning. They can become seriously ill, sometimes with little warning. There is no cure for any MMA, but special diets and vitamin therapies are used for treatment.

Why should I join the study?

People join research studies for many reasons. Three common reasons include:

1. Altruism. This simply means "a regard for others." For example, why do many people donate blood? Most of the time, the blood helps a stranger in need, and not anyone known to the donator. For many people, it feels good to help others, and that is reason enough. The same is true for a research study. There may be no direct benefit to you, but by helping doctors learn about MMA, you are helping the wider community with MMA.
   
   
2. Learning. It is not unusual for a person with a rare disease (like MMA) to know more about their illness than their doctors! Joining a research study is a chance to spend time with doctors with a special interest in MMA. There is a lot of time to ask questions, to learn "what's new" and to better understand MMA.
   
   
3. Advice. People join research studies to seek medical advice from doctors with special expertise and interest in their disease. This can range from confirmation of a diagnosis to guidance on a new problem. It is important to remember that doctors involved in research (such as those at NIH) work with, but cannot replace, your "regular doctor". However, we may be able to find doctors, and other medical professionals and support groups in your local area with experience with MMA

New information, treatments and in the future, a cure, for methylmalonic acidemia will only come from people with MMAworking together with doctors. Animal models of the disease (like mice) are helpful up to a point. But there is no replacement for studying the disease in a human being.

What we are trying to learn with the study?

What are we NOT trying to do?

1. We are NOT testing any new medication or procedure to treat or cure MMA.
2. At the National Institutes of Health (NIH), we are interested in research. Although we are happy to provide advice for people enrolled in our study, we are not able to "take over" the long-term care of a person with MMA
3. To enroll in our study, a person needs a diagnosis of MMA. We are not able to provide "first time" diagnosis or second opinions.

Who is eligible to participate?

To be in our study, a person must:

1. Be between between 2 and 70 years of age.
2. Be able to travel to and be admitted to the NIH Clinical Center for 4 to 5 days for 5 to10 years.
3. Positive diagnosis based on homocysteine levels in plasma an urine. Some patients who have not yet had these laboratory tests will be admitted to the protocol based upon metabolic parameters and clinical history.
4. Be willing and able to come to the NIH in Bethesda, Maryland.

There are some reasons that may prevent you from joining the study. Patients will be excluded if they cannot travel to the NIH because of their medical condition or are less than 2 years of age. The PI may decline to enroll a patient for other reasons. Other criteria that may lead to exclusion include: residing in a hospital; sub-optimal metabolic control as determined by Dr. Venditti's review of the laboratory data; any patient who requires dialysis once or more/week and weighs less than 40 kg; any patient who is being treated for an intercurrent infection with antibiotics or has evidence of an acute infection; and any patient who does not have a regular/local metabolic, genetic or endocrine physician and/or a family physician, pediatrician or internist.

What is involved in the study?

In this study, we will clinically evaluate patients with methymalonic acidemia and cobalamin (vitamin B) metabolic defects. We will define and characterize a patient population, obtain cells and urine, perform mutation analysis in known genes, and search for the causative genes when the molecular basis of the complementation class is uncertain.

Routine inpatient admissions will last 4 to 5 days and occur every year. They will involve urine collection, blood drawing, ophthalmologic examination, radiological procedures, skin biopsies and developmental testing. In a subset of patients who have or will receive renal, hepato- or hepato-renal transplants or have an unusual variant or clinical course and have MMA, a lumbar puncture to examine CSF metabolites will be performed. In this small group of patients, CSF metabolite monitoring may be used to adjust MMA therapy.

What about my privacy?

[Need MMA relevant information here if you chose to address this question]

What is the cost of the study?

The visits and all testing are free and there is no cost to you, your family or your insurance company for this study.

What about travel?

[Need MMA study info here if you wish to address this question]: We will pay your travel and parking expenses. If you live locally (near the NIH) we cover your expenses to come to NIH for two days, including some meals. If you live further away, we will pay for your transportation to NIH (plane, car, train, etc), hotel, meals and expenses. Travel must be arranged by NIH.

Will I get paid for joining the study?

[Need MMA study info here if you wish to address this question] No, participants in the study do not receive any compensation other than travel and lodging expenses. There may be no benefit to you but we hope the results from the study will benefit families with MMA.

How do I enroll?

You may contact Dr. Charles Venditti at venditti@mail.nih.gov.

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Last Reviewed: August 25, 2008