Health Encyclopedia

Methylmalonic acidemia

Definition

Methylmalonic acidemia is a disorder, passed down through families, in which the body cannot break down certain proteins and fats. The result is a build up of a substance called methylmalonic acid in the blood.

It is considered an inborn error of metabolism.

Causes, incidence, and risk factors

The disease is usually diagnosed in the first year of life. It is an autosomal recessive disorder, which means the defective gene must be passed onto the child from both parents.

About 1 in 25,000 - 48,000 babies are born with this condition. However, the actual rate may be higher, because a newborn may die before the condition is ever diagnosed. Methylmalonic acidemia affects boys and girls equally.

Symptoms

The disease can cause seizures and stroke. Babies may appear normal at birth, but develop symptoms once they start eating more protein, which can cause the condition to get worse.

Symptoms include:

Brain disease that gets worse (progressive encephalopathy)
Dehydration
Developmental delays
Failure to thrive
Lethargy
Repeated yeast infections
Seizures
Vomiting

Signs and tests

Testing for methylmalonic acidemia is often done as part of a newborn screening exam. The U.S. Department of Health and Human Services recommends screening for this condition at birth because early detection and treatment has been shown to be beneficial.

Tests that may be done to diagnose this condition include:

Treatment

Treatment consists of cobalamin and carnitine supplements and a low-protein diet. The child's diet must be carefully controlled.

If supplements do not help, the doctor may also recommend a diet that avoids substances called isoleucine, threonine, methionine, and valine.

Liver or kidney tranplantation (or both) have been shown to help some patients. These transplants provide the body with new cells that help breakdown methylmalonic acid normally.

Expectations (prognosis)

Patient may not survive their first attack.

Complications

Coma
Death
Kidney failure

Calling your health care provider

Seek immediate medical help if a child is having a seizure for the first time. See a pediatrician if your child has signs of failure-to-thrive or developmental delays.

Prevention

A low-protein maintenance diet can help to reduce the number of acidemia attacks. Persons with this condition should avoid those who are sick.

Genetic counseling may be helpful for couples with a family history of this disorder who wish to have a baby.

References

Arn PH. Newborn screening: current status. Health Affairs. 2007;26:559-566.

Nagarajan S, Enns GM, Millan TM, Winter S, Sarwal MM. Management of methylmalonic acidaemia by combined liver-kidney transplantation. J Inherit Metab Dis. 2005; 28(4):517-24.

Review Date:4/26/2007
Reviewed By:Robert Hurd, MD, Professor of Endocrinology, Department of Biology, Xavier University, Cincinnati, OH. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.