Skip to content
Buy BioDecode
Genetics Library / Conditions / Combined malonic and methylmalonic aciduria

CONDITION REFERENCE

Combined malonic and methylmalonic aciduria

Information from MedlinePlus Genetics about this condition and how it can be inherited.

About this condition

Combined malonic and methylmalonic aciduria (CMAMMA) is a condition characterized by high levels of certain chemicals, known as malonic acid and methylmalonic acid, in the body. A distinguishing feature of this condition is higher levels of methylmalonic acid than malonic acid in the urine, although both are elevated.

The signs and symptoms of CMAMMA can begin in childhood. In some children, the buildup of acids causes the blood to become too acidic (ketoacidosis), which can damage the body's tissues and organs. Other signs and symptoms may include involuntary muscle tensing (dystonia), weak muscle tone (hypotonia), developmental delay, an inability to grow and gain weight at the expected rate (failure to thrive), low blood glucose (hypoglycemia), and coma. Some affected children have an unusually small head size (microcephaly).

Other people with CMAMMA do not develop signs and symptoms until adulthood. These individuals usually have neurological problems, such as seizures, loss of memory, a decline in thinking ability, or psychiatric diseases.

Source: MedlinePlus, National Library of Medicine. Source publication: 2023-07-26. Source review: 2013-01.

Inheritance

  • Autosomal recessive

A condition can have several forms with different inheritance patterns. Each pattern may apply to a different gene or form of the condition.

Related genes

MedlinePlus lists these genes for this condition. Open a gene page to read any available ClinGen reviews and ClinVar records.

YOUR DNA FILE

What can your DNA file tell you?

Your DNA file only includes the positions your test checked and reported. Consumer DNA kits usually test selected positions. Sequencing files can also leave out positions that were not reported or where the test could not give a result.

A variant missing from your file does not mean you tested negative for it. A ClinVar classification applies to a particular variant and the condition or finding it was reported for. It does not apply to everyone with that gene. An uncertain finding cannot establish a diagnosis.

BioDecode reads supported DNA files on your computer. It cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-09-18.

MedlinePlus Source details

Open source record ↗

Source release: Fri, 18 Sep 2026 05:17:13 GMT
Source publication: 2023-07-26
Source review: 2013-01

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

About the library sources · Latest validated release · Record 7ea5119798d5