Globalseo is still translating this page... (closing in 5s)
Skip to main content

3-methylcrotonyl-CoA carboxylase deficiency

3-methylcrotonyl-CoA carboxylase deficiency (also called MCC deficiency) is an inherited disorder in which the body is unable to process certain proteins. People with this disorder have a shortage of an enzyme that helps break down proteins that contain a particular building block (amino acid) called leucine.

Description

3-methylcrotonyl-CoA carboxylase deficiency (also called MCC deficiency) is an inherited disorder in which the body is unable to process certain proteins. People with this disorder have a shortage of an enzyme that helps break down proteins that contain a particular building block (amino acid) called leucine.

The signs and symptoms of MCC deficiency can vary among individuals, even among individuals in the same family. Some people with the genetic changes that cause MCC deficiency will not develop symptoms until adulthood, while many will never develop signs or symptoms.

Some affected individuals develop signs and symptoms in infancy or early childhood after an event such as an infection, a long period without food, or the introduction of a high-protein diet. Features of MCC deficiency may include feeding difficulties, delayed development, vomiting, excessive tiredness (lethargy), and weak muscle tone (hypotonia). If untreated, MCC deficiency can lead to seizures; breathing difficulties; and comas, which can be life-threatening.

Inheritance patterns

The source lists the following possible inheritance patterns: Autosomal recessive. More than one pattern can apply in different cases.

Other names

3-MCC deficiency

3-methylcrotonylglycinuria

BMCC deficiency

Deficiency of methylcrotonoyl-CoA carboxylase

MCC deficiency

MCCD

Methylcrotonyl-CoA carboxylase deficiency

Methylcrotonyl-coenzyme A carboxylase deficiency

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.
  • 1 Apr 2024 | Latest version
  • 1 Mar 2024 | Originally published

Join the conversation

Share your thoughts or experiences with others in our patient communities.

Disclaimer: The views expressed in the community do not represent medical advice. For any health concerns, consult your GP or healthcare provider.
flu eligibility checker

Ask, share, connect.

Browse discussions, ask questions, and share experiences across hundreds of health topics.

Sign up to the Patient newsletter

Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.