Isobutyryl-CoA dehydrogenase deficiency

Disorder Category

An organic acidemia



elevated C4 (butyrylcarnitine)

Tested By

tandem mass spectrometry (MS/MS); sensitivity=NA; specificity=NA


Isobutyryl-CoA dehydrogenase deficiency


Isobutyrylglycinuria (IBG)

Acyl-CoA dehydrogenase family, member 8


270.3, Disturbances of branched-chain amino-acid metabolism


Deficiency of Isobutyryl-CoA dehydrogenase causes inability to break down the amino acid valine in protein and resulting accumulation of organic acids. The disorder is very rare and the long term consequences of this condition are unclear.


fewer than 5 cases have been identified. [Isobutyryl-CoA Dehydrogenase Deficiency - Information for Professionals (STAR-G)]


autosomal recessive

Prenatal Testing

DNA testing or enzyme analysis by amniocentesis or CVS.

Clinical Characteristics

With treatment, improvement in growth and normal development can be expected. Without treatment, outcomes are unknown because of the very few observed cases. Symptoms were reported to start at one year of age and may be triggered by fasting and illness. Most patients identified by newborn screening have remained asymptomatic.

Treatment consists in canitine supplementation to prevent deficiency.

Follow-up Testing after Positive Screen

Quantitative plasma acylcarnitine profile, urine organic acids, urine acylglycines.

Primary Care Management

Upon Notification of the + Screen

If the Diagnosis is Confirmed

  • Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill(see Isobutyryl-CoA Dehydrogenase Deficiency - Information for Parents (STAR-G) for additional information);
  • assist in implementing and maintaining a protein restricted diet;
  • oral L-carnitine may be indicated;
  • for those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.

Specialty Care Collaboration

Initial consultation and ongoing collaboration, particularly for dietary management. Genetic counseling for the family.


Information & Support

For Professionals

Isobutyryl-CoA Dehydrogenase Deficiency - Information for Professionals (STAR-G)
Structured list of information about the condition and links to more information; Screening, Technology, and Research in Genetics.

ACT Sheet for Elevated C4 Acylcarnitine (ACMG) (PDF Document 349 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical Genetics.

Confirmatory Algorithm for Elevated C4 Acylcarnitine (ACMG)
Resource for clinicians to help confirm diagnosis; American College of Medical Genetics.

Isobutyryl-CoA Dehydrogenase Deficiency (OMIM)
Extensive review of literature that provides technical information on genetic disorders; Online Mendelian Inheritance in Man site, hosted by Johns Hopkins University.

Genetics in Primary Care Institute (AAP)
The goal of this site is to increase collaboration in the care of children with known or suspected genetic disorders. Includes health supervision guidelines and other useful resources; a collaboration among the Health Resources & Services Administration, the Maternal and Child Health Bureau, and the American Academy of Pediatrics.

For Parents and Patients

Isobutyryl-CoA Dehydrogenase Deficiency (Genetics Home Reference)
Excellent, detailed review of condition for patients and families; sponsored by the U.S. National Library of Medicine.

Isobutyryl-CoA Dehydrogenase Deficiency - Information for Parents (STAR-G)
A fact sheet, written by a genetic counselor and reviewed by metabolic and genetic specialists, for families who have received an initial diagnosis of this newborn disorder; Screening, Technology and Research in Genetics.

Baby's First Test: Isobutyryl-CoA Dehydrogenase Deficiency
Information about early signs, follow-up testing, treatment, causes, accessing care, and expected outcomes. Provides links to support services; supported by the U.S. Department of Health and Human Services.

Organic Acidemia Association (OAA)
A nonprofit organization that provides information, newsletters, calendars of events, connections with other parents, a listserv, a discussion board, and nutrition and recipe ideas.

National Newborn Screening and Global Resource Center (NNSGRC)
Provides information about each state's newborn screening programs; sponsored by the University of Texas Health Science Center at San Antonio, Department of Pediatrics.


Genetics-related clinical services throughout the world can be found through Genetics Clinic Directory (GeneTests).

Newborn Screening Programs

See all Newborn Screening Programs services providers (3) in our database.

Pediatric Genetics

See all Pediatric Genetics services providers (5) in our database.

For other services related to this condition, browse our Services categories or search our database.

Helpful Articles

PubMed search for isobutyryl-CoA dehydrogenase deficiency.

Pasquali M, Monsen G, Richardson L, Alston M, Longo N.
Biochemical findings in common inborn errors of metabolism.
Am J Med Genet C Semin Med Genet. 2006;142C(2):64-76. PubMed abstract


Author: Nicola Longo, MD, PhD - 3/2011
Content Last Updated: 4/2011