
			Screening & Prevention

Screening and Prevention Intro
Developmental Screening
Infant Social-Emotional Screening
Maternal Depression Screening
Newborn Screening
- Amino Acid Disorders
- Endocrine Disorders
  - Congenital adrenal hyperplasia
  - Congenital hypothyroidism
- Fatty Acid Oxidation Disorders
- Galactosemias
  - Galactosemia
- Hemoglobinopathies
  - Sickle cell disease
- Organic Acidemias

Isovaleric acidemia

Screening

Tested By

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

Names

Isovaleric acidemia

IVA

Isovaleryl-CoA dehydrogenase deficiency

IVD deficiency

ICD-9

270.3, Disturbances of branched-chain amino-acid metabolism

Lack of isovaleryl-CoA dehydrogenase, involved in the metabolism of the branched chain amino acid leucine, results in the inability to break down isovaleric acid, resulting in accumulation of potentially toxic metabolites. Clinical manifestations of the illness include an acute neonatal form and a chronic intermittent form.

Prevalence

about 1/230,000 live births [Isovaleric acidemia info for professionals, STAR-G]

Inheritance

autosomal recessive

Prenatal Testing

DNA testing or enzyme analysis by amniocentesis or CVS.

Clinical Characteristics

With early diagnosis and ongoing treatment, most affected children will have normal development. Without treatment, those with the chronic, intermittent form may suffer neurologic damage, though most are developmentally normal. Those with the acute neonatal form will present in the first few days or weeks of life and about half will die during their first episode. After the neonatal period, symptoms may be triggered by consuming too much protein and illness. Children may be healthy between metabolic crisis episodes.

Initial symptoms may include:

"sweaty feet" odor;
vomiting;
lethargy progressing to coma;
lab findings:
- ketoacidosis;
- elevated ammonia levels in the blood; and
- neutropenia, thrombocytopenia, anemia.

Follow-up on positive screening test

Quantitative plasma acylcarnitine profile, urine organic acids, urine acylglycine and acylcarnitine analysis.

Primary care management

Upon notification of the + screen

Contact the family and evaluate the infant for poor feeding, vomiting, lethargy, odor of sweaty feet;
Provide emergency treatment/referral for symptoms of poor feeding, vomiting;
Discontinue breast or cow milk formula feeding;
To confirm the diagnosis, work with the following service(s): Utah Newborn Screening Program, (801-584-8256); See also Services below;
For evaluation and ongoing collaborative management, consult the following service(s): Metabolic Clinic, (801-585-2457); See also Services below;

If the diagnosis is confirmed

Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill (see Isovaleric acidemia info for parents, STAR-G for additional information);
Low protein, low leucine, and high carbohydrate meals may be indicated for affected children;
Oral L-carnitine and glycine may be indicated for some affected children;
Bicarbonate and glucose may be indicated during metabolic crisis episodes;
For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.

Specialty Care Management

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

Resources

Links

For Professionals

Isovaleric acidemia info for professionals, STAR-G
On the Screening, Technology and Research in Genetics (STAR-G) site, one of a series of Disorder Fact Sheets for Professionals; structured list of information about the condition, with links to more information.

ACT Sheet for Isovaleric acidemia from ACMG (pdf 135kb)
Developed by the American College of Medical Genetics (ACMG), includes recommended responses to positive newborn screening test results, diagnostic evaluation, clinical expectations, and sources of additional information. See the ACMG ACT Sheets and Confirmatory Algorithms (link elsewhere on this page) for more info and sheets on other conditions.

ACMG ACT Sheets and Confirmatory Algorithms
The American College of Medical Genetics (ACMG) has developed ACTion (ACT) Sheets and algorithms for responding to positive newborn screening test results. This page contains a table with links to all of the ACT Sheets and related algorithms.

Isovaleric acidemia, OIMM
From the Online Mendelian Inheritance in Man site, hosted by Johns Hopkins University, providing technical information for providers on genetic disorders, links to MEDLINE, and links to other scientific information and sites.

Isovaleric acidemia Emergency Protocol
A protocol for management of the patient with a positive screen for Maple Syrup Urine Disease, from the New England Consortium of Metabolic Programs.

For Parents

Isovaleric acidemia info for parents, STAR-G
From the Screening, Technology and Research in Genetics (STAR-G) site, providing information for parents about isovaleric acidemia and links to other sites including parent support groups.

Isovaleric acidemia, Genetics Home Reference
Excellent, detailed review aimed at patients and families from the National Library of Medicine's Genetics Home Reference site.

Isovaleric acidemia - Guide for Parents
A detailed, 8-page booklet from the Pacific Northwest Regional Genetics Group, including specific dietary guidelines.

Organic Acidemia Association (OAA)
A non-profit organization that provides information for parents and providers; newsletters; event information; connections with other parents; a listserv; a discussion board; information about nutrition and recipes; translation of their web pages into five other languages; hosting of the Propionic Acidemia Research Network and other research funds; and links to other sites.

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

Helpful Articles

PubMed search for articles on isovaleric acidemia in the last 5 years.

Authors

Reviewing Author:

Nicola Longo MD, PhD, 3/2007

Compiled and edited by:

Alfred Romeo RN, PhD, 3/2007

Content Last Updated:

3/2008

	Note: This Web site is being reprogrammed to better serve our users. Improvements to the existing site will be limited during this time. Please use the Contact link at the top of the page to let us know about any problems or issues you find. Thanks for your patience.

	Copyright © 2001 -2008 Utah Collaborative Medical Home Project 50 N. Medical Drive, 2A200 Salt Lake City, UT 84132 Policies \| Disclaimers

Isovaleric acidemia

Disorder Category

Screening

Finding

Tested By

Names

ICD-9

Overview

Prevalence

Inheritance

Prenatal Testing

Clinical Characteristics

Follow-up on positive screening test

Primary care management

Upon notification of the + screen

If the diagnosis is confirmed

Specialty Care Management

Resources

Links

For Professionals

For Parents

Services

Newborn Screening Programs

Pediatric Genetics

Helpful Articles

Authors