Sign-in for special features         Site map | Contact | Feedback |  
   Home | About | Families | Education & Schools | Transitions | Tech Review | Resources | Screening & Prevention | Diagnoses
  Return to medhomeportal homepage.     Screening & Prevention


Screening & Prevention >> Newborn Screening >> Fatty Acid Oxidation Disorders >> CACT

CACT

Disorder Category

a fatty acid oxidation disorder

Screening

Finding

elevated C16 and/or C18:1 (acylcarnitines)

Tested By

tandem mass spectrometry (MS/MS); sensitivity=100%; specificity=99.98% [Schulze: 2003]

Names

CACT

Carnitine acylcarnitine translocase (CACT or CAT) deficiency

Carnitine acylcarnitine carrier (CAC) deficiency

Solute carrier family 25 member 20 (SLCA25A20)

ICD-9

277.85, Disorders of fatty acid oxidation

Overview

Caused by a deficiency of CACT, a mitochondrial membrane carrier protein, responsible for transport of fatty acids into mitochondria for oxidation. During prolonged fasting and/or periods of increased energy demands (fever, stress) energy production relies increasingly on fatty acid oxidation. Without CACT, long-chain acylcarnitines are unavailable for mitochondrial oxidation, production of ATP, and acetyl-CoA, and resultant energy production and gluconeogenesis. Long-chain acylcarnitines and free fatty acids can alter the electrical properties of cardiac cells resulting in arrhythmia.

Prevalence

about 1/250,000 live births [Schulze: 2003]

Inheritance

autosomal recessive

Maternal and Family History

There may be a family history of Sudden Infant Death Syndrome (SIDS). Maternal preeclampsia has been reported.

Prenatal Testing

DNA testing, enzyme testing, acylcarnitine analysis, and protein analysis by amniocentesis or CVS.

Clinical Characteristics

With treatment with medium chain triglycerides that do not require carnitine to enter the mitochondria, mild forms of the disease respond. [Iacobazzi: 2004] The disease may be fatal. Without treatment, hypoglycemic crises lead to coma and death; cardiomyopathy and cardiac arrhythmia may also be fatal. The neonatal type, with essentially no CACT and poor outcomes, is more common; the childhood type, with some residual CACT activity, is milder and usually does not have cardiac involvement.

Initial symptoms/signs may include:
  • poor feeding;
  • vomiting;
  • lethargy;
  • weakness;
  • hepatomegaly;
  • cardiac insufficiency or arrythmia;
  • lab findings;
    • hyperammonemia;
    • metabolic acidosis;
    • hypoketotic hypoglycemia; and
    • mildly elevated CK and liver enzymes.

Follow-up on positive screening test

Quantitative plasma acylcarnitine profile, urine organic acid analysis. Diagnosis is confirmed by enzyme assay in fibroblasts or DNA sequencing.

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 CACT info for parents, STAR-G for additional information);
  • Support initiation and maintenance of dietary restriction of long chain fatty acids, high carbohydrate/low-fat diet, avoidance of fasting;
  • Carnitine supplements, medium chain triglyceride (MCT) oil supplements, and cornstarch may be indicated;
  • For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.

Specialty Care Management

Initial consultation and ongoing collaboration if the child is affected. A dietician may work with the family to devise an optimal approach to dietary management.

Resources

Links

For Professionals

CACT 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 CACT from ACMG (pdf 90kb)
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.

CACT, OMIM
Extensive review of the literature, including clinical features and gene therapy, 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.

For Parents

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

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

Fatty Oxidation Disorders (FOD) Family Support Group
The FODsupport.org site offers a variety of information for families about fatty acid oxidation disorders, support groups, coping, finances, and links to other sites.

Services

Newborn Screening Programs

Utah Newborn Screening Program, more info...
44 Mario Capecchi Drive
Salt Lake City, UT84114
Phone: 801-584-8256
Fax: 801-536-0966
http://health.utah.gov/newbornscreening

Pediatric Genetics

Metabolic Clinic, more info...
100 Mario Capecchi Drive
Salt Lake City, UT84113
Phone: 801-585-2457
Fax: 585-7252
http://www.ped.med.utah.edu/divisions/divisions.htm

See all Pediatric Genetics services providers (3) in our database.

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

Helpful Articles

PubMed search for review articles on CACT 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

Page Bibliography

Iacobazzi V, Pasquali M, Singh R, Matern D, Rinaldo P, Amat di San Filippo C, Palmieri F, Longo N.
Response to therapy in carnitine/acylcarnitine translocase (CACT) deficiency due to a novel missense mutation.
Am J Med Genet A. 2004;126(2):150-5. PubMed abstract

Schulze A, Lindner M, Kohlmuller D, Olgemoller K, Mayatepek E, Hoffmann GF.
Expanded newborn screening for inborn errors of metabolism by electrospray ionization-tandem mass spectrometry: results, outcome, and implications.
Pediatrics. 2003;111(6 Pt 1):1399-406. PubMed abstract
  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. UCMHP logo     
 
  Copyright © 2001 -2008   Utah Collaborative Medical Home Project   50 N. Medical Drive, 2A200 Salt Lake City, UT 84132
Policies  |  Disclaimers