Short-chain acyl-CoA deficiency (SCADD)

Disorder Category

a fatty acid oxidation disorder

Screening

Finding

elevated C4 (butyrylcarnitine)

Tested By

tandem mass spectrometry (MS/MS); sensitivity=100%; specificity=99.99% [Schulze: 2003]

Names

Short-chain acyl-CoA deficiency (SCADD)

Short chain acyl-CoA dehydrogenase deficiency

SCAD

Acyl-CoA dehydrogenase short chain (ACADS)

ICD-9

277.85, Disorders of fatty acid oxidation

Overview

During prolonged fasting and/or periods of increased energy demands (fever, stress, vomiting, diarrhea), energy production relies increasingly on fat metabolism. Because SCAD deficiency (the result of an intramitochondrial defect in the beta-oxidation of fatty acids) may impair this form of energy production, metabolic crisis may result. However, for reasons that are not yet understood, most chlidren with SCADD never have symptoms and are usually healthy.

Prevalence

1/83,300 [Schulze: 2003]

Inheritance

autosomal recessive

Maternal and Family History

SCADD may be associated with maternal acute fatty liver of pregnancy and HELLP syndrome.

Prenatal Testing

DNA testing or enzyme analysis by amniocentesis or CVS.

Clinical Characteristics

The impact of treatment is unknown. Most patients identified by newborn screening will be asymptomatic, however without treatment affected infants may present with:
  • vomiting
  • lethargy
  • seizures
  • hypoketotic hypoglycemia

Subsequent symptoms may occur including:
  • failure to thrive
  • muscle weakness
  • developmental delay,
  • seizures
  • metabolic acidosis

An adult form of SCADD affects only the muscles and may cause:
  • pain and weakness, especially after exertion
  • episodes of nausea, vomiting, and shortness of breath

Milder variants of this condition are very frequent in the general population and usually do not require treatment. Even severe forms usually cause no symptoms even though they might aggravate co-existing conditions.

Treatment consists of carnitine supplementation, low-fat diet and fasting avoidance. Again, this is rarely needed.

Follow-up on positive screening test

Quantitative plasma acylcarnitine profile, urine organic acids (increased ethylmalonic acid), enzyme assay in fibroblasts; DNA analysis for common SCAD mutations. SCAD deficiency must be differentiated from other causes of elevated C4 such as ethylmalonic encephalopathy that is a much more serious condition.

Primary care management

Upon notification of the + screen

  • Contact the family and evaluate the infant for poor feeding, vomiting, lethargy
  • Provide emergency treatment/referral for signs or symptoms of hypoglycemia, lethargy, metabolic acidosis (see for additional information)
  • To confirm the diagnosis, work with the following service(s): see all Newborn Screening Programs services providers (1) in our database
  • For evaluation and ongoing collaborative management, consult the following service(s): Pediatric Medical Genetics , (801-213-3599); 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 Short-Chain Acyl-CoA Deficiency Info for Parents (STAR-G) for additional information)
  • Support the implementation of frequent, low fat, high carbohydrate meals
  • Oral L-carnitine and riboflavin may be indicated for some children

Specialty Care Collaboration

Initial consultation and ongoing collaboration with the following service(s): Pediatric Medical Genetics , (801-213-3599); See also Services below. A dietician may work with the family to devise an optimal approach to dietary management.

Resources

Information & Support

For Professionals

Short-Chain Acyl-CoA deficiency Info 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.

Newborn Screening ACT Sheets & Confirmatory Algorithms (ACMG)
ACTion (ACT) Sheets and algorithms for responding to positive newborn screening test results, membership required; American College of Medical Genetics.

Short-Chain Acyl-CoA Deficiency Acute Illness Protocol (NECMP)
A guideline for healthcare professionals treating the sick infant/child who has previously been diagnosed with SCADD, a fatty acid oxidation disorder (FAOD); developed under the direction of Dr. Harvey Levy, Senior Associate in Medicine/Genetics at Children’s Hospital Boston, and Professor of Pediatrics at Harvard Medical School, for the New England Consortium of Metabolic Programs.

Resources for SCADD (NLM)
Comprehensive compilation of links to information, articles, research, case studies, genetics, and more; from the National Library of Medicine and the Genetic Alliance.

Short-Chain Acyl-CoA Deficiency (OMIM)
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.

Utah Newborn Screening Program (UDOH)
Provides information and statistics about the program and related legislation, training for practices, and the conditions screened for; Utah Department of Health.

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 and management guidelines, and other useful resources; a collaboration among the Health Resources & Services Administration, the Maternal & Child Health Bureau, and the American Academy of Pediatrics.

For Parents and Patients

Short-Chain Acyl-CoA Deficiency Info 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.

Fatty Oxidation Disorders (FOD) Family Support Group
Information for families about fatty acid oxidation disorders, support groups, coping, finances, and links to other sites.

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.

Services

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 (1) in our database.

Pediatric Genetics

See all Pediatric Genetics services providers (4) in our database.

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

Helpful Articles

PubMed search for articles on short-chain acyl-CoA dehydrogenase deficiency (SCADD) in the last 5 years.

Viscomi C, Burlina AB, Dweikat I, Savoiardo M, Lamperti C, Hildebrandt T, Tiranti V, Zeviani M.
Combined treatment with oral metronidazole and N-acetylcysteine is effective in ethylmalonic encephalopathy.
Nat Med. 2010;16(8):869-71. PubMed abstract / Full Text
Dual treatment of oral metronidazole and N-acetylcysteine caused marked clinical improvement in five affected children, with hardly any adverse or side effects.

Authors

Author: Nicola Longo, MD, PhD - 7/2011
Compiled and edited by: Alfred Romeo, RN, PhD - 3/2007
Content Last Updated: 3/2008

Page Bibliography

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