MCADD
Screening
Finding
Elevated C8 (octanoylcarnitine) with lesser elevations of C6 (hexanoylglycine) and C10:1 (decenoyl carnitine)Tested By
Tandem mass spectrometry (MS/MS); sensitivity=100%; specificity=99.98% [Schulze: 2003]Overview
Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is one of several enzymes involved in the beta-oxidation of fatty acids within mitochondria. MCADD impairs hepatic ketogenesis, resulting in hypoketotic hypoglycemia during periods of prolonged fasting or increased energy demands (e.g., during acute illness or fever).Incidence
Prevalence is about 1:17,759 live births; it is most common in northern Europeans and US Caucasians. [Therrell: 2014]Clinical Characteristics
With treatment, prognosis is excellent. Without treatment, episodes of hypoketotic hypoglycemic accompanied by lethargy and vomiting may lead to seizures, coma, cardiac arrest, and death. Symptoms can appear shortly after birth (sometimes just after hospital discharge) or at time of acute illness, which prevents the child from eating or causes increasing energy expenditure (fever). Some affected individuals do not present until adulthood.Initial symptoms/signs may include:
- Poor feeding
- Vomiting
- Lethargy progressing to coma
- Lab findings:
- Hyperammonemia
- Hypoglycemia
- Elevated ALT and AST
- Hepatomegaly
- Liver dysfunction
- Seizures
- Encephalopathy
- Sudden death
Follow-up Testing after Positive Screen
Quantitative plasma acylcarnitine profile, urine acylglycine (increased hexanoylglycine), urine organic acids - diagnosis is confirmed by DNA analysisPrimary Care Management
Upon Notification of the + Screen
- Contact the family and evaluate the infant for related symptoms.
- Provide emergency treatment and referral for symptoms of hypoglycemia, lethargy, and feeding problems.
- Make sure the child eats at regular intervals (every 3 to 4 hours) and formula is available to the family in case breastfeeding becomes insufficient.
- Confirm the diagnosis, work with the following service(s): see all Newborn Screening Programs services providers (22) in our database.
- Evaluate and continue ongoing collaborative management, consult the following service(s): see all Pediatric Genetics services providers (3) in our database.
If the Diagnosis is Confirmed
- Educate the family about signs, symptoms, the need for frequent feedings, and the need for urgent care if the infant becomes ill. (See MCADD - Information for Parents (STAR-G) for additional information.)
- Provide an "emergency" letter guiding caregivers in the appropriate response to acute illness and a medical ID bracelet for older kids and adults.
- Consider a heart-healthy diet for affected children after 1 year of age.
- Consider oral L-carnitine, which may be recommended in case of deficiency.
- Assist in management of irreversible consequences as necessary, particularly with developmental and educational interventions.
- See the Portal’s diagnosis and management module for MCADD.
Specialty Care Collaboration
A dietician may work with the family to devise an optimal approach to dietary management.Resources
Information & Support
For Professionals
MCADD (GeneReviews)
Excellent review of MCADD that includes a clinical description, differential diagnoses, management information, and molecular
genetic information; by Detrich Matern, MD and Piero Rinaldo, MD, PhD - sponsored by the U.S. National Library of Medicine.
For Parents and Patients
MCADD - 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.
MCADD (Genetics Home Reference)
Excellent, detailed review of MCADD for patients and families; sponsored by the U.S. National Library of Medicine.
Fatty Oxidation Disorders (FOD) Family Support Group
Information for families about fatty acid oxidation disorders, support groups, coping, finances, and links to other sites.
National Newborn Screening & Global Resource Center (NNSGRC)
Fact sheets, data reports, publications, and information for clinicians about genetic screening that includes links to state
genetic contacts.
Tools
ACT Sheet for MCAD (ACMG) (
348 KB)
Contains short-term recommendations for clinical follow-up of the newborn who has screened positive; American College of Medical
Genetics.
Confirmatory Algorithm for MCADD (ACMG) ( 63 KB)
Resource for clinicians to help confirm diagnosis; American College of Medical Genetics.
MCADD Acute Illness Protocol (NECMP) ( 17 KB)
Guideline for clinicians treating the sick infant or child who has MCADD; 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. Click pdf to view the complete protocol.
Services in Idaho
Newborn Screening Programs
See all Newborn Screening Programs services providers (22) in our database.
For other services related to this condition, browse our Services categories or search our database.
Helpful Articles
PubMed search for MCADD in children, last 3 years.
Leonard JV, Dezateux C.
Newborn screening for medium chain acyl CoA dehydrogenase deficiency.
Arch Dis Child.
2009;94(3):235-8.
PubMed abstract
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
Therrell BL Jr, Lloyd-Puryear MA, Camp KM, Mann MY.
Inborn errors of metabolism identified via newborn screening: Ten-year incidence data and costs of nutritional interventions
for research agenda planning.
Mol Genet Metab.
2014;113(1-2):14-26.
PubMed abstract / Full Text