[Elevated C14:1 +/- other long-chain acylcarnitines]
Very Long-Chain Acyl-CoA Dehydrogenase Deficiency (VLCAD)
Differential Diagnosis: Very Long-Chain acyl-CoA dehydrogenase (VLCAD) deficiency.
Condition Description: VLCAD deficiency is a fatty acid oxidation (FAO) disorder. FAO occurs during prolonged fasting and/or periods of increased energy demands (fever, stress) when energy production relies increasingly on fat metabolism. In an FAO disorder, fatty acids and potentially toxic derivatives accumulate because of a deficiency in one of the mitochondrial FAO enzymes.
MEDICAL EMERGENCY - TAKE THE FOLLOWING IMMEDIATE ACTIONS:
- Contact family to inform them of the newborn screening result and ascertain clinical status (poor feeding, vomiting, lethargy)
- Consult with pediatric metabolic specialist
- Evaluate the newborn (hepatomegaly, poor feeding, lethargy, hypotonia, arrhythmia, evidence of cardiac decompensation). If signs are present or if infant is ill, initiate emergency treatment with IV glucose and oxygen. Transport to hospital for further treatment in consultation with metabolic specialist. If infant is normal initiate timely confirmatory/diagnostic testing, as recommended by specialist
- Educate family about need for infant to avoid fasting. Even if mildly ill, immediate treatment with IV glucose is needed
- Report findings to state newborn screening program (Carleigh Soule at 307-777-6297)
Diagnostic Evaluation: Plasma acylcarnitine analysis will show increased C14:1 acylcarnitine (and lesser elevations of other long chain acylcarnitines). Diagnosis is confirmed in consultation with the metabolic specialist by mutation analysis of the VLCAD gene and additional biochemical genetic tests.
Clinical Expectations: VCLAD deficiency may present in acutely in the neonate and is associated with high mortality unless treated promptly; milder variants exist. Features of severe VLCAD deficiency in infancy include hypoglycemia, hepatomegaly, failure to thrive, cardiomyopathy and arrhythmias, lethargy, and hypoketotic. Treatment is available.
Additional Information: (Click on the name to take you to the website)
Genetic Home Reference Wyoming Department of Health
Gene Tests Colorado Newborn Screening
New England Consortium American Academy of Pediatrics
For Algorithm: http://www.acmg.net/resources/policies/ACT/Visio-C14-1_(4-19-06).pdf