VLCAD deficiency: diagnostic test at birth, symptoms, treatments: Femme Actuelle Le MAG

VLCAD deficiency affects approximately 1 in 100,000 births, specifies the High Authority of Health. This pathology, of genetic origin, is potentially fatal. This is why the HAS wants screening for this disease to be carried out at birth. Vomiting, convulsions, hypoglycemia, cardiomyopathy are part of the symptom picture. Find out what VLCAD deficiency is, its symptoms and treatments.

1. Definition of VLCAD deficiency

To function well, the body needs energy. First, it is drawn from glucose reserves. But when your baby is fasting, the body does not have enough glucose in reserve and draws from lipids to meet its needs. However, in the event of a deficiency in VLCAD (very long chain fatty acid dehydrogenase), lipid metabolism is carried out poorly. The body, which needs these enzymes to draw energy from fatty acids at the cellular level, can no longer rely on this energy resource. The consequences can be fatal. This disease is part of a group of rare genetic diseases, grouped under the name “fatty acid oxidation deficiencies”, informs the MSD Manual.

2. Diagnostic test for VLCAD deficiency at birth to save lives

In February 2024, the High Authority of Health (HAS) recommended the addition of VLCAD deficiency to the list of diseases detected at birth. Indeed, since 1978 in France, for each newborn, a Guthrie test has been carried out by taking a drop of blood from the heel. So far, this newborn screening test covers the detection of 13 diseases, including sickle cell anemia and cystic fibrosis. The idea of ​​the HAS is to add this genetic disease to the list of these 13 pathologies to save lives. The argument is based on two observations: the disease has no characteristic symptoms, and its progression can be very rapid to the point of causing death.

3. Symptoms of VLCAD deficiency

It is difficult to recognize the symptoms of VLCAD deficiency because they are not specific. According to the National Institute of Excellence in Health and Social Services (Inesss), we sometimes observe crises from birth. During these attacks, the person is subject to vomiting, convulsions, hypoglycemia, heart rhythm disturbances associated with cardiomyopathy. These symptoms can progress very quickly and lead to cardiorespiratory arrest and death.

4. Treatments for VLCAD deficiency

There is no curative treatment for VLCAD deficiency. The care is multidisciplinary: pediatrician, nutritionist, psychologist. The main measure is to ensure that your child has sufficient carbohydrate intake for his or her needs. It is therefore advisable to avoid fasting, intense efforts, and adopt a diet rich in carbohydrates, with an additional intake of triglycerides. In the event of crises, an emergency glucose infusion is performed to restore metabolic balance.


  • Diseases of Fatty Acid Oxidation, Dr. Matt Demczko, The MSD Manual – Consumer Version, December 2021
  • Very long chain fatty acid dehydrogenase deficiency, National Institute of Excellence in Health and Social Services
  • MCAD (Acyl-CoA dehydrogenase of medium-chain fatty acids) deficiency and other deficits in mitochondrial β-oxidation of fatty acids, Haute Autorité de Santé, June 2021

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