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Very Long Chain Acyl CoA Dehydrogenase Deficiency (VLCAD)

At a glance

Approximate incidence in Ontario: Marker measured: Screening can prevent: Treatment:
Unknown, very rare C14:1 Developmental delay, failure to thrive, hepatomegaly, cardiomyopathy, coma, sudden death Avoid fasting, special diet

  • In Ontario, a heel prick is used to take a few drops of blood from each baby shortly after birth. The blood is tested for more than 25 treatable diseases, including VLCAD.
  • screen positive result means that more tests are needed to know whether or not a baby has VLCAD. It does not mean that a baby has VLCAD. Babies identified at a young age through screening can be treated early to help prevent health problems.

Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD) is a rare, inherited (genetic) disease.

  • Babies with VLCAD cannot make certain fats into energy, especially during long periods without food (fasting).
  • Babies can get very sick if they cannot make fats into energy when needed.

Without treatment, minor illnesses and fasting can cause life-threatening episodes called metabolic crises.

  • It is normal for parents and guardians to feel worried when their baby has a screen positive result. A ‘screen positive’ result does not mean that a baby has VLCAD. It means that there is a chance that the baby may have VLCAD.
  • Follow-up testing is important to find out whether the baby truly has VLCADD.
  • The baby’s health care provider or a health care provider at a newborn screening regional treatment centre will discuss the results with the baby’s family.
  • Follow-up testing is arranged as soon as possible and involves blood and urine tests. Sometimes a small skin sample is needed.
  • It can take a few days to weeks to find out if a baby truly has VLCAD or not. This waiting period can be hard for families.

  • Normal – the baby does not have VLCAD.
  • Abnormal – the baby does have VLCAD and will need treatment. The family will be supported by a team of caring specialists.
  • Inconclusive – more testing is required. The baby will be followed closely by a specialist to ensure that he/she receives optimal care.

Most babies with VLCAD appear normal at birth but they are at risk of a serious health condition called a metabolic crisis. A metabolic crisis is a life-threatening episode caused by low blood sugar and/or the build-up of harmful substances in the blood.

Symptoms of a VLCAD metabolic crisis include:

  • poor feeding
  • vomiting
  • excessive sleepiness
  • irritability
  • muscle spasms
  • enlarged liver

If a metabolic crisis is not treated, breathing problems, seizures, coma, brain damage and sometimes death can occur. Between episodes of metabolic crisis, babies with VLCAD may not show any signs of the disease. Other babies with VLCAD may have problems with their heart, liver and muscles.

Screening and treatment aim to prevent metabolic crises and other symptoms and help children with VLCAD to lead the healthiest lives possible.

Treatment is started as early as possible and is usually life long. Babies with VLCAD have their health and development checked regularly and are followed by a team, including a metabolic doctor and a dietitian.

Treatment may include:

  • Frequent feeding, especially when ill
    • To prevent a metabolic crisis, babies with VLCAD must not go a long time without eating.
  • Aggressive treatment of illnesses
    • Children with VLCADD may need to go to the hospital for minor illnesses like a cold or flu, and any time they stop eating.
  • A diet low in certain fats may be recommended.
  • Supplements such as carnitine and corn starch as well as medications may be prescribed.
  • If signs of a metabolic crisis (above) are present, urgent medical care must be found.

  • With early treatment and careful monitoring babies with VLCAD can often lead healthy lives with normal growth and intelligence.
  • As children get older, the risk of metabolic crisis decreases.
  • Before early detection by newborn screening, this disease was often fatal.

If your baby has screened positive for VLCAD deficiency, click here for more information.

Contact Us

Children’s Hospital of Eastern Ontario
415 Smyth Road
Ottawa, Ontario K1H 8M8

Toll-Free: 1-877-627-8330
Local: (613) 738-3222
Fax: (613) 738-0853

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