Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

MCADD is a rare genetic condition where a person has problems breaking down fat to use as an energy source.

This means that someone with MCADD can become very ill if their body’s energy demands exceed their energy intake, such as during infections or vomiting illnesses when they’re unable to eat. Problems occur because fat is only partially broken down, which leads to a lack of energy and a build-up of harmful substances in the body. MCADD is a lifelong condition that’s present from birth. It’s estimated to affect up to 1 in every 8,000 babies born in the UK.

What are the effects of having MCADD: Babies with MCADD are at risk of developing the following symptoms:

  • poor feeding
  • drowsiness/sleepiness
  • vomiting
  • lethargy
  • seizures

These symptoms can be controlled with treatment. Left untreated, babies with MCADD can deteriorate, have fits and slip into a coma which can be life threatening.

These effects can be prevented if the disorder is identified and treated in the first few days of life which is why screening is strongly recommended.

How is MCADD treated: Babies with MCADD do not need any special medications. Day to day management is to avoid prolonged periods without eating even when well. Babies with MCADD should feed regularly and it is fine for them to be breast or bottle fed, the length of time your baby can go without eating is known as the maximum “safe fasting time” and it varies depending on age; you’ll be given advice about this.  As they grow, they should eat a normal healthy diet and be treated like any other child.

The following information leaflets are available for parents and can be downloaded from the UK newborn screening Programme website:

MCADD suspected: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/511515/MCADD_suspected_A5_version.pdf

MCADD confirmed diagnosis: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/581271/MCADD_confirmed_A5_version_040117.pdf