Long Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency (LCHAD)

Babies with the diseases long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) or trifunctional protein deficiency (TFP) are identified through newborn screening because they have an elevated C160H level.

Because babies with an elevated C160H level screen positive for both LCHAD and TFP, information about both diseases is contained together on this page.

• 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 LCHAD and TFP.
• A screen positive result means that more tests are needed to know whether or not a baby has one of these diseases. It does not mean that a baby has a disease. Babies identified at a young age through screening can be treated early to help prevent health problems.

LCHAD and TFP are rare, inherited (genetic) diseases.

• Babies with LCHAD and TFP 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.

• 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 LCHAD or TFP. It means that there is a chance that the baby may have LCHAD or TFP.
• Follow-up testing is important to find out whether the baby truly has LCHAD or TFP.
• 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 LCHAD or TFP or not. This waiting period can be hard for families.

• Normal – the baby does not have LCHAD or TFP.
• Abnormal – the baby does have LCHAD or TFP 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 LCHAD and TFP are 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 LCHAD or TFP 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 LCHAD and TFP may not show any signs of the disease. Other babies with LCHAD or TFP may have problems with their heart, liver and muscles.

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

Treatment for LCHAD and TFP is started as early as possible and is usually life long.

Treatment may include:

• Frequent feeding, especially when ill
  • To prevent a metabolic crisis, babies with LCHAD and TFP must not go a long time without eating.
• Aggressive treatment of illnesses
  • Children with LCHAD and TFP 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.

A team, including a metabolic doctor and a dietitian, cares for babies with LCHAD and TFP. Babies with LCHADD and TFP have their health and development checked regularly. If signs of a metabolic crisis (above) are present, urgent medical care must be found.

• With early treatment and careful monitoring babies with LCHAD and TFP 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.