Carnitine Uptake Defect (CUD)

• 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 carnitine uptake defect (CUD). 
• A screen positive result means that more tests are needed to know whether or not a baby has CUD. It does not mean that a baby has CUD. Babies identified at a young age through screening can be treated early to help prevent health problems. 

• CUD is a rare, inherited (genetic) disease. 

  • Babies with CUD have trouble absorbing a protein called carnitine into their cells. 
  • The cells need carnitine to make certain types of fat into energy. 
  • Fats are an important source of energy for the muscles, brain, and heart, especially between meals. 

• 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 CUD. It means that there is a chance that the baby may have CUD. 
• Follow-up testing is important to find out whether the baby truly has CUD. 
• 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 blood and urine tests will be arranged as soon as possible. Testing may also be done for the baby’s mother. 
• It can take a few days to weeks to find out if a baby truly has CUD or not. This waiting period can be hard for families. 

• Normal – the baby does not have CUD. 
• Abnormal – the baby does have CUD 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. 

Without treatment, symptoms can range from absent to severe. 

While most babies with CUD are normal at birth, early signs of the disease can include: 

• Poor growth 
• Excessive tiredness 
• Failure to feed properly 
• Sweating while feeding (due to heart failure) 
• Muscle weakness (may not happen in the newborn and early period) 
• Large liver 

Early treatment helps to prevent serious and life-threatening health problems such as: 

• Heart failure 
• Metabolic crisis - a serious health condition caused by low blood sugar and/or the build-up of harmful substances in the blood. If a metabolic crisis is not treated, breathing problems, seizures, coma, brain damage and sometimes death can occur. 

Symptoms of a metabolic crisis are: 

• Poor feeding 
• Vomiting 
• Lethargy 
• Excessive sleepiness 
• Irritability 

Screening and treatment aim to prevent metabolic crises and help children with CUD lead healthy lives. 

• CUD is easily treated. Treatment involves: 

  • Medication (large doses of carnitine) 
  • Babies with CUD should not go for long periods of time without eating. 
  • A diet low in certain fats is sometimes recommended. 
  • Treatment begins as early as possible and is life long. 
  • A team, including a metabolic doctor and a dietitian, cares for babies with CUD. 
  • Babies with CUD have their health and development checked regularly. 
  • Regular follow-up tests are used to monitor and adjust treatments. 

• With early detection and careful treatment, children with CUD are usually as healthy and intelligent as other children their age.