Symptoms

Signs and symptoms of MCAD deficiency typically first appear in babies and young children. In rare cases, the disorder is not diagnosed until adulthood.

Signs and symptoms can vary among people with MCAD deficiency, but they typically include:

• Vomiting
• Lack of energy
• Low blood sugar (hypoglycemia)

Hypoglycemia can be triggered by:

• Going too long without eating or by fasting
• Not eating enough complex carbohydrates
• Viral infections and other illnesses
• Recurrent fever
• Vomiting
• Diarrhea
• Increased exercise
• Vaccinations
• Significant stress

Sometimes episodes of hypoglycemia can occur with no symptoms in between these episodes.

When to see a doctor

In the U.S., all newborn screening programs now test for MCAD deficiency. If you notice signs and symptoms of MCAD deficiency or if you have concerns about your child's health, contact your doctor. After the initial evaluation, you may be referred to a doctor trained in evaluating and treating MCAD deficiency and other health care team members such as a dietitian.