Newborn Screening For Amino Acid Metabolic Disorders

Inborn Errors of Metabolism

Your baby’s newborn screening may include testing for certain amino acid metabolism disorders. These rare health conditions affect a body’s metabolism. Metabolism is the way your body changes food into the energy it needs to breathe, digest food and grow. In the United States, all babies have newborn screening tests to see if they may have certain inherited conditions when they are born.

Many babies with these disorders look and seem healthy at birth. Without treatment, these conditions can lead to serious health problems and even death. With early diagnosis and treatment, most babies with these disorders can lead healthy lives. This is why newborn screening right after birth is so important. People with this condition usually need treatment for their whole life.

How is Newborn Screening Done?

Newborn screening is done during the first few days of your baby's life—usually by a health care provider in the hospital. A few drops of blood from a heel prick are placed on a special card, called a Guthrie card.

This card with your baby's information is mailed to a special state laboratory that will test the blood sample for certain health conditions, including CF. In Nevada, newborn screening involves two blood samples, first one between 24-48 hours of age and second one between 10-14 days of age.

If your baby has a positive newborn screen suggestive of an amino acid metabolism disorder, diagnostic testing is required to separate the true positives from false positives. Other contributing factors may cause a false positive result. As well, newborn screening is not diagnostic and follow-up evaluation is required. These specialized tests are sent to a reference laboratory for testing. Using one reference laboratory for all ordered tests is highly recommended due to smaller specimen volumes and shorter turn-around time for results.

Primary care providers (PCP) should consult with a pediatric metabolic specialist for information and guidance regarding specific diagnostic tests, reference lab results, clinical concerns, and clinical follow-up.

Visit the following websites for more information:


NBS Metabolic Consultant
Nicola Longo, MD, PHD
University of Utah Genetics/Pediatrics
295 Chipeta Way Salt Lake City, UT 84108
Phone: (801) 585-2457
Fax: (801) 587-7690

Shirley Farkas RDN, LD, CDE
Nevada Early Intervention Services
1161 S. Valley View Blvd. Las Vegas, NV 89102
Phone: (702) 486-9263
Fax: (702) 486-9262

Bente Riley, RDN, LD, CLC
Brenda Mortara, RDN, LD, CLC
Nevada Early Intervention Services
2667 Enterprise Rd. Reno, NV 89512
Phone: (775) 688-1341
Fax: (775) 688-2984