Most parents would embrace the opportunity to test their newborn for a life-threatening disease, especially if early detection meant avoiding serious health problems. Expanded newborn screening is a test that surprisingly few parents have heard about and few pediatricians use. But for approximately $25.00, your baby can be screened for 30 inherited conditions, all of which are treatable if caught early in life.
Sandy and Douglas McLaughlin of Wadsworth, Ohio, strongly support expanded newborn screening. They first learned about it many months after the birth of their daughter Grace.
"The first eight months she did nothing but cry," Sandy says. "She couldn't sit up or hold her head up. She wasn't interested in anything that went on around her." The reason? Grace was born with a rare genetic condition called methylmalonic acidemia (MMA), which, left untreated, can be fatal. In this condition, cells lack an enzyme needed to metabolize protein.
Unfortunately, at that time, the state of Ohio did not screen for MMA. Grace and her parents suffered for 11 months before she was finally diagnosed with the disorder. Although developmentally delayed in some areas, Grace now benefits from a low-protein diet, takes medication regularly, and is getting better every day.
By measuring chemicals found in just a few drops of blood, newborn screening can identify metabolic disorders—inherited illnesses that lead to the accumulation of toxic chemicals in the brain and other vital organs. The goal is to catch affected newborns and begin treatment before symptoms occur. If undetected, these disorders can lead to mental retardation , cerebral palsy , and even sudden death.
Newborn screening has been available for many years, but recent technological advances have expanded and improved the test. A method called tandem mass spectrometry analyzes dried blood spots obtained by pricking a newborn's heel.
Currently, all states require that newborns be screened for phenylketonuria (PKU), galactosemia , congenital hypothyroidism , and hemoglobinopathies (eg, sickle cell disease ). The March of Dimes recommends that 29 diseases be included in neonatal screening. The goal of expanded screening is to identify babies who have a disorder that is not tested for by state programs. The National Newborn Screening Status Report gives detailed information on the testing available in each state.
Like most people in their situation, Dale and Melanie Ruff of Franklin, Tennessee, were shocked to learn they both carry a gene for a metabolic disorder. The Ruffs found this out when their little girl Anna was diagnosed with medium chain acyl-CoA dehydrogenase deficiency (MCAD) when she was 17 months old. Known as a "silent disease," MCAD strikes when a child has fasted for a few hours, as children tend to do when they get a cold or the flu . Unfortunately, most states do not screen for MCAD, even though it is seen in one out of every 12,000 to 13,000 babies.
After getting a stomach virus, "Anna went to bed early one night and the next morning was unresponsive," says Melanie. Anna is one of the lucky children with MCAD, because she survived her first crisis long enough to be diagnosed and treated. It is estimated that about 25% of children with MCAD die during their first episode. "We had never heard of this disease, and there was no history on either side of the family," says Melanie.
Surprisingly, most families who have a child affected by a metabolic disorder have no family history. Genes for these diseases can be passed along through generations of healthy people without anyone ever knowing about them. These "carriers" are healthy because the normal gene in the pair (genes come in pairs—one from each parent) is working, making up for the flawed gene. But when two people who coincidently carry the same flawed gene get together, their risk of having an affected child is 25% for each pregnancy. This pattern, called recessive inheritance, explains how most metabolic diseases pop up unexpectedly.
Metabolic conditions are rare. Approximately one in 5,600 newborns is affected, according to Baylor. Screening at birth can identify these infants even before symptoms develop in some cases, allowing treatment to start early.
Thousands of babies die each year of unexplained causes, such as sudden infant death syndrome (SIDS) . Dr. Charles Roe, medical director of the Institute of Metabolic Disease at Baylor University Medical Center in Dallas, is a renowned expert on this subject. Dr. Roe thinks that up to 3% of babies diagnosed with SIDS actually died of a metabolic disorder. "The greatest problem with the recognition of inherited metabolic diseases is thinking of them in the first place," Dr. Roe explains. "It is not commonly part of a differential diagnosis."
Consider expanded newborn screening if:
If you are considering expanded newborn screening for your baby, talk with your pediatrician about having this test done and arranging to have extra blood taken at the time the state-required screening is performed. Also, call one of the resources listed below to request a free kit, which includes instructions for testing. Some pediatricians and general practitioners may be unfamiliar with expanded newborn screening, so you may need to provide information.
"A few more drops of blood can (allow a lab to) test for all these diseases," says Melanie Ruff. "It should be an option for all parents."
March of Dimes
National Newborn Screening and Genetics Resource Center
Ontario March of Dimes
Save Babies Through Screening Foundation of Canada
Kayton A. Newborn screening: A literature review. Neonatal Network. 2007; 26:85-95.
Levy HL. Newborn Screening by Tandem Mass Spectrometry: A New Era. Clinical Chemistry . 1998;44:2401-2402.
Wilcken B, Wiley V, Hammond J, Carpenter K. Screening newborns for inborn errors of metabolism by tandem mass spectrometry. N Engl J Med . 2003;348:2304-2312.
Last reviewed January 2009 by Kari Kassir, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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