When hospital personnel take a small drop of blood from a newborn's heel, they are taking material for a genetic test. However, they are not going to analyze the DNA from that blood sample. The blood, trapped on a piece of filter paper, will be examined in a tandem mass spectormeter. This machine looks for specific chemicals within the blood, chemicals that accumulate if the newborn has certain genetic conditions, such as phenylketouria.
The number of tests now being conducted varies considerably across the country. I wrote some time ago about additional tests now required in Florida. Today's news was about Virginia. Seventeen disorders were added March 1 to the list of 11 disorders already screened for in newborns.
Most of the disorders are rare. Last year 129 children were found to have a genetic disorder. This year, the state expects to find an additional 46 cases, based on the increased number of disorders being tested.
Parents may refuse the testing for religious reasons.
According to the article in the Winchester Star,
With modern technology it’s possible to screen for hundreds of diseases. But it’s only helpful to screen for diseases that can be treated, said Dr. Bryan Kornreich, with Pediatric Associates of Winchester and chairman of WMC’s Pediatrics Department.
Dr. Kornreich was also quoted as stating:
Because screening tests are designed to catch anyone who could possibly have the disorder, they sometimes show false positive results, he added. More tests are required before an actual diagnosis is made. The testing is expensive and stressful for parents and child.
But, he recommends that additional testing not be done unless there's a family history of the disorder.
A national panel is suggesting that states broaden their newborn testing programs to include more of the disorders that can be treated with diet changes. These treatments can prevent brain damage. For more information on newborn testing, check with the March of Dimes or your pediatrician.
Marie Godfrey, PhD