Every state including Arizona has a newborn screening program which tests every newborn for a series of metabolic disorders, hormone or hemoglobin problems, and other things like cystic fibrosis and hearing loss. The metabolic, hormone, and hemoglobin disorders are tested with a simple blood test right after birth and again a couple weeks later (three blood spots from a heel stick on a sheet of special paper). The paper with the blood spots is sent to a lab for the tests with special instruments. In Arizona those tests are done at ADHS’ Arizona State Laboratory.
Getting the tests turned around fast is important because if there is a problem, parents and doctors need to know right away so the baby can get on a special formula or other intervention. In Arizona, those turn- around times are 95% of samples completed within 5 days (after an intervention we did in 2013). ADHS also has folks that follow up with doctors about the results.
Over time, new disorders have been added to the screening panel. Before things are added to the screening panel public health folks do a deep dive to make sure that there is a clear relationship between the thing you’re screening for and the disease and disorder and whether there’s an intervention that can be implemented to help improve the chances pf a good outcome for the baby if he or she tests positive.
You also need clear “cut off” values, to minimize the number of false positives and negatives. After all, you want to catch all the screening tests that are truly positive while making sure you don’t say a test is positive when the baby really doesn’t have the condition (to avoid parents unnecessarily freaking out and to avoid inappropriate therapies).
Is there a newborn screening test to for Sudden Infant Death Syndrome?
For many years we’ve known about environmental risk factors for Sudden Infant Death Syndrome or SIDS. The big ones have to do with the sleep environment. Parents can do several things to minimize SIDS risk like make sure baby sleeps on her back, keep the crib as bare as possible, don’t over blanket baby so he or she gets hot, have the baby in your room BUT NOT IN YOUR BED, offer a pacifier, and never smoke around the baby and don’t smoke in the house: Sudden infant death syndrome (SIDS).
So far there haven’t been any clear blood or other tests identifying clear physical risk factors. Perhaps until now at least.
Last week a study was published called: Butyrylcholinesterase is a potential biomarker for Sudden Infant Death Syndrome. The authors suggest that they found a relationship between a baby’s Butyrylcholinesterase (BChE) level and a risk for SIDS. In the study, the researchers compared the BChE levels of infants that had an unexpected death classified as SIDS to matched controls.
The researchers found that:
Conditional logistic regression showed that in groups where cases were reported as “SIDS death” there was strong evidence that lower BChE specific activity (BChEsa) was associated with death (OR=0·73 per U/mg, 95% CI 0·60-0·89, P=0·0014), whereas in groups with a “Non-SIDS death” as the case there was no evidence of a linear association between BChEsa and death (OR=1·001 per U/mg, 95% CI 0·89-1·13, P=0·99).’
We found that Butyrylcholinesterase Activity, measured in dried blood spots taken 2-3 days after birth, was significantly lower in babies who subsequently died of SIDS compared to living controls and other Non-SIDS infant deaths. This study identifies a biochemical marker that differentiates SIDS infants from control cases and those dying from other causes, prior to their death. We postulate that this decreased activity of Butyrylcholineserase represents an autonomic cholinergic dysfunction and therefore an inherent vulnerability of the SIDS infants.
Should we add BChE to Arizona’s newborn screening panel?
Maybe, but we’d need to answer a few questions first.
Is it possible? Yes. The ADHS instruments can test for this enzyme.
Is there a clear relationship between the enzyme level and a baby’s risk for SIDS? Maybe. This study is new and had a small sample size, although the statistical relationship was clear. More research confirming the link should be done before routinely testing for and reporting BChE levels.
Is there a clear intervention? Yes. Even though all parents are encouraged to follow the SIDS prevention techniques, it’s reasonable to think that parents that were told their child is at higher risk for SIDS because of their blood BChE level would be more vigilant about making sure they’re always following all the recommendations.
Next steps: Arizona’s Newborn Screening Advisory Committee is likely to hear about this new study and will likely explore whether it should be added to Arizona’s panel. No doubt the committee will also explore the questions above before making a recommendation to the (next) ADHS Director about whether the ADHS Arizona State Laboratory should add this new test to the screening panel.
