At 1 a.m., most people are fast asleep in their beds. But Charlotte Phillips sometimes finds herself up at that odd hour, waiting anxiously in a deserted Missouri parking lot far from her home. Phillips drives there to meet a contact for a very special delivery: a packet of cheek swabs and blood samples from a newborn Mennonite baby at risk of a life-threatening genetic condition called maple syrup urine disease (MSUD).
For more than two decades, Phillips, an NIH grantee at the University of Missouri, Columbia, has volunteered to ensure that the DNA in these swabs and samples is tested for MSUD within hours of a baby’s birth. If found to be positive for the condition, the baby can receive a needed special formula. Without it, the baby would suffer brain damage within days from its inability to break down amino acids in protein-rich foods, including breast milk and standard infant formula. Hurrying off at a moment’s notice isn’t always convenient, but Phillips, who is not Mennonite, feels a personal calling to do it. She wouldn’t want any babies to die.
MSUD is named for the sweet smell associated with the urine of people left untreated for the condition. The lifelong condition is exceedingly rare, affecting about 1 in 185,000 infants . But, it’s relatively common among Old Order Mennonites, affecting about 1 in 380 infants. That’s because many Mennonites carry one copy of the mutated gene, meaning they won’t develop MSUD but can pass it on to their children if their spouse is also a carrier.