How often, when taking an over-the-counter drug, did you read the following note on the label: “adults and children 12 years of age and over: one tablet; children under 12 years of age: ask a doctor”? Pretty often, I guess. And I’m sure that the fact that children should take drugs differently from the adults doesn’t surprise you. But what is so magic about the age 12 in this particular case? What if the age of your child is 11 years and half? 11 years and 11 months? Will you “ask a doctor” or take a risk of giving your little one the much-needed relief?

Welcome to the world of pediatrics, a branch of medicine that deals with children’s medical care! Conventional definitions of a “pediatric patient,” a scientific term for a child, bracket the childhood into the age period ranging from birth to 18 years (although some professional organizations in the United States extend the age limits of pediatrics “from fetal life until age 21 years.”) Yet it’s clear that while such a range may make legal sense, it’s too broad to be useful in real medical practice. As one report put it, it’s ridiculous to compare “a 34-week-old premature infant” with “a 17-year-old high school football player.” To address this problem, more precise age definitions have been introduced, dividing “pediatric patients” into neonates, infants, toddlers, preschoolers, school-agers and adolescents. However, with so wide variations in the rates of individual child development–not to mention cases of physical and mental retardation–placing specific age numbers doesn’t really help.

There is one parameter, though, that seems reasonable, at least for the purposes of dosing drugs: weight. For example, San Mateo (California) County’s medical guidelines define pediatric patients as someone weighting less than 80 pounds. But again, with the spread of childhood obesity reaching epidemic proportions, a child’s weight can be grossly misleading.

We therefore urgently need better predictors of children’s real, ontological, age. I’d call them the biomarkers of childhood (BOC). We need to identify and validate a series of markers–naturally-occurring molecules collected from easily available body fluids, such as urine and saliva–to follow stages of a child’s physiological and mental development. These markers will tell us how our child progresses through his or her childhood; these markers will eventually tell us that our child has reached adulthood.

I see at least two areas where BOC can be used. First, and the most obvious, is medical care. The utility of biomarkers for pediatric healthcare has been recently reviewed; suffice it to say here that the available information on validated biomarkers for children is limited at best. This has negative consequences for both pediatric care and for the development of drugs targeted at children as well.

Second, why restrict BOC to medical use? Why not to ask more general question about the biological differences between children and adults? What does make your child a child? And although answering this question will require contribution from many different fields, BOC could provide objective and measurable input. I easily see their application in the juvenile justice system, to begin with.

Given the enormous amount of information needed to create a comprehensive list of BOC, it’s clear that this job is well beyond capacity of one single person or even organization. The most reasonable venue is to use a crowdsourcing approach that would allow collecting data points from anyone anywhere around the world.

I therefore call on any party interested in child healthcare and well-being–whether commercial, government or non-profit–to sponsor a crowdsourcing campaign aimed at creating a comprehensive list of BOS. Moreover, I volunteer to work with any non-profit entity to help define specific parameters of the campaign and to choose an appropriate crowdsourcing platform.

Image credit: portsmouthchildrensdentist.com