"This leads to two conclusions. First, we need to more deeply assess this hypothesis by conducting umbilical cord blood tests that measure neonatal levels of this growth factor, and then match those results against future autism occurrence in the maturing child.
"Second, those who embrace the hypothesis that IGF is indeed an autism biomarker should advocate and encourage breastfeeding as a highly accessible means of supplementing an infant's natural levels of the protein."
If a newborn's innate supply of IGF were found to be low, Steinman said, the infant could receive supplemental amounts of the protein - via breastfeeding or through other relatively simple means - that could then contribute to more-effective brain function as the baby develops into an active child.
The study is published in journal Medical Hypotheses.