Via explains that Dad's family is Jewish, while Mom's family is Brazilian. Except for Grans and Grans' husband, who lived in the U.S., everyone else still lives in Brazil. Mom and Dad met at Brown University and have been together ever since. They moved to North River Heights in upper Manhattan when Via was a year old. Until August was born, nobody knew that they were carriers for his genetic mutation. Though sometimes his condition can be caused by mutations during pregnancy, in August's case, he is the way he is because both Mom and Dad are carriers for the gene. Via explains that she's also a carrier for the gene.
By introducing basic ideas of inheritability and biology, Via begins to show how parts of a person's identity are solidified long before they're even born. Especially since the most identifiable part of August's outward identity came from mutations in his parents' genes, this also shows how one's parents have the power to pass on not just hair color or height, but to pass on traits that can make a child more susceptible to bullying.