Dad runs Boston Marathon to honor unborn daughter with Down syndrome

A father's love for his unborn daughter has inspired a 26.2-mile run through the streets of Boston and has raised tens of thousands of dollars to benefit others with the same diagnosis.

Oliver and Kinnon Foley of Charlestown, Massachusetts, are less than a month away from the birth of their first child, a girl they named Tenley.

When Kinnon Foley was 11 weeks pregnant, they found out that their daughter would be born with Down syndrome.

"About six weeks after the diagnosis, the idea struck me — this would be my best opportunity to run a marathon," Oliver Foley told ABC News. "I learned the Massachusetts Down Syndrome Congress had one bib left. It felt like it was meant to be."

Down syndrome, also called trisomy 21, results when a person has three copies of the 21st chromosome. Typically people have two. The effects of the extra chromosome vary widely among people with Down syndrome, but it can cause developmental and physical challenges. Almost 1 in 800 babies in the U.S. is born with Down syndrome, according to research published in The American Journal of Medical Genetics. 

The Foleys first connected with the organization soon after Tenley's diagnosis. They were referred by "every doctor and geneticist" to the MDSC first-call program, which connects parents new to a Down syndrome diagnosis, whether pre- or postnatal, with families that had similar experiences.