A 7-year-old boy suffering from a rare disorder died on Sunday, one day after receiving the rare title of honorary Marine - and just shy of his eighth birthday.

When I was a college sophomore living in a sorority house at the University of California at Santa Barbara, my parents called to tell me that my baby brother, Gavin, was dying. He had been given a diagnosis of a very rare disease, Aicardi–Goutieres Syndrome.

The doctors immediately placed him in hospice care.

He was 4 months old.