At the tender age of 8, Dylan Siegel has accomplished something that many authors only dream of — nearly hitting $1 million in book sales. But the young author has not kept a single penny of his profits. Instead he has donated every cent to help cure a rare disease from which his best friend suffers.

Dylan wrote his book, "Chocolate Bar," planning to donate any profits to the University of Florida where research is being done to find a cure for glycogen storage disease (GSD) — a condition his best friend, Jonah Pournazarian, has been living with since birth.

GSD affects the body's ability to use and store glycogen. Jonah was diagnosed with the disease when he was just 6 months old, and he must be fed a special formula directly into a stomach tube each day. Dr. David Weinstein, the lead researcher for the Glycogen Storage Disease Program at the University of Florida, told ABC News that his research was almost out of funding before the Siegel family approached him about raising money for the program.

Since 2013, when Dylan penned (or markered) "Chocolate Bar" at age 6, the book has sold 21,000 copies to readers in 56 countries. 

And now, nearly $1 million later, Weinstein told Fox 17 News that the dream of curing these children with GSD might soon become a reality.

Check out the "Chocolate Bar" website to purchase a copy and learn more about Dylan and Jonah's story.

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8-year-old author raising $1M for best friend's disease
Dylan Siegel describes his friendship with Jonah Pournazarian as "awesome as a chocolate bar," which is where he got the title of his book.