The family of Maxwell Begley, a 13-year-old autistic boy from Ontario, recently received a deeply disturbing letter from "one pissed off mother" who called for his parents to "do the right thing and move or euthanize him."

"You selfishly put your kid outside everyday and let him be nothing but a nuisance," the letter reads. "He is a hindrance to everyone and will always be that way. ... No employer will hire him, no normal girl is going to marry/love him."

"Personally, they should take whatever non retarded body parts he possesses and donate it to science. What the hell else good is he to anyone!!!" it continues.

“It made me sick to my stomach to think that somebody hated my son that much and they didn’t even know him,” Max's mother, Karla Begley, told the Toronto Star. “But they just hated him because he was different. That’s the only reason they had to hate him.”

“He doesn’t know anything about the letter,” Karla said of her son's reaction. “He loves the attention, he thinks he’s famous.”

Lennon and Maisy Stella, two young Canadian sisters who sing and star on ABC's "Nashville," used their sizable Twitter presence to call attention to the frightening missive. On Sunday, they shared a photo of the letter that has since been retweeted nearly 6,000 times.