12-Year-Old Asks Santa for New Heart for Mom in Touching Letter

— -- One 12-year-old boy's tearjerking request to Santa has local firefighters showing him love this holiday season.

Arnulfo Guerra Jr. wrote a letter to St. Nick two weeks ago asking for a healthy heart for his mom. When it reached the Channelview Fire Department in Channelview, Texas, first responders surprised the boy with a new bicycle and some toys from the community toy drive.

"It was pretty heartwarming," said Justin Wischnewsky, fire captain of the Channelview Fire Department in Channelview, Texas. "All he wanted for Christmas for his mom to be okay. It's gut-wrenching ... there are good kids out there. We said, 'There's not a whole lot we can do, but let's try and make this the best Christmas ever for him."

Arnulfo's letter was passed along from his school, Anthony Aguirre Junior High, to Channelview FD, Chief Wischnewsky told ABC News.

It read:

Dear Santa,

I believe in you and the miracles, Santa I don't want toys for me, only I want a [healthy] heart for my mom, she's sick, her diagnostic is transposition of the great [arteries] (T.G.A). I'm sad for her she's 46 years and I only 12, next March 18 I will be 13 teen, we need her for many years more, me and my Dad pray all days for mom. Only I want is to see my mom [healthy] and happy.

Thanks Santa,

Love you!!

Arnulfo's dad, Arnulfo Guerra Sr., of Channelview said his wife Santos' heart defect has her on the waiting list for a donor in Houston. She's been on the list for one year, but doctors told him to prepare to wait for five years, he told ABC News through a translator.

"That's the only thing I want for Christmas," Arnulfo Jr. told ABC-owned television station KTRK in Houston.

Guerra Sr. said the fire department made his son feel "so special" and that his letter made him "very happy."

"My wife is very happy," he added. "We’re all very happy."

ABC News' Tara Fowler contributed to this report.