CHICAGO — Sho Yano’s mother hands him his lunch for school in a brown paper bag.

“You don’t need any bones today? No bones?” Kyung Yano asks her quiet, spectacle-wearing 12-year-old, who shakes his head “no” as they head out their apartment door. She wants to make sure he isn’t supposed to take his samples of spinal bones and a human skull to class, where he’s learning about human anatomy.

It’s the kind of morning many young students and their parents experience — except for one thing. Sho isn’t in junior high. He’s a first-year medical school student at the University of Chicago, where he’s the youngest ever to attend one of the university’s professional schools.

If he wasn’t also getting his Ph.D. along with his medical degree — thus, pushing his age at graduation to 19 or 20 — he’d also be on course to become the youngest person to graduate from any medical school. According to the “Guinness Book of World Records,” a 17-year-old graduated from medical school in New York in 1995.

Yano is uninterested in setting records and shuns the labels often used to describe him — “prodigy” and “little genius” among them.

Although, he has an IQ over 200, and he graduated in three years from Chicago’s Loyola University, summa cum laude, going to school is about learning as much as he can.

Yano spent the summer dissecting a human cadaver and learning the intricacies of the 12 cranial nerves. So far, having scored A’s on his first few quizzes, he’s handling the coursework better than some who are a decade or more older.

Some of his classmates were wary at first, including Luka Pocivavsek, a 22-year-old medical student who shared a room with Yano at a retreat for new students in the M.D./Ph.D. program.

At first, he thought Yano — who often pauses to ponder questions before answering and chooses his words carefully — was very quiet. He wondered how such a young student could handle the emotional and social rigors of being a doctor.

Yano quickly won him over.

“He has surpassed my expectations in every imaginable way,” Pocivavsek said. “His initial shyness has given way to a very sociable guy. And his understanding of complex social and political issues is very keen and observant.”

The medical school adjusted Yano’s schedule a bit, delaying his clinical work with patients for his last two years in the program.

Still, pathology professor Tony Montag said he sometimes forgets that Yano is younger than his classmates.

“Of course, to me, they’re all kids. So he doesn’t seem particularly different than any of the students,” says Montag, who teaches Yano and other first-year students about microscopic tissues in their histology class.

Born in Portland, Ore., Yano spent his early years in California, where is father, Katsura, runs the American subsidiary of a Japanese shipping company. Yano lives in the university’s family housing with his mother, who came to this country from Korea to study art history, and 7-year-old Sayuri, a talented student in her own right who wants to be a cardiologist.

From early on, his mom says it was apparent that Sho was gifted.

His mother recalls trying to master a waltz by Chopin on the piano while 3-year-old Yano played with toy trains below her. Frustrated, she went to the kitchen to take a break — and a few moments later, hurried back as she heard Yano playing the piece.

By age 4, he was composing. And by age 7, he was doing high school work — taught by his parents because they couldn’t find a school that could accommodate him.

By age 8, he scored a 1,500 out of 1,600 possible points on the SAT and started college at age 9.