Ten-year-old Scotty Sell is considered a social butterfly, spending most of his time laughing and smiling.

But the East Amherst youth also has a severe neurological disorder, Angelman Syndrome, characterized by serious developmental delays, seizures, sleeping problems and jerky movements. Also, he says only a few words, and he’s legally blind.

Children diagnosed with Angelman’s have two rather unusual traits. They tend to be obsessed with water, enjoying and being comforted by swimming, bathing and showering. And they tend to have a very happy demeanor, the way Scotty does.

“He’s so happy,” said his mother, Rita. “He giggles. He laughs. It’s amazing how happy he is. He just reminds me to find joy in every little thing.”

The disorder, previously diagnosed in 1 out of 30,000 children, now is found in about 1 in 15,000 to 20,000. Friday was International Angelman Day; Feb. 15 was chosen partly because the syndrome results from a problem with the mother’s chromosome 15. And the cause has an internationally known spokesman now, movie actor Colin Farrell, whose son James has the disorder.

Farrell, in a statement, called Friday’s awareness day “a celebration of our children” and an opportunity “to introduce more people to both the beauty inherent in and the trials faced by those with AS.”

Scotty’s world exhibits both the beauty and the trials.

He adores music, everything from rock to hip-hop to country. Family members call him a rock star or the “condiment king,” because of his love for sour cream, ketchup and syrup. When French toast or pancakes are on the menu, he’s known for pouring syrup all over his tongue – and his face.

Through his parents, Rita and Scott, he is on a mission, to promote recognition, understanding and respect for people with Angelman’s.

“We want to raise awareness, but also acceptance,” his mother said. “When we go to the park, I want kids to go up to him and play with him. There’s still a stigma, and parents still keep their kids away.”

Scotty’s life story sums up the change in awareness about Angelman’s.

Born in April 2002, at 9 pounds 11½ ounces, he was taken to the Sisters Hospital Neonatal Intensive Care Unit, with significant breathing problems. He was different from the beginning, exhibiting limited eye contact and very little muscle tone. He didn’t sit up on his own until 2½ and didn’t walk until he was 3½. He also has had frequent seizures, developmental delays, lots of allergies, toilet-training issues, acid reflux and sleeping problems.

At age 1, he was diagnosed with cerebral palsy and epilepsy, after doctors had ruled out just about every other neurological cause.

Finally, when Scotty was 6½, a Women & Children’s Hospital neurologist, Dr. Arie Weinstock, suggested that one of his medications was making his seizures even worse. He was weaned off that drug, and a year later, the doctor asked Rita Sell whether she had heard of Angelman Syndrome.

She knew about it, from her own professional training as a psychologist, but she thought the syndrome was characterized by wildly flapping arms and severe mental retardation. When she Googled the syndrome, she found about 30 characteristics, with Scotty having 29 of them.

“That was comforting,” she said. “For 7½ years, I hadn’t met anyone like Scotty.”

At the same time, Rita Sell wonders whether Scotty would have progressed so much if they had known his diagnosis years earlier.

“I was in a healthy denial, and we just pushed him past his expectations,” she said.

Like the parents of any child with a disability – or any parents – the Sells have had some wonderfully triumphant moments with Scotty:

• “He has a few words,” his mother said. “He says ‘Momma.’ He says, ‘C’mon, Mom.’ I’ve heard him say, ‘I love you, Mom.’ I just melted.”

Rita Sell even was thrilled by his saying an R-rated four-letter word, because it showed he could make the “sh” sound. On Christmas Day 2011, a 9-year-old Scotty went through all the gifts under the Christmas tree and read whether each one was for him, his parents or his older brothers, Ryan and Christopher.

“Once he found his pile, he plopped himself down and started opening his own gifts,” his mother recalled.

Family members get a kick out of seeing what a social butterfly he is at his school, Aspire of Western New York.

“He says hi to everybody, waves to every teacher, student and adult, and if he doesn’t get their attention right away, he gets louder, to make sure,” his mother said. “I call him the Mayor of Aspire.”

Since her son’s diagnosis, Rita Sell has become more active with developmentally delayed children. She has her own business, Blessed Beginnings Family Services, which coordinates services for families needing early intervention for children with such delays.

On Friday, Sell family members were looking forward to going to Ruby Tuesday’s on Walden Avenue, which was donating 20 percent of everyone’s bill that day to Angelman Syndrome research.

“I always felt society looked at kids like Scotty as a curse or burden,” his mother said. “But he’s a blessing. This is not a mistake. This is not a mutant. There is a purpose for him being here.

“I think he’s helped other kids get diagnosed earlier,” she added. “That’s huge.”