LOUISVILLE (REUTERS) - A six-year-old Kentucky boy born with a malformed right hand because of a rare disorder has received what he called his best Christmas gift ever - a "bionic" prosthetic made from 3D printing technology.

Lucas Abraham, who has wanted a working right hand since he was two years old, showed off the new prosthetic made by University of Louisville bioengineering students.

"It's better than every gift that I've ever had before," Lucas told a news conference at the university on Wednesday.

Prof Gina Bertocci, a University of Louisville bioengineering professor, said Lucas' hand was the first created by the school for a child and that more could be produced.

The university described it as "bionic".

The printer technology greatly reduces the manufacturing cost and the plastics used are similar to those in Lego blocks, allowing the devices to be produced in various colours, Prof Bertocci said.

Children like it because it makes them look like a Transformer, she added, saying: "Everyone wants to show off their hardware."

The students received assistance from e-NABLE, a global volunteer group that designs and prints prosthetics.

Three hands composed of plastic, leather and wire were made to fit Lucas.

He will keep two and the university will retain the third for accreditation purposes, the school said.

Within minutes of receiving his new hand last week, Lucas was able to grasp a ball.

He wore the hand to school and was able to shake hands and give his classmates high fives.

It also will let him crash cymbals together in music class, Lucas said.

His grandmother Julie Abraham said he had shown more confidence in himself since receiving the hand.

She had written to the university in August asking if it could do something for him.

"It's a pretty good Christmas gift," she said.