THE mother of an autistic boy, who was tortured in a “depraved” attack by two teenage girls, has told a court it breaks her heart that she couldn’t protect him on that day.

The 12-year-old boy says he has nightmares after the assault, and asks his mother why they targeted him.

The boy was enticed into a construction site by the girls, aged 13 and 14, where they stripped him naked, made him eat human faeces and smeared it over him.

The girls, who can’t be named, also punched and kicked him and sexually abused him in the attack at Kalynda Chase, Queensland on July 15, 2012.

The boy’s mother said her son would never be the same.

“He asks me ‘why me mum, why me?’,” she said.

“It breaks my heart ... what can you say to a little boy when you should be able to protect him?

“As his mum this has caused me so much hurt and pain that I couldn’t protect my boy from such disgusting, life-threatening, revolting acts.”

The girls, now aged 14 and 16, pleaded guilty this week to torture, deprivation of liberty, attempted rape and assault occasioning bodily harm.

Both girls broke down in tears when Crown Prosecutor Kelly Stone detailed the grisly details.

Each of them have written a letter of apology to the boy’s family.

Judge Stuart Durward SC adjourned their sentence overnight, to clarify a part of a psychological report.

In the section, the younger 14-year-old defendant was reported to laugh after being asked by a psychologist about the events on July 15, 2012.

The girl then said “when I get out (of detention) I’m going to find the little c--- and bash him”.

The boy’s mother told her son’s attackers how they’d changed her family’s lives.

“Those days of (my son) enjoying his outdoor life has gone ... he lost his smile for a whole year,” she said.

“This has been replaced by a young boy too afraid to go out on his own, unsure of everyone.”

Barristers Viviana Keegan and Claire McKinnon described each girl’s upbringing as tough, with both of them in state care at the time of the attack.

Both girls, who are not related, made allegations of being sexually abused when they were younger but the claims never progressed to court.

The 14-year-old girl has been in more than 50 different foster homes, and at one stage was bashed by her father so severely she required a full body cast.

Ms McKinnon said her father received a wholly suspended jail sentence for the attack.

A case worker told the court the 14-year-old girl hardly sees her younger brothers as they are both too scared to see her.

Mr Stone, for the prosecution, said the attack was depraved.

“While the physical injuries suffered by the complainant are not the most serious ... the depravity of the conduct in relation to the psychological pain takes it to that level of seriousness,” he said.

Their sentence will resume today.