The Australian-born, London-based writer and mother-of-two has revealed she once thought her bright and charming son would end up "living in a bedsit on benefits" as teachers and employers overlooked his potential because he was "differently abled".
"When my autistic son was nine he came home with a sign sticky-taped to his back saying 'Kick me I'm a retard'," Lette writes.
"Tearing up, he stammered, 'The kids call me a retard... What is a retard?' You might as well have ripped my heart out of my chest and stomped on it."
Despite having "an encyclopedic knowledge of the Beatles, Buddy Holly and Shakespeare, including most of Hamlet's soliloquies", Jules was put on detention at school for misinterpreting homework, while constant belittling from his classmates gave him low self-esteem.
When my autistic son was nine he came home with a sign sticky-taped to his back saying 'Kick me I'm a retard'.
By high school he found himself "exiled to Social Siberia" and spent his days trying to "make himself invisible". But it was job-hunting that really brought home the prejudice people with autism can face, as one employer after another rejected him for being different.
She recounts the shocking statistic that while people on the autistic spectrum often have a very high IQ, less than 15 per cent are in the workforce.
"Although wackily bright and quirkily charming, the only future I could envisage for Jules was living in a bedsit on benefits," Lette recalls.
"These daily rejections is why it's vital to tell your special needs child that they really are special. It's imperative to find what they're good at and encourage it. It doesn't matter if it's moth wing fluctuations, igneous rock formations or Tibetan nose fluting - because you never know what their obsession could lead to."
When Jules wanted to study acting, Lette had her doubts about his ability to empathise with a character's complex emotional nuances, but she enrolled him in an acting course.
Not only did he excel in class productions, he was cast in two short films, won an acting award, and then secured a part on the BBC medical drama Holby City.
A semi-regular on the show since October, he is watched by six million people a week, gets stopped for autographs and has a fan page dedicated to him.
"As he bathes in praise from BBC producers, cast and crew, I think back to those school bullies and occasionally allow myself a little moment of light gloating," Lette says.
"But my main hope is that Julius' success will encourage other employers to think outside the neurotypical box and hire the 'differently abled'. We should stop forcing autistic people to act normal, and help them to become their best autistic selves by focusing on what they can do instead of what they can't."
Jules, who graduated from Access All Areas' and Royal Central School of Speech and Drama's Performance Making Diploma for Adults with Learning Disabilities, says his role on Holby City has been life-changing.
"I usually sleep until lunchtime, but now I jump out of bed at 6am in the morning to be in make-up by 7.30 and that makes me feel alive," Jules said in an interview for Access All Areas.
He says it's important that characters with Autism Spectrum Disorders (ASD) are played by actors with ASD, rather than neuro-typical actors.
"I have had to fight this condition my whole life and I know just how hard it is, so I can bring that experience to the role," he said.
"OK, Dustin Hoffman was great as the Rain Man but I still think I can bring a special edge, something extra to a role like that.
"I think Hamlet was on the Autistic spectrum, so maybe one day I will play the Asperger's Hamlet. I don't have a girlfriend at the moment so I'd love to play Romeo."