HOLLYWOOD A-lister Robert Downey Jr has proved a real life superhero after promising to help an Alexandria boy who is battling a deadly disease.

Iron Man-daft younger Aaron Hunter saw his dreams come true after his idol gave him a FaceTime call following a viral appeal.

Aaron's mum Elizabeth said: "He was absolutely delighted Robert Downey Jr gave him some Face Time.

"They chatted for around half an hour about his films and some of the sequences and Aaron asked him if he'd help in his appeal and he said he would."

The Reporter told in March how seven year-old Aaron called on the Avengers superhero for help in beating his deadly disease.

Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation - or ROHHAD - is an extremely rare, life-threatening, limiting, and complex medical condition affecting approximately just 100 children worldwide.

In a very touching video, Aaron said: “Iron Man, if you see this I really, really need your help.

“I have a very bad disease called ROHHAD and it’s really hard sometimes.

“The doctors don’t have a cure yet - some of my friends with ROHHAD have died.

“I don’t want any more of my friends to die. We need your help, Iron Man.”

And charity, the ROHHAD Association, confirmed the appeal reached Downey Jr. who has been playing the superhero on the big screen since 2008- and he'd been in touch.

Elizabeth said: "It was incredibly moving and magical.

"After the call finished Aaron came over and gave me a cuddle and started crying tears of joy.

"He said: "Iron man's going to help me!"

During their chat, Aaron asked him the question that he has been so desperate to ask; ‘Can you please do my #GOMADJUMPFORROHHAD Challenge? and help me raise awareness for all the ROHHAD kids around the world?’”

The challenge came about based on Aaron’s love of jumping in puddles.

Therefore, he’s asking people to jump up and down in a puddle for one minute to raise, not only awareness of his condition, but also vital funds.

Elizabeth said: "Robert said to Aaron that he's going to help and he'll do the challenge soon, which is amazing.

"He told him he would love to do his challenge and made him feel so special.

"Iron Man has answered our brave boy's plea for help and in doing so has made him the happiest little boy in the world!

"He has not stopped smiling since and told us he feels he is the luckiest boy in the world because he is now best friends with Iron Man!"

Now it's hoped that with Iron Man on board, ROHAD can be promoted even further and that more money can be raised to one day find a cure.

Downey Jr is not the only high profile figure one to meet up with Aaron.

First Minister Nicola Sturgeon has also personally chatted to the brave seven year-old as he tries to promote his condition and, at the same time, campaign for more research into a possible cure.

To view Aaron's video go to http://www.rohhadassociation.com/

To find out more go to the ROHAD Association's Facebook and Twitter sites.