Siblings Amber and Blake Nelson suffer from mitochondrial disease, a rare disorder that robs their young bodies of the energy they need to function properly.

To help raise money for research into the condition, their parents, David and Melissa Nelson, have illuminated their home in Devlin Avenue, North Nowra, in the hope people will donate to the cause.

They have also put up signs in an effort to increase awareness of the affliction suffered by their children.

Mr Nelson said awareness was a key issue.

One mitochondrial disease sufferer was the child of a doctor who knew nothing about the condition. Once the child was diagnosed, Mr Nelson explained, the doctor had since spent time trying to educate other doctors.

Kim Webb-Wagg, who looks after the two children after school, has joined the Nelsons in their efforts.

She has also decorated her Illaroo Road home in an effort to encourage donations and more awareness of mitochondrial disease.

There are more than 150 varieties of mitochondrial disease.

Blake and Amber suffer from the variety known as Leigh’s Disease, which typically results in lesions on the brain along with heart, breathing, kidney and vision problems because key organs are unable to get they energy they need to function properly.

Already seven-year-old Blake and Amber, who will turn 10 later this month, suffer problems with their speech and balance, while Amber quickly runs out of energy and needs a wheelchair to get around.

However in the first months of her life Amber appeared to be developing normally, and at eight months was pulling herself up on furniture. However she did not walk on her own until days before her second birthday.

It took years and a wide range of tests to diagnose the condition, however once medical specialists knew what they were looking for they were able to diagnose Blake with just a blood test.

There is no cure for Leigh’s Disease, however Amber and Blake are being treated with a cocktail of vitamin supplements in an effort to stave off the inevitable deterioration that will follow the degenerative disease.