A new drug trial in Melbourne hopes to help girls with a rare and incurable syndrome that leaves them struggling to speak, walk, eat and even breath.

Up to 30 patients with Rett syndrome will take part in the first Australian clinical trial at The Alfred hospital, with the first dose administered on Thursday.

The rare syndrome is a disorder that occurs almost exclusively in females and first appears between the age of six to 18 months.

The disorder causes a loss of movement in hands, walking issues, seizures and intellectual disability.

"Rett syndrome is a devastating disease for patients and families, for which there are currently no treatments that improve the course of the disease. There is an urgent need for high quality, evidence-based treatments for Rett syndrome patients," Neurology Director Terry O'Brien said.

The professor said it was the only place in the country where there were neurology clinical trial wards, Professor O'Brien said.

The medication being trialled is currently used to treat Alzheimer's disease.

"The Australian Rett community is very excited to participate in this long awaited trial, which gives us hope for our children as well as helping to improve their quality of life," Rett Syndrome Association of Australia president Claude Buda said.

Treatment options currently use medication to address motor difficulties, breathing irregularities and controlling seizures.