Adelaide researchers will use cutting-edge "brain in a dish" technology to fight against the Sanfilippo syndrome, a rare and fatal type of childhood dementia.

A team from the South Australian Health and Medical Research Institute will lead the research into the rare Sanfilippo syndrome.

They will use "brain in a dish" technology to find out if existing drugs can be repurposed to help sufferers of the genetic condition.

The Sanfilippo syndrome is a degenerative condition that causes fatal brain damage.

Following an initial period of normal development, children will experience declining brain function with hyperactive behaviour, progressive dementia and loss of mobility.

Life-expectancy for sufferers is between 12 and 20 years.

Associate Professor Kim Hemsley said the "brains in dishes" will allow researchers to fast-track the testing of a range of drugs that have already been deemed safe for humans.

They will reverse engineer patients' skin cells into stem cells before developing them into neural cells, creating an individualised representation of the brain.

"Each of us reacts differently to a given medication, so by using a patient's own cells we can create a targeted, personalised treatment plan," Professor Hemsley said.

The South Australian government has contributed $2 million to the research, with a further $500,000 coming from the Sanfilippo Children's Foundation.

Teams from the Adelaide Women's and Children's Hopsital and the University of Adelaide will also help in the study.