The Australian Rett Syndrome Study and InterRett are directed by Dr Helen Leonard at the Telethon Institute for Child Health Research, Australia.

The Australian Rett Syndrome Study is a population-based study which includes almost all children and adults with Rett syndrome born since 1976 in Australia. Information is collected by questionnaire from families and doctors including those who manage the Rett syndrome clinics in Sydney, Melbourne, Brisbane and Perth.

InterRett is an international study which collects information on children and adults with Rett syndrome from families and doctors across the world. InterRett also collaborates with researchers in Europe and the United States for particular projects.