Staff from the Western Australian Institute for Medical Research (WAIMR), the Telethon Institute for Child Health Research (TICHR) and the Neurogenetics and Forensic laboratories within PathWest, combined to establish that the little girl had died from the devastating neurological disorder, Rett Syndrome.
The group was able to make the diagnosis after carrying out a gene test on DNA extracted from the baby tooth.
A paper outlining the effort has just been published in the international medical journal, The Lancet.
Professor David Ravine, from WAIMR's Laboratory for Molecular Genetics and Dr Helen Leonard, coordinator of the Australian Rett Syndrome Study at the TICHR in Perth, said confirming the diagnosis had finally laid to rest many of the family's fears.
"Despite intensive investigation, the little girl's condition went undiagnosed by doctors all through her life, so the fact that the cause of her illness and death was finally pinpointed, gave the family the information they needed to understand what had happened," said Professor Ravine.
The mother contacted Dr Helen Leonard after coming across the Australian Rett Syndrome Study website and remembering that an occupational therapist had once suggested that her daughter might have this disorder.
Dr Leonard said that the confirmation of a definite diagnosis had erased years of worry for the family.
"Not knowing what was causing their daughter's illness, her parents began to wonder if they were somehow responsible," she said.
"They were worried their daughter's condition may be linked to a vaccination she'd had just before her health deteriorated.
"On top of that, her father felt guilty about the circumstance of a fall she'd had at 17 months.
"So to know, after such a
Contact: Natalie Papadopoulos