The mysterious potentially life-threatening disease of a young woman from NSW - who had been regularly requiring medical care for more than a decade - and, its cure, has been successfully identified by Australian doctors.

The report of the case has been released by the Queensland Institute of Medical Research (QIMR). 

Katie Pulling was discovered to have a previously identified, and still unnamed, disorder in which her immune system is not working as it normally would.

Head of QIMR's Immunohaemotology Laboratory, Dr Maher Gandhi says, I haven't got a name for it other than 'T-cell signalling defect' of which I assume that are quite a few different types.

No recorded case like Katie's can be found in the medical literature, and Dr Gandhi believes they're just looking at the tip of the iceberg.

Ms Pulling, now 23 was successfully treated through the use of experimental bone marrow transplant procedure using her sister's donated stem cells.

The procedure was carried out at the Royal Brisbane and Women's Hospital.

The transplant is usually used to treat leukaemia patients as it functions to jump-start the the immune system.

The radical approach was chosen by the doctors when Ms Pulling became critically ill -triggered by the virus that normally causes glandular fever.

Doctors realized her immune system and its signalling pathways were defective following an episode of full-blown infectious mononucleosis - after years of severe complications experienced from generally common infections.

Dr Gandhi says, The transplant was dangerous but the results were amazing.

The defect in Katie's immune cells has been fixed, and to our knowledge, this is first time this disorder has been reported.

The doctors are hopeful that this treatment can be used for anyone who exhibit the same symptoms and no success with past treatments.