A bone marrow donor has been found for critically ill Harrow grandmother Sharon Berger after a four month campaign by family and friends to find a match in the Jewish community.

Ms Berger suffers from Myelodysplastic Syndrome (MDS), a malfunction of the bone marrow in producing blood cells. “I have had no immune system for six years,” she said.

She has been in hospital since December, undergoing chemotherapy.

Her children Jonni and Caroline put in place a huge campaign, using the Twitter hashtag #Spit4Mum, encouraging Askenazi Jews to sign up to the Anthony Nolan bone marrow donor register.

Due to confidentiality rules nothing is known about the donor except that he or she is not a 100 per cent match.