A bone marrow match has been found for a critically ill grandmother following a five month campaign by family and friends.

Sharon Berger, 61, was diagnosed with leukaemia just before Christmas last year when she was told she would need intensive chemotherapy and a bone marrow transplant.

But complications arose as Mrs Berger has a rare tissue type, and despite a full search on the global bone marrow donor registers no match could be found.

Determined to help their mother, Jonni Berger, 34, of Finchley and his sister Caroline Berger, 31, launched a global campaign to encourage people to sign up to Anthony Nolan Trust’s bone marrow register and Delete Blood Cancer.

Speaking to the Times Series Mr Berger said: “We decided social media was the best way of getting as many people as possible as quickly as possible to sign up.

“Although my mum has a Jewish heritage we were keen for anyone to sign up to help other people in a similar situation as well.”

Just when it seemed their luck was down, the family received the call they had been waiting for. A match has been found for Mrs Berger, who lives in Kenton, Harrow, but has been in Hammersmith Hospital since the beginning of last year.

Mr Berger said: “It’s like winning the lottery – it was a chance in a million. It’s amazing that a stranger could be able to her mum.

“Mum was thrilled but there’s still a long way to go. Hopefully she’ll have the transplant this week if she’s well enough.”

Mr Berger and his sister had launched their campaign via Twitter and Facebook using the hashtag #Spit4Mum which proved so successful they helped increase the number of Jewish people on the Anthony Nolan register by 1,191 compared to 107 in the same period last year.

The campaign also encouraged 800 people to join Delete Blood Cancer in just one week.

Mr Berger said: “We’ve been really cheered by the amount of support we’ve had. To have people we’ve never met trying to help mum has really given her strength.”

Ann O’Leary, Head of Register Development at Anthony Nolan, said: “We are absolutely delighted that Sharon has found a suitable bone marrow donor and we wish her all the best with her transplant. The spit4mum campaign has attracted a record number of Jewish people to join Anthony Nolan’s bone marrow register.

"This will help us to find suitable donors for more blood cancer patients in the future. This is one of the biggest patient appeals we have had and will have a huge impact on the register in terms of the number of potential Jewish donors.”