A brother and sister who launched a campaign to encourage people to join the bone marrow register after their mother was diagnosed with leukemia say it has helped save five people’s lives.

Jonni and Caroline Berger organised the #Spit4Mum campaign after Sharon Berger, who lives in Kenton and was then 61, was diagnosed with leukemia on Boxing Day 2012.

Doctors said a transplant was her only chance of survival but that finding a donor could be difficult, as Jewish people were underrepresented on the Anthony Nolan bone marrow register.

Since the #Spit4Mum campaign, five people who joined the register have already gone on to donate their stem cells to people in need of a transplant.

Jonni Berger, 35, said: “Our family are thrilled that #Spit4Mum has been so successful and that in such a short space of time, five families, devastated by life-threatening illnesses, have been given a second chance in life, it just goes to show that this really works.”

Mrs Berger’s children held donor recruitment events across London, throughout the UK and worldwide to raise awareness of the need for more Jewish and ethnic minority bone marrow donors.

The #Spit4Mum campaign via Twitter and Facebook proved so successful the brother and sister helped increase the number of Jewish people on the Anthony Nolan register by 1,191 - more than ten times the previous year's total of 107.

They now hope that more of the people they inspired to join the register will be able to help future patients.

On average, only one in 1,200 people on the register are ever asked to donate - making the five new donors all the more impressive.

And five agonising months, a match was finally found for Sharon she underwent the crucial surgery, and today is making a good recovery.

Caroline Berger, 33, said: “It’s a real tribute to all of the supporters of #Spit4Mum that there is already such a successful legacy of the campaign which has once again beaten the odds and found five donors for patients in need.”