Ava Stark, from Lochgelly in Fife, has a rare blood condition and needs a stem cell transplant or she will die.
Her desperate mum Marie, 33, made a public plea earlier this year, urging people from around the world to get tested as they desperately try to find a life-saving match.
It is the second time a matching donor has been unable to donate.
Blood cancer charity DKMS is now asking organisations in Scotland to hold donor recruitment events at their workplaces.
Almost 50,000 people have registered as potential blood stem cell donors through the DKMS website after the terrible news that the person who was due to donate some of their blood stem cells to help save the life of Ava was now unable to donate for medical reasons.
When Ava was diagnosed a search of the register worldwide - which has about 25 million people on it - was carried out, and one suitable candidate was found, but the donor pulled out.
The second potential donor has now been ruled out for medical reasons.
Ashlie Caddick, donor recruitment manager at the charity, said: “Although it is great that so many have registered to help Ava and all those in need of a lifesaving blood stem cell donation, it isn’t enough. We need many, many more people to register.
“We particularly want to give those who might not want to register online the chance to register as a potential blood stem cell donor at an event.”
Anyone between the ages of 17 and 55 and in general good health can register as a donor.
It takes two minutes to swab cheeks and this can be done during a break in the working day.
DKMS’s workplace donor registration events are an easy and convenient way for employees to find out more and become a potential blood stem cell donor.
To find out how you can find support the charity by holding a donor recruitment event in your workplace, please contact Ashlie Caddick at [email protected] or on 020 8747 5635.
Every 20 minutes, someone in the UK is diagnosed with a blood cancer like leukaemia, lymphoma or myeloma (Cancer Research UK, 2014).
Aound 2,000 people in the UK cannot find a donor within their family.
There are over one million people registered as potential blood stem cell donors in the UK, who are registered with DKMS, Anthony Nolan and NHSBT.
DKMS is a global not-for-profit that started in Germany in 1991 around one family’s search for a donor.
Dr. Peter Harf founded DKMS in honour of his wife Mechtild, who had sadly lost her battle with blood cancer. Peter promised his wife to help every blood cancer patient searching for a matching donor.
Today DKMS operates in Germany, USA, Poland, Spain and the UK.