Fight with leukemia reveals marrow-match difficulties

People of mixed race face tougher odds of finding a suitable donor


Staff Writer

Last January, British national Aidan O’Connor, 46, purchased an old townhouse in the heart of historic Sasayama, a town known for its wild boar cuisine and large chestnuts.

Just before the move, O’Connor visited his doctor in Ashiya, Hyogo Prefecture, to inform him that after three years there, he, his wife, and his young daughter and son were moving to the countryside.

The doctor suggested one last routine checkup, and that’s when O’Connor’s life changed forever.

“I was referred to a hospital in Ashiya after the initial tests. More tests revealed I had leukemia. The doctors said I needed to take six months off of work to undergo intensive chemotherapy,” he said.

The news got worse. O’Connor was discovered to have a pre-existing condition called myelodysplastic syndrome. This meant that while the chemotherapy sent the leukemia into remission, it would not be a long-term cure.

Initially told a bone marrow transplant was an option, Aidan learned to his shock at a more specialized hospital that a transplant was now a necessity and that he could die within a year if he didn’t get one.

Thus began a long, difficult and costly journey to find a donor.

No siblings proved to be suitable and a Japanese bone marrow donor bank was unable to find a match. O’Connor was forced to look overseas, to the United States, as Japan has no direct exchange with European donor banks.

O’Connor, a part-time university lecturer at several different schools and well-known among long-term Kansai expatriates as a specialist writer on Japanese food for local English-language media, eventually discovered the total cost to find an overseas donor was ¥3.5 million. Worse, his national health insurance covered only the costs of a domestic donor, which meant he had to come up with the funds himself.

Fortunately, potential donors have been identified. He is now in the process of raising money for the transplant and rehabilitation. But the experience has caused him concern about his children.

“Thankfully, leukemia is not hereditary. But I’m a Caucasian and Irish, so the pool of potential donor matches is much greater than it would be for my children, who are Japanese-Caucasian,” he said.

Shin Ito, director of the Los Angeles-based A3M Asians for Miracle Marrow Matches, told The Japan Times in an email that O’Connor’s concerns about his children are justified.

“There are over 300,000 potential donors who are of multiple race in the National Marrow Donor Program’s total bank of 9 million registrants. The number of potential donors who are Japanese-Caucasian is just a fraction of the 300,000,” Ito said.

Ito noted that anyone who is part Asian and part Caucasian might be a potential donor for O’Connor’s children, but someone who is half Japanese and half Caucasian is more ideal.

“People of the same race generally share more genetic material. It’s quite common for someone who is Chinese or Korean to donate to a Japanese. However a mixed-race patient needs to find a similar combination, which makes it more challenging,” Ito said.

Junko Chiba, a spokeswoman for the Japan Marrow Donor Program agrees with Ito.

“It can be difficult for people of mixed-race parentage to find an ideal match if they need a bone marrow transplant,” she said.

Ito says there is good news and bad news for children with a Japanese and Caucasian parent, at least in the U.S.

“There are probably more mixed-race combinations of Japanese and Caucasian, compared to Caucasians and other Asian ethnic backgrounds. When A3M first started over 20 years ago, our focus was on the Japanese-American community, and mixed-race marriages occurred a little earlier with Japanese-Americans than with some other groups.

However, the Japanese-American community is smaller than some other Asian communities, so the pool (of potential donor matches) is also smaller,” he said.

As of the beginning of this year, the Japan Marrow Bank had marrow contributions from 400,972 people. Chiba said there are no statistics on how many donors were either of a separate nationality or of mixed-race parentage.

But with the number of international marriages in Japan on the rise, the need for bone marrow donors of mixed race is likely to grow. Chiba urges everyone to consider donating bone marrow, nowadays a fairly quick and painless procedure.

As for O’Connor, thanks to Japan’s formal exchange with America’s donor bank, he has found a very good match and will likely receive the transplant this spring. It’s still a risky procedure. But he’s optimistic, although he especially encourages those of mixed race to become bone marrow donors.

“It would be nice to think that anybody, regardless of race, who needs a bone marrow transplant has a good chance of finding a donor match in Japan,” he said.

For more information on Aidan O’Connor’s case, visit For information on the Japan Marrow Donor Program, visit For more information on A3M, visit