For some, steep odds to find a bone marrow match
http://www.bostonglobe.com/lifestyle/health-wellness/2013/08/20/awaiting-transplant-cancer-patient-chances-depend-her-korean-heritage/oXksbeVUYTNez8KcaS6trM/story.html
Now, the 40-year-old’s Korean heritage has suddenly become central to
her life in a way she never expected. After being diagnosed with acute
myeloid leukemia in July, Manocchio-Putney faces a disturbing reality
shared with many minorities in the United States — getting a bone marrow
donation to save her life will be much harder for her than it would be
for one of her two Caucasian siblings.
While 93 percent of Caucasians are able to find a match among the
10.5 million potential donors registered nationwide, the likelihood of
finding a match is lower for Asian-Americans — 73 percent — said Chris
Mulcahy, northeast district supervisor for Be the Match, which oversees
marrow drives and registries.
And it’s even more difficult for mixed-race individuals,
African-Americans, and some subsets of Asian-Americans, particularly
South Asians, to find a match, said Dr. Joseph Antin, chief of stem cell
transplantation at Dana-Farber Cancer Institute.
Bone marrow donors must have similar genetic history to recipients,
Antin said. Though race has no genetic basis, the genes that determine
the success of transplanted cells, called human leukocyte antigens,
correlate with individuals’ ethnic backgrounds.
Humans developed distinct resistances to pathogens depending on what
diseases proliferated in which parts of the world, meaning different
ethnic groups evolved with different HLA genes.
That genetic diversity in human leukocyte antigens makes it hard for
everyone to find a bone marrow match. But it’s even tougher for people
of Asian and African descent, because the more diverse an individual’s
evolutionary history is, the harder it becomes to find a match. Since
populations in Africa and Asia developed in the face of some of the most
diverse conditions, many of its people have unique genetic types.
But sometimes, in cases like Manocchio-Putney’s, one individual’s
case can generate enough momentum to expand the registry. For many
years, Antin said, it was nearly impossible to find bone marrow matches
for Ashkenazi Jews, whose families came from Europe. When one such Jew
got sick, the community mobilized, and now many are registered as
potential donors.
