Asian Indian donor marrow registry: All India Institute of Medical Sciences experience.

A major limitation in hematopoietic stem cell transplantation (HSCT) is the availability of a genetically matched donor, particularly with respect to the human leukocyte antigens (HLA)-linked immune response genes located on chromosome 6 in humans. During the last 5 years, a total of 688 patients requiring HSCT underwent HLA testing in our department to identify a matched donor from their families. The sibship size ranged from 1 to > or =5 in all disease categories, except thalassemia major where the majority of patients had only 1 sibling. Family genotype analysis revealed that 39.3% of the total number of patients had an HLA-matched sibling and that families with sibship size of > or =4 had a higher probability (68.8%) compared with those with sibship size of < or =3 (29.7%). Because the Indian population is characterized by the presence of novel HLA alleles and unique haplotypes (HLA-A0211, B2707, A26-B08-DRB1*03), patients with rare HLA alleles have much less probability of finding an unrelated optimally matched donor than those with common HLA phenotypes. Smaller family size and unique HLA profile are limitations that can be overcome by developing unrelated volunteer marrow donor registries. The Asian Indian Donor Marrow Registry at our institute is regularly providing services to such patients.