Increased availability of family donors for hematopoietic stem cell transplantation in a population with increased incidence of consanguinity.

The study was planned to determine the frequency of parental and non-sibling family donor transplants in our center and to investigate the rate of familial donor availability at two HLA-typing laboratories in Turkey. Among 203 patients who underwent hematopoietic stem cell transplantation (HSCT), 151 (74.4%) received stem cells from siblings, 48 (23.6%) from non-sibling family donors, two (1.0%) from unrelated cord blood, and two (1.0%) autologous transplantation. Of these 48 patients received stem cells from non-sibling family donors; donors were mothers for 26 (12.8%), fathers for 20 (9.9%), and aunts for two (1.0%). The rate of transplants from parental donors was 22.6% in this patient population with increased frequency of inherited diseases (58.1%). Among these 203 patients, there was consanguinity between parents in 60.6% of the patients. Of 833 subjects applying as donor candidates to HLA-typing laboratories, 527 (63.3%) had HLA 6/6 identical family donors. Among 527 full-matched donors, 479 (90.9%) were sibling, 21 (4.0%) were fathers, and 17 (3.2%) were mothers. The remaining 10 (1.9%) were other relatives. The results have shown that the unfavorable factor of consanguinity marriage may increase the availability of family donors for HSCT in particularly developing countries where large donor registries are lacking.