1% for the BTGH, where 94% of donors were of Hispanic origin; 15.7% and 19.7%, respectively, NVP-BKM120 cell line for TWHT and TMH, where the vast majority of donors were Caucasian; and 3.8% for the SJMC, where

the majority of donors were Hispanic with a minority from the African American population. Information regarding the CCR5Δ32/Δ32 CBUs is summarized in Table 2. CCR5Δ32/Δ32 CBUs were obtained from three of the four hospitals (the BTGH, TWHT and TMH). Only one CCR5Δ32/Δ32 CBU in each case was obtained from the BTGH (0.15%) and TMH (1.6%) (Table 2). The majority of the CCR5Δ32/Δ32 CBUs (80%) were obtained from TWHT. If only the CCR5Δ32/Δ32 CBUs from TWHT are considered, then the frequency of finding an HIV-resistant CBU was 1.2%. The sample size for TMH was too small to determine whether the continued screening of CBUs from this hospital would yield frequencies similar to those for TWHT. As expected, most of the CCR5Δ32/Δ32 CBUs (8 of 10; 80%) were obtained from Caucasian parents. However, one CCR5Δ32/Δ32 CBU was collected from South Asian non-Hispanic and North American Hispanic parents,

while another ABT-737 nmr was obtained from parents who were both Hispanic. Both hospitals with a higher CCR5Δ32 allelic frequency (TWHT and TMH) had a ∼75% Caucasian population of parents with ∼25% of Hispanic origin. Although the BTGH and SJMC had higher populations of Caucasian parents (∼95 and 85%, respectively) they also had a higher percentage of Hispanics (∼95 and 80%, respectively). PIK3C2G All CBUs were typed for HLA A, B, C and DR alleles. Interestingly, two DR alleles, HLA-DR 0401 and HLA-DR 1101, were found three times in the CCR5Δ32/Δ32 CBUs identified (15%), whereas they were found in only 5% and 8%, respectively, of the entire population screened (Table 3). We found that the CCR5Δ32 allele was present at a significant

frequency in the CBUs we screened from the M. D. Anderson Cancer Center CB Bank. We found 10 CCR5Δ32/Δ32 CBUs in a total of 1538 CBUs screened, or 0.65% overall. Two of the CCR5Δ32/Δ32 CBUs (20%) did not pass quality control standards and cannot be used for transplantation. In comparison with previous studies on individuals of European descent [22], we noticed that the frequency of the CCR5Δ32 allele was slightly lower than expected in the CBUs we genotyped. This may be explained by the high rate of minority populations in Houston, a racially diverse city. Indeed, the intent of our CB Bank is to collect CBUs from diverse ethnic populations as a source of haematopoietic support for patients who need a stem cell transplant but lack an HLA-matched donor, which occurs most often in ethnic/racial minorities. Chen et al. [23] reported in a meeting abstract that StemCyte, an international cord blood (CB) bank, screened 10 488 CBUs for the CCR5Δ32 allele and identified 30 homozygotes and 754 heterozygotes. The frequency of homozygotes was 0.29%, whereas our survey yielded a 0.65% frequency in a smaller sample size.