SummaryGermline mutations in patients with hemophilia B generally have arisen within the past 150 years. Evidence suggests that these germline mutations generally result from endogenous processes. However, a unique pattern would be expected if a population were exposed to a physiologically important germline mutagen since mutagens generally produce characteristic patterns, or “fingerprints”, of mutation. To determine the pattern of mutation in Mexican Hispanics, the regions of likely functional significance in the factor IX gene were screened by di-deoxy fingerprinting (ddF) in 31 families with hemophilia B. Mutations were found in 30 of these families. Haplotype analysis was performed on individuals with identical mutations to help distinguish independent, recurrent mutations from founder effects. Analysis of these 30 mutations, along with 7 mutations reported previously in Mexican Hispanic families, reveals a pattern of independent mutation that is similar to the pattern of mutation observed in 127 U. S. Caucasian families (p = 0.89). These results may reflect either an underlying pattern of germline mutation due to endogenous processes or the presence of an ubiquitous mutagen. Further analyses of the recurrent mutations revealed that two mutations, T296M and R248Q, accounted for 19% of the mutations found in the Mexicans. Haplotype data suggest that the multiple occurrences of T296M and R248Q are associated with founder effects and that screening for these mutations may allow rapid mutation detection and carrier diagnosis in a significant minority of Mexican families with hemophilia B. These two mutations also are associated with founder effects in the U. S. Caucasian population. However, the haplotypes are different in these two populations, indicating independent origins. The occurrence of identical founder mutations in distinct populations provides evidence for the previous hypothesis that the number of different mutations giving rise to mild or borderline mild/moderate hemophilia B is small compared to deleterious mutations causing more severe disease.
Early thrombotic events and preemptive systemic anticoagulation following splenectomy for myelofibrosis
AbstractThis study examines the long‐term OS of relapsed AML patients who were enrolled to 9 successive ECOG‐ACRIN trials for newly diagnosed AML, during 1984‐2008. The objectives were to examine whether there is a trend of improvement in the survival of relapsed AML patients in the more recent studies and to search for prognostic factors that are associated with long‐term OS after relapse. A total of 3012 patients were enrolled, 1779 (59.1%) achieved CR1 and of these, 58.9% relapsed. The median follow‐up was 9.7 years. The median OS from relapse was 0.5 years and the 5‐year OS was 10 (±1)%. These results were similar even for the most recent studies. A multivariate model showed that age, cytogenetics at diagnosis, duration of CR1 and undergoing allogeneic transplantation were significantly associated with OS from relapse. Even among patients who relapsed with better prognostic factors; age < 40 and CR1 > 12 months, there was no significant OS difference between the studies. In conclusion, this large cohort appears to confirm that the survival of AML patients postrelapse continues to be dismal and has not improved during the past quarter of a century.
The Utilization of Chromosomal Microarray Technologies for Hematologic Neoplasms