Anticipation in familial hematologic malignancies.

We describe a collection of 11 families with ≥ 2 generations of family members whose condition has been diagnosed as a hematologic malignancy. In 9 of these families there was a significant decrease in age at diagnosis in each subsequent generation (anticipation). The mean age at diagnosis in the first generation was 67.8 years, 57.1 years in the second, and 41.8 years in the third (P < .0002). This was confirmed in both direct parent-offspring pairs with a mean reduction of 19 years in the age at diagnosis (P = .0087) and when the analysis was repeated only including cases of mature B-cell neoplasm (P = .0007). We believe that these families provide further insight into the nature of the underlying genetic mechanism of predisposition in these families.

Linkage to 10q22 for maximum intraocular pressure and 1p32 for maximum cup-to-disc ratio in an extended primary open-angle glaucoma pedigree.

PURPOSE: The purpose of this study was to identify genetic contributions to primary open-angle glaucoma (POAG) through investigations of two quantitative components of the POAG phenotype. METHODS: Genome-wide multipoint variance-components linkage analyses of maximum recorded intraocular pressure (IOP) and maximum vertical cup-to-disc ratio were conducted on data from a single, large Australian POAG pedigree that has been found to segregate the myocilin Q368X mutation in some individuals. RESULTS: Multipoint linkage analysis of maximum recorded IOP produced a peak LOD score of 3.3 (P = 0.00015) near marker D10S537 on 10q22, whereas the maximum cup-to-disc ratio produced a peak LOD score of 2.3 (P = 0.00056) near markers D1S197 to D1S220 on 1p32. Inclusion of the myocilin Q368X mutation as a covariate provided evidence of an interaction between this mutation and the IOP and cup-to-disc ratio loci. CONCLUSIONS: Significant linkage has been identified for maximum IOP and suggestive linkage for vertical cup-to-disc ratio. Identification of genes contributing to the variance of these traits will enhance understanding of the pathophysiology of POAG as a whole.