摘要:

AbstractComputer‐based simulation has been an important method in human linkage analysis for a long time. Typically, such analyses have been performed by simulating a set of linked markers according to the intermarker recombination fractions, under the assumption of no genetic interference. A novel approach is proposed in which such simulations can be performed using chromosome‐based methods, rather than traditional recombination fraction‐based methods. We propose simulating pedigree data using a crossover formation (CF) process to generate the number of crossovers and their locations in Morgans along the entire length of a chromosome. By this method, one can generate simulated multilocus data for any number of loci on a chromosome much more efficiently than with the currently available methods like those used in the SLINK or SIMLINK programs. Further, interference can be incorporated directly in this method, which is not possible with existing packages. © 1993 Wiley‐L

ISSN:0741-0395    

DOI:10.1002/gepi.1370100402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn improved sib‐pair test for linkage is introduced which is superior to the previously proposed tests. The test is derived from the standard chi‐squared goodness of fit statistic by restricting the alternative hypothesis to the genetically possible. Critical values are given and exact power comparisons are made with the previously proposed tests. The new test is shown to be more powerful for finite samples as well as being asymptotically uniformly most powerful. © 1993 Wiley‐Lis

ISSN:0741-0395    

DOI:10.1002/gepi.1370100403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe aggregation of colon, endometrial, ovarian, and possibly breast cancers in families has been described as a “cancer family syndrome” (now called Lynch syndrome II). To determine if the familial clustering of these malignancies was more common in women with cancer than without, we analyzed data from the Iowa Women's Health Study (IWHS), a population‐based sample of 41,837 women aged 55–69 years. Self‐reported information was collected on history of colon, uterine, ovarian, and breast cancers in female first‐degree relatives. A family history of cancer of the breast (odds ratio [OR] = 1.4), colon (OR = 1.3), and uterus (OR = 1.3), but not ovary (OR = 1.2), was significantly more common among women with a personal history of any of these four cancers (allP<0.05); the pattern of the ORs suggested strongly that the clustering tended to be site‐specific. Age‐adjusted relative risks (RR) of incident colon cancer over 5 years of follow‐up (N = 237) were calculated with regard to family history. Colon cancer incidence was increased among women with a family history of breast (RR = l.3), uterine (RR = 1.4), colon (RR = l.5), and ovarian (RR = 1.3) cancers, although none of the risk estimates achieved statistical significance. RR was, however, significantly related to the number of different cancer sites reported among family members (Ptrend= 0.008). These data on a representative sample of postmenopausal women suggest that family histories of colon, breast, uterine, and ovarian cancers are associated with an increased risk of cancer at the same site, but provide little support for the hypothesis that Lynch syndrome II is a non‐random occurrence. ©

ISSN:0741-0395    

DOI:10.1002/gepi.1370100404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe objective of this study was to validate reports on the bilaterality status of breast cancer in first‐degree relatives of women with a strong family history of the disease; i.e., women with 1) two first‐degree relatives who have, or have had, breast cancer; 2) one first‐ and one second‐degree affected relative; or 3) one first‐degree relative with diagnosis of breast cancer before the age of 50 years and/or bilateral breast cancer. We were able to obtain hospital records for 94 affected relatives of 83 patients who agreed to participate in the study. The accounts of these women were compared to the bilaterality status indicated in the hospital records of the affected relatives. Inconsistencies that might have been attributed to incomplete medical records were resolved through personal interviews with the participants, and when indicated, with other family members or the physician of the affected relative. Overall, 89.4% (84/94) of the reports validated in this manner were correct. Participants who reportedunilateralbreast cancer in a first‐degree relative were correct 94.4% (68/72) of the time. Similarly, 94.0% (47/50) of the accounts concerning affectedlivingrelatives were accurate, regardless of whether the participant had indicated unilateral or bilateral disease. However, participants who reported bilateral breast cancer in a deceased relative were accurate only 61.5% (8/13) of the time. Incorrect reports were associated with misunderstanding of medical terminology, especially if the participant was young at the time of the diagnosis of her relative. © 1993 Wil

ISSN:0741-0395    

DOI:10.1002/gepi.1370100405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA sample enriched for familial combined hyperlipidemia (FCHL) was examined for evidence of an association between genotype at an apolipoprotein B (apoB) elevating locus defined by complex segregation analysis and FCHL. Complex segregation analysis detected a locus with a large effect on plasma apoB levels and was used to compute the most probable genotype of family members. None of the 35 normolipidemic adults carried a copy of the allele associated with elevated apoB levels, yet 58% of the 109 adults with FCHL carried 1 (29%) or 2 (28%) copies. Two of 28 (7%) normal children had 1 copy of this allele and none had 2 copies, while 88 of 182 (48%) children with FCHL had 1 (26%) or 2 (22%) copies. Further, 4l of 48 (85%) individuals classified as having hyperapobetalipoproteinemia did not carry a copy of this “elevated apoB” allele. Therefore, the presence of the allele associated with elevation of apoB level is highly predictive of FCHL and this association cannot be explained solely by the presence of elevated apoB levels in FCHL, suggesting that the locus controlling apoB levels may play an etiologic role in FCHL. © 1993 Wiley‐Lis

ISSN:0741-0395    

DOI:10.1002/gepi.1370100406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370100407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370100401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY