摘要:

AbstractA computer‐simulation method is presented for determining and correcting for the effect of maximizing the lod score over disease definitions, penetrance values, and perhaps other model parameters. The method consists of simulating the complete analysis using marker genotypes randomly generated under the assumption of free recombination. It is applicable as a “post‐treatment” to linkage analyses of any trait with an uncertain mode of inheritance and/or disease definition. When the method is applied to a linkage analysis of schizophrenia versus chromosome 5 markers, we find that, in this specific case, theP‐value associated with a maximum lod score of 3 is equal to 0.0003. We also find that a lod score of 3.0 should be “deflated” by approximately 0.3 to 1 units, and, by tentative extrapolation, the observed lod score of 6.5 should be “deflated” by

ISSN:0741-0395    

DOI:10.1002/gepi.1370070402

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe significance of a lod score value of 3 is very difficult to assess in linkage studies between a genetic marker and a complex disease. One reason is that multiple tests may have been performed, voluntarily or otherwise. For the same disease, linkage may be tested by different laboratories with several markers under various genetic models and diagnostic schemes for the disease. In such a case, we show that the probability of getting a lod score value of 3 under independent transmission of the disease and the marker may be not negligible.

ISSN:0741-0395    

DOI:10.1002/gepi.1370070403

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe relationships between serum lipids, blood pressures, anthropometric traits, age, and ischemic changes of the electrocardiogram (ECG) in the North Khanty population were studied. To this end, eight morphophysiological variables—presumably risk factors for ischemic heart disease—have been subjected to a principal components analysis. Two principal components were extracted. The first revealed age dependency of the traits not associated with ischemic changes of myocardium in both sexes. A comparative analysis of the second component has shown that the chosen traits correlated with ischemic heart disease in males but not in females. Interpretation is given of the components obtai

ISSN:0741-0395    

DOI:10.1002/gepi.1370070404

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

年代:1990

数据来源: WILEY

摘要:

AbstractDietary intervention studies (from a low polyunsaturated/saturated fatty acid ratio P/S diet to a high P/S diet), carried out on a group of healthy individuals from North Karelia, Eastern Finland between 1981–1984, provided evidence that there may be a genetic component contributing to variation in response to dietary change. We have resampled blood from 107 individuals involved in the original studies and used Restriction Fragment Length Polymorphisms (RFLPs) to study the genetic contribution of variation at a number of candidate gene loci to the response to dietary change. The genes investigated in this study were the apolipoprotein (apo) genes: apo B, apo AII, apo E (protein polymorphism), apo AI‐CIII‐AIV gene cluster, and the LDL‐receptor gene.On the basal diet the major effect of genotype on lipid traits was due to variation at the apo E gene locus; this protein polymorphism explained 14.6% of the phenotypic variance in LDL cholesterol levels and 12.7% of the phenotypic variance in total cholesterol levels. When switched to low fat high P/S diet, these effects of variation at the apo E gene locus on the phenotypic variation of LDL and total cholesterol levels disappeared. The major effect on the response to dietary change, Δ, was seen on the difference in apo AI levels mediated by variation at the apo B gene locus (MspI RFLP) explaining 6.3% of the phenotypic variance in apo AI change. For the RFLPs of the apo AI‐CII‐AIV gene cluster, small but not significant differences on Δ were found. Our results indicate that within the limits of the candidate genes studied, the major effects in response to dietary change was on apo AI levels mediated through variation at the apo

ISSN:0741-0395    

DOI:10.1002/gepi.1370070405

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

年代:1990

数据来源: WILEY

摘要:

AbstractSelf‐reported histories of hay fever and asthma were obtained from 3,808 pairs of adult twins 18 years and over registered with the Australian National Health Medical Research Council Twin Registry (1232 MZF, 567 MZM, 751 DZF, 352 DZM, 906 DZO). The prevalence of hay fever and asthma was 0.32 and 0.13, respectively, with little variation with zygosity, sex, and age. The associations between twin pairs for these two traits were analysed, under the assumption of constant prevalences, as a special case of a log‐linear model for binary traits in pedigrees using the statistical package GLIM. The model assumption that there are no secondor higher‐order interactions was tested in the 2 × 2 × 2 × 2 table of twin by disease outcomes without revealing strong evidence of departure, even in this large data set. The log‐linear modelling showed that only three first‐order interactions, namely 1) between hay fever in a twin pair, 2) asthma in a twin pair, and 3) hay fever and asthma in the same twin, were necessary to describe the data. The first two interaction terms were significantly larger in identical pairs; the third was independent of zygosity. Under this parsimonious model, there was a significant difference between identical and fraternal pairs in marginal correlation, both in asthma and hay fever, and in the cross‐correlation between hay fever in one twin and asthma in the other. This suggests that genetic factors are implicated in both hay fever and asthma and that some of these genetic factors are common (at least among a subgroup of individuals)

ISSN:0741-0395    

DOI:10.1002/gepi.1370070406

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

年代:1990

数据来源: WILEY

摘要:

AbstractFamily histories of male patients with histologically confirmed malignant gliomas were compared to family histories of controls (wives). Included were 77 case families with 892 relatives and 77 control families with 719 relatives. Cases had significantly more siblings than controls (P= 0.02), although cases were not preferentially the oldest or the youngest sibs. Odds ratios of two or more were found for mental retardation, Parkinson's disease, and meningitis for the relatives of cases versus controls, but none were statistically significant. The excesses of Parkinson's disease and meningitis were explained by the family of one particularly interesting case containing three relatives with meningitis and two relatives with Parkinson's disease. Noteworthy age‐adjusted odds ratios for cancer among relatives of cases compared to relatives of controls were 1.6 (95% confidence interval (CI) = 1.0–2.3) for cancer of any site, 2.4 (95% CI = 0.8–6.1) for breast cancer, and 4.0 (95% CI = 0.6–10.7) for lung cancer. Only the odds ratio for cancer of any site was statistically significant. Overall, 6 of 77 (8%) of cases came from families that included two or more relatives with breast or lung cancer in addition to the proband with malignant glioma. These three cancer sites may form familial clusters worthy of further evaluation in future studies by pedigree and genetic linkage a

ISSN:0741-0395    

DOI:10.1002/gepi.1370070407

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

年代:1990

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370070408

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

年代:1990

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370070409

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

年代:1990

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370070401

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

年代:1990

数据来源: WILEY