摘要:

AbstractThe frequency of restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene, detected byXbaI andEcoRI, and their influence on serum lipids and apolipoproteins were studied in healthy Chinese of both sexes in Singapore. A total of 221 subjects (150 males, 71 females) were investigated for theXbaI and 159 subjects for theEcoRI polymorphisms, while serum lipids and apolipoprotein levels were available for 196 subjects. The frequency of theX2allele was found to be significantly lower in the Chinese than that reported in Caucasians from the United Kingdom (0.09 vs. 0.51,P<0.001). The haplotype frequencies were also significantly different between the Chinese and Caucasians with a higher frequency ofXlRlin the former compared to the latter (0.85 vs. 0.34,P<0.0001). The distribution of RFLP genotypes at both of the restriction sites was atHardy‐Weinbergequilibrium in all groups. The influence of the apo B RFLPs on serum lipids and apolipoprotein levels (apo AI, AII, and B) was studied by both residual and multiple regression analyses considering age, sex, body mass index (BMI), and genotypes as independent variables in all possible combinations. No association was observed between the apo B genotypes and serum lipids or apolipoprotein levels except for high density lipoprotein cholesterol (HDLC), apo AI and AII, with theX2being associated with significantly lower levels of HDLC as well as apo AI and AII, the effect being stronger in males. These data raise the possibility that the mechanism of reported association between apo B polymorphism and coronary artery disease may be through effects on HDLC. © 1992 Wiley‐Liss,

ISSN:0741-0395    

DOI:10.1002/gepi.1370090103

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

年代:1992

数据来源: WILEY

摘要:

AbstractSystolic (SBP) and diastolic (DBP) blood pressures were measured in a health screening of the adult population in Nord‐Trøndelag, Norway. Correlations were computed for 23,936 pairs of spouses, 43,586 pairs of parent and offspring, 19, 151 pairs of siblings, 1,251 pairs of grandparents‐grandchildren, 1,146 pairs of biological uncles/aunts‐nephews/nieces (avuncular), 801 non‐biological avuncular pairs, 169 pairs of same‐sex twins, and smaller groups of other types of relationships. Spouse correlations of 0.08 and 0.09 were approximately constant or slightly decreasing with marital duration. The correlation values for SBP and DBP were approximately 0.16 for parents‐offspring, 0.19 to 0.23 for same‐sex siblings with similar values for DZ twins, 0.19 and 0.16 for opposite‐sex siblings, 0.52 and 0.43 for MZ twins, and close to zero for most of the second‐order relationships. Genetic additive variance was estimated at 0.29 and genetic dominance variance at 0.18 with the best model for SBP. The corresponding estimates from the best models for DBP were 0.29 or lower and 0.22 or lower, the sum not exceeding 0.35. There was evidence of a moderate effect of environmental factors shared by same‐sex siblings and twins (for DBP), but no cultural transmission, and whether or not adult relatives live together does not affect familial resemblance for BP. The data did not permit a very precise resolution of the relative magnitude of genetic dominance and sibling effects. The correlation structure did not show sex‐specific genetic effects.

ISSN:0741-0395    

DOI:10.1002/gepi.1370090104

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

年代:1992

数据来源: WILEY

摘要:

AbstractStimulated by a large pedigree with a cochlear form of deafness, for which we considered a two‐locus mitochondrial and nuclear gene model, we have extended the classic methods of segregation analysis to these classes of two‐locus disorders. Based on the unique maternal transmission pattern of the mitochondria, we demonstrate that utilization of the maternal line pedigree allows us to simplify the various two‐locus mitochondrial models to ‘one nuclear locus’ models. Classifying the nuclear families into different independent groups by the mother's phenotypes allows us to estimate the nuclear gene frequency in one group and to use this estimate as the expected value to test the fitness of the model on the other group. In addition, if we restrict the analysis to specific subsets of the mating type(s), we can also test the model on specific groups of nuclear families without estimating the gene frequency. Goodness‐of‐fit tests can be performed on pooled sibship data as well as individual sibship data. These methods of analysis should assume increasing importance as more disorders with features of mitochondrial inheritance are identified. © 1992 W

ISSN:0741-0395    

DOI:10.1002/gepi.1370090105

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

年代:1992

数据来源: WILEY

摘要:

AbstractWhen a disease is controlled by two or more mendelian loci acting epistatically, it can be modeled in a linkage analysis as a single‐locus mendelian disease with reduced penetrance. However, the reliability of such an approximation has not yet been demonstrated. This study evaluates the adequacy of such single‐locus approximations, when the disease under investigation is determined by two loci, one of which is tightly linked to a genetic marker.A wide range of two‐locus models were simulated, and analyzed under both the correct two‐locus model and under a single‐locus approximation to that model. In general, the single‐locus approximations yielded lod scores very close to the correct ones, but estimates of θ tended to be upwardly biased. We conclude that a single‐locus linkage analysis will, in general, provided an excellent approximation to a correct (two‐locus) linkage analysis of epistatic two‐locus diseases. This enables researchers to continue to use single‐locus linkage analyses when two‐locus disease transmission is a possibility, and it validates linkage findings already obtained under single‐locus analysis, even if the disease under in vestigation proves ultimately to be governed by two mendelian loci. We also examine alternative methods for obtaining parameter estimates for the single‐locus approximations, and we discuss both generalizations and limitations of our findin

ISSN:0741-0395    

DOI:10.1002/gepi.1370090106

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

年代:1992

数据来源: WILEY

摘要:

AbstractLinkage analysis under the two‐locus model and the admixture model was compared on pedigree data for a common disease simulated under a model of genetic heterogeneity. The ascertainment of families was designed so that the samples had a large proportion of families segregating for both disease loci. The two‐locus linkage analysis model did not demonstrate increased power of detecting linkage or more accurate estimates of the recombination fraction, θ than did the admixture model linkage analysis. When a sample was purposely chosen so thatallof the families were segregating for both loci, then the two‐locus lod score analysis was better. However, the increased power depended on assuming the correct gene frequency for the linked locus. It can be concluded that under the conditions of genetic heterogeneity examined here, testing for linkage under the admixture model is the preferred method of analysis. However, this is not a general conclusion that can apply to all two‐locus disease models. Published 1992 by Wiley

ISSN:0741-0395    

DOI:10.1002/gepi.1370090107

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

年代:1992

数据来源: WILEY

摘要:

AbstractPaternity exclusions are known to be common in Western countries and are yet neglected in segregation analysis because it is almost impossible to check it systematically on a large family sample. We had the opportunity of observing the sensitivity of segregation analysis parameters to a paternity exclusion in analyzing 34 families for a simple Mendelian trait, the acetylator phenotype. We found that only one family, with proven paternity exclusion, was responsible for a strong rejection of Mendelian transmission probabilities (P≪0.001). © 1992 Wiley‐Liss,

ISSN:0741-0395    

DOI:10.1002/gepi.1370090108

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

年代:1992

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370090102

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

年代:1992

数据来源: WILEY