摘要:

AbstractSex‐steroid hormones are a major determinant of the risk of breast cancer. We evaluated the relationship between obesity and endogenous estrogen levels in 79 healthy, postmenopausal women. Thirty‐nine of the women were siblings of patients with postmenopausal‐onset breast cancer; the remaining women were age matched (± 10 yr) controls. Our hypothesis was that the siblings of the breast cancer patients would weigh more and that this excess weight would lead to higher serum estrone levels. The choice of unaffected family members of breast cancer patients reduces the concern that results may have been influenced by the cancer rather than antecedent to its development. Our findings demonstrated a statistically significant excess estrone level in the siblings compared to the controls (58.9 vs 47.8 pg/ml, P=0.005). The siblings weighed 4.3 kg more than the controls. Matched pairs analysis (sibling—control), adjusting for weight, also showed significant differences in serum estrone levels. These differences were observed despite comparability in dietary intake, medication use, and personal medical history. These findings represent the first time that higher estrogen levels have been measured in siblings of postmenopausal breast cancer patients. This observation may represent an important link in our understanding of the relationship between genetic and environmental risk factors of breast cancer. One approach to subsequent genetic studies of breast cancer may be to focus on the possible biological determinants such as sex‐steroid hormone level receptors, oncogenes, and gene products and not on the “familial aggregation” of

ISSN:0741-0395    

DOI:10.1002/gepi.1370040402

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

年代:1987

数据来源: WILEY

摘要:

AbstractA discriminant analysis has been applied to physical and laboratory data on a series of 37 patients with rheumatoid arthritis (RA). Good discrimination was found between RA when it was associated with organ‐specific autoimmune phenomena and when it was not. When data from other members of the families was included there was consistently better discrimination than when using data from the patients alone. The results suggest that future studies of classification of variable diseases should include study of relative

ISSN:0741-0395    

DOI:10.1002/gepi.1370040403

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

年代:1987

数据来源: WILEY

摘要:

AbstractWhen linkage between a recessive Mendelian disease and specific candidate genes is investigated, identity by descent scores in affected sib pairs may be used for tests of linkage and heterogeneity. Statistical tests for performing this analysis are presented. The efficiency and statistical power of the method are also investigated using computer simulations.

ISSN:0741-0395    

DOI:10.1002/gepi.1370040404

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

年代:1987

数据来源: WILEY

摘要:

AbstractA large pedigree with high prevalence of heart disease is investigated to analyse the association between polymorphic blood markers and quantitative risk factors for cardiovascular disease. The analysis incorporates a familial correlation structure among the individuals in the pedigree and a generalized power transformation to induce approximate residual normality of the risk factors. A total of 380 marker/ risk factor combinations are analysed, and at the nominal 1 % significance level, positive associations are found between the A antigen of the ABO locus and both serum total cholesterol and low‐density lipoprotein cholesterol, and negative associations are found between the B antigen of the ABO locus and serum total cholesterol, and between the B allele of acid phosphatase (AP) locus and systolic blood pressur

ISSN:0741-0395    

DOI:10.1002/gepi.1370040405

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

年代:1987

数据来源: WILEY

摘要:

AbstractWhen nonrandom segregation of marker haplotypes from parents to offspring is detected, leading to an increased parental haplotype sharing by affected offspring, an association between the disease and the marker loci is often inferred. In this paper, we provide the uniformly most powerful test for testing nonrandom segregation, and compare the power of this test with another test that is available in the literature. Other statistical properties of the two tests are also discussed. Further, since nonrandom segregation can result from linkage of the disease and marker loci, when the hypothesis of random segregation is rejected, it is of interest to estimate the underlying parameter assuming linkage. We provide an estimation procedure.

ISSN:0741-0395    

DOI:10.1002/gepi.1370040406

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

年代:1987

数据来源: WILEY

摘要:

AbstractPrevalence rate of myotonic dystrophy (DM) was estimated in a large sample of the Italian population. Segregation analysis of the affected families suggests that subjects showing minor clinical signs, even in the absence of myotonic features, should be considered as bearers of the DM trait. An apparent excess of normal sibs among the offspring of DM subjects may be due to the late onset of the disease and possibly to a partial loss of affected individuals from the sample before diagnosis. Prevalence rate of DM in this study is estimated between 69 to 90 per million inhabitants; accordingly, DM might be the most frequent inherited neuromuscular disorder in human populations.

ISSN:0741-0395    

DOI:10.1002/gepi.1370040407

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe roles of major genes and multifactorial inheritance in the etiology of clubfoot (talipes equinovarus) were investigated based on 365 nuclear families consisting of three major racial groups of Hawaiians, Caucasians, and Orientals in Hawaii. Complex segregation analysis was employed using the mixed model with four parameters: major gene displacement (t), degree of dominance (d), gene frequency (q), and heritability (H). Heterogeneity was evident among the racial groups in the pattern of segregation of clubfoot. The most plausible genetic model is the presence of major gene effects with the multifactorial component for the Hawaiian and Caucasian groups, whereas no major gene action is evident for the Oriental group.

ISSN:0741-0395    

DOI:10.1002/gepi.1370040408

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

年代:1987

数据来源: WILEY

摘要:

AbstractWe performed hemoglobin electrophoresis in 30,400 apparently healthy black individuals in the Washington D.C. Metropolitan area, who were participating in a community based sickle‐cell screening program during the period 1978–1985. The overall prevalence of sickle‐cell trait was 6.7%. The frequency of sickle‐cell trait in various age groups, which included young children, adults, and individuals over 65 years of age, ranged from 6.4 to 7.4%. There were no statistically significant differences in the prevalence of sickle‐cell trait among the various age groups, nor did we detect a significant trend for increasing or decreasing sickle cell frequency with advancing age (P = 0.418). Thus, in this population sickle‐cell trait appears to have no effect on longevity. If the various complications of sickle‐cell trait reported in the literature are not fortuitous, their frequency and/or severity must be too low to affect preva

ISSN:0741-0395    

DOI:10.1002/gepi.1370040409

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

年代:1987

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370040401

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

年代:1987

数据来源: WILEY