摘要:

AbstractSulfate conjugation is an important pathway in the biotransformation of drugs and neurotransmitters. The thermolabile (TL) form of the enyzme phenol sulfotrans‐ferase (PST) catalyzes the sulfation of catecholamine neurotransmitters and drugs such as methyldopa and acetaminophen. Platelet TL PST activity was measured in blood samples from 232 individuals in 49 nuclear families. Correlations ranged from 0.43 to 0.45 for parent–offspring pairs and from 0.44 to 0.47 for siblings. Mother‐father correlations were not significantly different from zero. Although evidence was not unequivocal, both segregation and commingling analyses provided some support for a major gene influence on TL PST activity, with other variation due to polygenic background. In both sets of analyses, however, support for a major gene hypothesis depended upon skewness in the TL PST activity distribution. A polygenic model with high heritability (0.77) was most strongly supported with the log transformed data. These results confirm and extend a previous report of high heritability of TL PST based on a study of twins. In addition, our results raise the possibility of a major gene effect on this important catecholamine‐ and drug‐metabolizing enzyme–a possibility that can now be evaluated using biochemical

ISSN:0741-0395    

DOI:10.1002/gepi.1370050102

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

年代:1988

数据来源: WILEY

摘要:

AbstractHeterogeneity in determinants of familial resemblance of lipid and lipoprotein levels between populations in North America and Israel was investigated using path analysis. A common protocol, identical measurement techniques, and the same statistical procedures were used in the two samples. Both genetic (h2) and cultural (c2) determinants of inheritance were significant for all lipid variables in the two studies. Genetic and cultural heritability of total cholesterol (h2= 0.61, c2= 0.02), low‐density lipoprotein cholesterol (h2= 0.59, c2= 0.02), and high‐density lipoprotein cholesterol (h2= 0.55, c2= 0.06) did not differ significantly between North America and Israel, while there was a significant difference for triglyceride (h2= 0.41, c2= 0.07 in North America; h2= 0.61, c2= 0.05 in Israel). Secondary parameters of the path model describing intrafamilial environmental relationships differed between the two countries. In particular, there was a higher correlation between marital environments in Israel for all traits except triglyceride, and a larger effect of father's environment on offspring's environment in Israel for all traits. Within both populations, variation of plasma lipids and lipoproteins was mostly explained by genetic factors and random unmeasured environmental factors. The contribution of common family environment was found to be small, though statistically significant. This is probably due to homogeneity of the distribution of familian environmental determinants within both countr

ISSN:0741-0395    

DOI:10.1002/gepi.1370050103

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

年代:1988

数据来源: WILEY

摘要:

AbstractWe have examined the sample sizes required to detect linkage using the affected‐sib‐pair (ASP) method for major psychiatric disorders that are characterized by population prevalences of 1–7%, decreased penetrance, phenocopies, and heterogeneity. In addition, the nature of these illnesses makes large, multigenerational pedigrees difficult to collect. We calculated the sample sizes needed to have 80% power of finding linkage (with a type I error rate of 5%) under dominant and recessive models with incomplete penetrance and allowing for recombination rates of up to 10% between the disease gene and marker gene. We have assumed that the identical‐by‐descent (IBD) status of ASPs is known exactly. For a disease like schizophrenia (1% population prevalence), if 50% of families are linked to a marker locus at 10% recombination, then 60 and 120 pairs are needed under recessive and dominant inheritance, respectively. For a disorder such as major affective disorder (7% population prevalence), the sample size is similar if the inheritance is recessive, but larger (160 pairs) if the inheritance is dominant. We conclude that this method may be a reasonable alternative for psychiatric disorders, especially to confirm that a linkage found in a specific pedigree or population isolate is also present in the general p

ISSN:0741-0395    

DOI:10.1002/gepi.1370050104

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

年代:1988

数据来源: WILEY

摘要:

AbstractDietary intake has been hypothesized as being associated with several hormonally related cancers including prostate, breast, ovarian, and endometrial cancer. Because diet may affect hormones directly, it is logical to examine the effects of dietary factors on hormone production and levels. Therefore, a set of 72 male MZ and 83 male DZ twin pairs was ascertained from the Utah birth certificates. A quantitative food frequency questionnaire was administered and blood samples were drawn for hormonal assays. Heritability estimates for hormonal levels were calculated indicating a range from no heritability for sex hormone binding globulin (SHBG), estrone, and testosterone glucuronide to 70% for androstanediol glucuronide and luteinizing hormone. To examine nutritional factors, the difference in hormone and SHBG levels between each MZ twin and his co‐twin were correlated with the difference in nutrient intake. Weight and obesity were significantly correlated with plasma testosterone and follicle stimulating hormone. Fat intake showed a significant association with testosterone. Androstanediol glucuronide, a steroid that reflects tissue formation of dihydrotestosterone, was inversely correlated with caloric intake, theobromine and caffeine. Testosterone glucuronide exhibited significant correlations with calories and vitamin A. This study suggests that dietary intake affects plasma sex‐steroid levels in

ISSN:0741-0395    

DOI:10.1002/gepi.1370050105

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

年代:1988

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370050106

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

年代:1988

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370050107

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

年代:1988

数据来源: WILEY

ISSN:0741-0395    

DOI:10.1002/gepi.1370050101

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

年代:1988

数据来源: WILEY