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1.
目的 研究优势眼与利手在青少年屈光参差者中的相关性。方法327例青少年屈光不正者,在医学验光基础上,利用简化的卡洞法检测双眼中的优势眼,利用问诊方式判断利手。结果右眼为优势眼占64.5%;左眼为优势眼占35.5%。近视度数右眼高者与右眼优势眼对应者占30.9%,左眼高者与左眼优势眼对应者占11.3%。右利手占97.6%,左利手占2.4%。右眼度数高同是右利手占46.5%,左眼度数高同是左利手占1.5%。右眼优势眼同时为右利手占64.5%,左眼优势眼同时左利手占2.4%。结论青少年近视性屈光不正者,优势眼和利手同一侧的一致性较高,相关性具有统计学意义。  相似文献   

2.
目的 研究优势眼与利手在青少年屈光参差者中的相关性.方法 327例青少年屈光不正者,在医学验光基础上,利用简化的卡洞法检测双眼中的优势眼,利用问诊方式判断利手.结果 右眼为优势眼占64.5%;左眼为优势眼占35.5%.近视度数右眼高者与右眼优势眼对应者占30.9%,左眼高者与左眼优势眼对应者占11.3%.右利手占97.6%,左利手占2.4%.右眼度数高同是右利手占46.5%,左眼度数高同是左利手占1.5%.右眼优势眼同时为右利手占64.5%,左眼优势眼同时左利手占2.4%.结论 青少年近视性屈光不正者,优势眼和利手同一侧的一致性较高,相关性具有统计学意义.  相似文献   

3.
目的 利用双生子人群估计学龄儿童行为指标的遗传度,为降低儿童行为问题的发生提供依据.方法 采用Achenbach's儿童行为量表对在呼和浩特市募集的166对6~12岁双生子心理行为问题进行调查.对调查结果进行结构方程模型拟合,估算学龄儿童行为指标的遗传度.结果 行为总粗分遗传度为男30.26%,女32.80%;各行为分因子遗传度分别为焦虑/抑郁(男46.79%,女74.99%)、退缩(男56.45%,女78.33%)、思维(男58.95%,女63.25%)、注意力(男79.14%,女40.11%)、社会化问题(男26.13%,女52.09%)、违规行为(男37.09%,女0.00%)、攻击性行为(男84.57%,女50.15%)、其他问题(男75.21%,女70.29%).注意力和攻击性行为的遗传度存在性别效应,男生的遗传度均明显高于女生.年龄对学龄儿童行为问题的遗传效应无明显影响.结论 学龄儿童行为问题受遗传与环境因素的共同影响,注意力和攻击性行为的遗传效应可能存在性别作用.  相似文献   

4.
目的 探讨支持向量机在环境和遗传因素对2型糖尿病预测中的应用前景.方法 建模数据库来源于2001 - 2004年中国双生子登记系统,以是否发生2型糖尿病为预测标签,以13个环境因素和5个遗传因素为预测因子,应用Matlab软件建立基于支持向量机的预测模型.结果 环境因素对2型糖尿病的预测模型中,应用线性核函数拟合模型,回代训练样本准确率和预测检验样本准确率分别为82.50%和87.50%,当考虑遗传因素共同作用后,回代训练样本准确率和预测检验样本准确率分别提高1.67%和2.88%;两个预测模型中,应用径向基核函数拟合模型,回代训练样本准确率为100.00%,但预测检验样本准确率仅为86.54%,模型均出现过度拟合现象;应用sigmoid核函数拟合模型,回代训练样本准确率为81.67%,预测检验样本准确率为86.54%,预测效果略差.在环境和遗传因素对2型糖尿病的预测模型中,应用线性核函数拟合模型时,灵敏度为93.33%,特异度为71.42%,优于基于径向基核函数和sigmoid核函数的预测模型.结论 基于线性核函数建立的模型对2型糖尿病发生的预测效果较好,并且综合环境和遗传因素共同作用对2型糖尿病的预测准确率要高于仅考虑环境因素的预测效果,应用支持向量机在解决小样本、非线性、高维模型识别问题中具有良好的应用前景.  相似文献   

5.
浙江省815例白癜风患者遗传流行病学研究   总被引:1,自引:0,他引:1  
目的探讨白癜风可能的遗传模式。方法通过调查表得到浙江地区815例白癜风患者及其一、二级亲属的数据。815例白癜风患者中男411例(50.43%),女404例(49.57%),年龄2月龄至71岁。由于缺乏当地白癜风患病率普查数据,因此设立对照组以方便遗传模式及遗传度的计算。468名对照组性别及各年龄段比例与病例组具有可比性。应用Penrose法、Falconer回归法及SAGE—REGTL软件对白癜风患者进行遗传方式分析,遗传度计算及复合分离分析。结果所调查的815例白癜风先证者中,有家族史者128例,无家族史者687例,遗传率15.70%。Penrose法计算出同胞患病率(s)/人群患病率(q)为41.76,不接近1/2q(260.42),也不接近1/4q(130.21),而接近1/√q(22182),提示白癜风符合一种多基因遗传模式。白癜风患者一、二级亲属遗传度分别为59.61%和55.20%,加权遗传度为58.7%。复合分离分析显示孟德尔显性、隐性、加性主基因模型假设均被接受;单纯环境与非传递模型被拒绝;以AIC值判断,显性模型拟合程度最好。结论遗传因素在白癜风发病中占有重要作用,白癜风符合一种多基因或多因子遗传模式,存在主基因效应。  相似文献   

6.
刘韵源  刘嘉 《中国公共卫生》2000,16(11):968-970
借助模糊状态概念、交叉积差和统计量和信息量寻优标准,转好实现最佳非饱和模型拟合与归因危险度估计,突破了传统谱系套模型限定的约束,能找出显著交互效应项,有助于揭示微弱相关影响因素的多因素联合作用。  相似文献   

7.
借助模糊状态概念、交叉积差和统计量和信息量寻优 标准,转好实现最佳非饱和模型拟合与归因危险度估计,突破 了传统谱系套模型限定的约束,能找出显著交互效应项,有助 于揭示微弱相关影响因素的多因素联合作用。  相似文献   

8.
成年双生子血尿酸遗传度研究   总被引:1,自引:0,他引:1       下载免费PDF全文
目的 用双生子研究方法 对成年人血尿酸的遗传度进行估计.方法 从青岛双生子库募集成年双生子.测量身高、体重和血尿酸.相同性别的双生子采用16个多态标记进行卵型鉴定.通过校正年龄、性别和BMI,来构建结构方程模型估计遗传度.结果 共收集687对双生子数据,其中同卵双生子420对,异卵双生子267对.经平方根转换后,男性血尿酸水平(17.47±1.91)略高于女性(15.22±1.70)(P<0.0001),通过校正年龄、性别和BMI后双生子血尿酸的组内相关系数分别为,同卵双生子0.70、异卵双生子0.40.运用性别限制模型进行拟合,最佳模型AE模型,加性别遗传因素和特殊环境因素共同作用血尿酸的水平.血尿酸的遗传度为70.5%(95%CI:65.9~74.6),特殊环境因素占29.5%(95%CI:25.4~34.2).结论 遗传因素是影响样本双生子血尿酸水平的主要因素.  相似文献   

9.
目的了解成人双生子血清总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)的水平及其遗传度。方法选择青岛市双生子库中316对18到60岁的健康成人双生子,用自动生化分析仪检测其空腹血清TC、HDL-C、LDL-C、TG的浓度。鉴定卵性后,用Mx软件拟合遗传模型,调整性别、年龄后,计算血脂相关指标的遗传度。结果双生子空腹血清TC、HDL-C、LDL-C、TG水平的均值分别为(4.52±1.08)、(1.46±0.39)、(2.58±0.79)、(1.11±0.77)mmol/L。Mx软件拟合结构方程模型结果显示,TC、HDL-C和LDL-C三项指标的最适模型为AE模型,其遗传度依次为53%、62%和57%。TG的最适模型为CE模型,遗传度为0。结论遗传因素和环境因素对TC、HDL-C和LDL-C的浓度都有重要影响,而TG主要受到环境因素的影响。  相似文献   

10.
目的 探究体力活动对2型糖尿病遗传效应的修饰作用。方法 利用中国双生子登记系统在11省/市募集的12 107对≥ 30岁同性别双生子,拟合单变量交互作用模型计算体力活动对2型糖尿病遗传效应的修饰作用。结果 调整年龄、性别后,2型糖尿病的遗传度为0.56(0.31~0.84)。体力活动达标可降低2型糖尿病的遗传效应。体力活动达标双生子2型糖尿病的遗传度为0.46(0.06~0.88),低于相同模型中体力活动未达标双生子2型糖尿病的遗传度[0.68(0.36~0.94)]。结论 2型糖尿病属于中度遗传疾病,体力活动可修饰2型糖尿病的遗传效应。  相似文献   

11.
目的分析36对双胎儿童的孤独症谱系障碍(ASD)的同患率、广义遗传度,建立双胎回归模型,探讨随访资料中临床评估结果的影响因素。方法收集2016-2018年就诊于复旦大学附属儿科医院的部分双胎儿童,纳入标准:双胎至少一胎为ASD患儿,或双胎均为正常发育(NT)儿童,收集儿童的一般情况,采用孤独症诊断观察量表(ADOS)和Griffiths精神发育量表(GMDS)对儿童的社交能力和总发育商进行评估,使用R统计建模语言和双胎分析软件包mets建立模型。结果在36对双胎中,同卵双胎ASD共患率为66.7%,异卵双胎ASD共患率则为16.7%;ASD风险因素的最佳拟合为包含性别和体重的AE模型,广义遗传度接近90.4%(95%CI:65.2%~115.7%),但临床协变量和遗传因素对ASD预测的作用均不显著;孤独症诊断观察量表中重复和刻板行为(ADOS-RRB)的最优模型为加入自闭症诊断、体重、受孕方式与患儿年龄在内的AE遗传模型,孤独症诊断观察量表中社交情感(ADOS-SA)的最优拟合模型为引入性别、患儿年龄、母亲教育程度与受孕方式在内的CE遗传模型,Griffiths精神发育量表中总发育商(GMDS-DQ)的最优模型为ASD诊断、是否早产、性别在内的CE遗传模型,非共享环境因素对ADOS-RRB(P=0.000 2)、ADOS-SA(P<0.000 1)以及GMDS-DQ(P<0.000 1)的影响差异均有统计学意义。结论遗传因素是ASD发生的重要因素,非共享环境因素与ASD临床评估结果具有一定相关性。  相似文献   

12.
OBJECTIVES: The relative contributions of genetic and environmental variables to within-household clustering of quantitative traits in household surveys are poorly characterized. We estimated shared genetic and shared environmental contributions to within-household correlation for anthropometric variables and cardiovascular disease risk factors. STUDY DESIGN AND SETTING: Data were analyzed for the Health Survey for England 1998, a representative national household survey. Two-generation pedigrees were defined using information for relationships within households. After standardizing for age and sex, data were analyzed for 11 quantitative traits. Variance components models were fitted to estimate the proportion of variance due to additive genetic variance or shared environmental effects. RESULTS: Within-household correlation coefficients for all related and unrelated subjects ranged from 0.10 for C-reactive protein to 0.31 for height. Pairwise correlations between related individuals within households were consistently higher than those between unrelated individuals. Estimated heritability ranged from 6% for diastolic blood pressure to 40% for serum cholesterol. The proportion of variance attributable to shared environmental effects ranged from 8% for cholesterol to 24% for height. CONCLUSION: In this large, representative national sample of generally small families, estimates for heritability were generally lower than previously reported, whereas the contribution of shared environment and individual-level variation were greater.  相似文献   

13.
OBJECTIVE: It is commonly recognized that genetic, environmental, behavioral, and social factors are involved in the development of obesity. The family environment may play a key role in shaping children's eating behaviors. The purpose of this study was to estimate the degree of familial resemblance in eating behavioral traits (cognitive dietary restraint, disinhibition, and susceptibility to hunger). RESEARCH METHODS AND PROCEDURES: Eating behavioral traits were assessed with the Three-Factor Eating Questionnaire in 282 men and 402 women (202 families) from the Quebec Family Study. Familial resemblance for each trait (adjusted for age, sex, and BMI) was investigated using a familial correlation model. RESULTS: The pattern of familial correlation showed significant spouse correlation for the three eating behavior phenotypes, as well as significant parent-offspring and sibling correlations for disinhibition and susceptibility to hunger. According to the most parsimonious model, generalized heritability estimates (including genetic and shared familial environmental effects) reached 6%, 18%, and 28% for cognitive dietary restraint, disinhibition, and susceptibility to hunger, respectively. DISCUSSION: These results suggest that there is a significant familial component to eating behavioral traits but that the additive genetic component appears to be small, with generalized heritability estimates ranging from 6% to 28%. Thus, non-familial environmental factors and gene-gene and gene-environmental interactions seem to be the major determinants of the eating/behavioral traits.  相似文献   

14.
恒牙列拥挤的双生子研究   总被引:1,自引:0,他引:1  
目的 通过双生子研究遗传和环境因素对恒牙列拥挤形成所起的作用,以进一步研究恒牙列拥挤的影响因素。方法 以48对双生子作为研究对象,应用卵型鉴定技术分为单卵双生子组(MZ)和二卵双生子组(DZ),采取牙[牙合]石膏模型并进行测量,获取牙齿近远中径大小、牙弓弧长及牙列拥挤度等数据;采用Holzinger经典双生子法计算遗传度。结果 同卵与二卵双生于牙齿近远中径的平均值差别无统计学意义。说明牙齿近远中径在同卵.二卵双生子样本中平均水平接近。上下颌牙量遗传度较高。上颌为69.97%,下颌为75.73%;上颌牙弓弧长的遗传度(71.26%)明显高于下颌(31.33%);单卵双生子和二卵双生子上下颌牙齿的拥挤度的对内相关系数较为接近,二卵双生子略低。遗传度很低,上颌为4.73%,下颌为10.3%。结论 上下颌牙量大小和上颌牙弓弧长受较强遗传控制。下颌牙弓弧长受弱遗传控制,恒牙列拥挤度遗传度很低,受环境因素影响较大。  相似文献   

15.
【目的】 利用双生子人群估计学龄儿童气质维度的遗传度,探讨遗传和环境因素对我国学龄儿童气质发展的影响。 【方法】 采用Carey儿童气质问卷对127对6~12岁双生子气质进行测评。对测评结果进行结构方程模型拟合,估算学龄儿童气质维度的遗传度。 【结果】 儿童气质类型遗传度为50.57%;各维度遗传度分别为活动水平(男39.30%,女88.39%)、节律性(男46.26%,女60.65%)、趋避性(男82.22%,女82.23%)、适应性(男44.31%,女44.31%)、反应强度(男41.84%,女52.05%)、坚持性(男90.40%,女90.40%)、注意分散度(男72.46%,女72.46%)、反应阈(男30.03%,女44.99%)。活动水平的遗传度存在性别效应,女童的遗传度均明显高于男童。年龄对学龄儿童气质的遗传效应无明显影响。 【结论】 学龄儿童气质受遗传与环境因素的共同影响,活动水平的遗传效应可能存在性别作用,女童的活动水平可能更多受遗传因素的影响。  相似文献   

16.
Linear, logistic, and multivariate mixed model analyses were applied to simulated data of five quantitative traits and a binary liability trait to detect associations with sequence variants in seven genes. Infrequent site variants (<1%) were eliminated and conservative step‐wise procedures were used to reduce the number of variants fitted. Random effects accounting for additive genetic relationships between individuals and for common environment effects were fitted to reduce spurious significant results. Five sites in genes 1, 2, and 6 had significant effects (p < 0.0001) on the traits and were found in both replicates studied. Survival analysis using a Weibull model identified two significant sites for disease age at onset. Other less significant sites may be false positives or due to founder effects. This approach was effective in identifying putative sites while accounting for polygenic and environmental sources of variation. © 2001 Wiley‐Liss, Inc.  相似文献   

17.
The genetic influence on susceptibility to diseases of the respiratory system and all-cause mortality was studied using data for identical (MZ) and fraternal (DZ) twins. Data from the Danish Twin Register include 1344 MZ and 2411 DZ male twin pairs and 1470 MZ and 2730 DZ female twin pairs born between 1870 and 1930, where both individuals were alive on 1 011943. We used the correlated gamma-frailty model. Proportions of variance in frailty attributable to genetic and environmental factors were assessed using the structural equation model approach. For all-cause mortality the correlation coefficients of frailty for MZ twins tend to be higher than for DZ twins. For mortality with respect to respiratory diseases this effect was only seen in females, whereas males showed the opposite effect. Five standard biometric models are fitted to the data to evaluate the magnitude and nature of genetic and environmental factors on mortality. Using the best fitting biometric model heritability for cause of death was found to be 0.58 (0.07) for all-cause mortality (AE-model) and zero for diseases of the respiratory system for males. Heritability was 0.63 (0.11) for all-cause mortality (DE-model) and 0.18 (0.09) for diseases of the respiratory system (DE-model) for females. The analysis confirms the presence of a strong genetic influence on individual frailty associated with all-cause mortality. For respiratory diseases, no genetic influence was found in males and only weak genetic influence in females. The nature of genetic influences on frailty with respect to all-cause mortality is probably additive in males and dominant in females, whereas for frailty with respect to deaths caused by respiratory diseases in females, there are genetic factors present which are caused by dominance. Environmental influences are non-shared with exception of frailty with respect to respiratory diseases in males, where the shared environment plays an important role.  相似文献   

18.
Path analysis of nuclear family data has been widely applied to resolve genetic and environmental sources of familial resemblance. Here we report the results of a systematic evaluation of the effects of departures from five modeling assumptions often made when analyzing nuclear family data; i) the observed environmental index is unaffected by the genotype, ii) the basis of marital resemblance is correctly specified in the model, iii) there are no intergenerational differences in either the genetic or cultural heritability, iv) there is no genetic dominance, and v) there is no genotype by family environment interaction. "Deterministic simulations" identified various situations where model misspecification could lead to substantial bias in the estimation of the heritabilities. For these situations, "stochastic simulations" were performed to determine whether the "goodness-of-fit" test used in path analysis would correctly reject the misspecified model. In samples of 500 nuclear families, each comprising two parents and two children, the goodness-of-fit test was found to be sensitive to misspecifications of the source of marital resemblance and the existence of intergenerational differences in heritabilities, although reduced power would make the test less sensitive in smaller samples. The test was largely insensitive to misspecifications of possible genetic effects on the environmental index, and to the existence of multiplicative interaction between the genotype and familial environment. When genetic effects on the index are ignored, the genetic heritability (h2) is underestimated, the cultural heritability (c2) is overestimated, but h2+c2 remains unchanged. Neglecting the interaction was found to result in an overestimate of h2.  相似文献   

19.
We applied twin methodology to female and male twin pairs to further understand the nature of the relation between two behaviors associated with eating disorders—binge eating (BE) and night eating (NE) in an effort to determine the extent of overlap of genetic and environmental factors influencing liability to these behaviors. We calculated heritability estimates for males and females for each behavior and applied bivariate twin modeling to the female data to estimate the genetic and environmental correlation between these two traits. Data on BE and NE were derived from the Swedish Twin study of Adults: Genes and Environment (STAGE) of the Swedish Twin Registry (STR; N = 11,604). Prevalence estimates revealed sex differences with females more likely to endorse BE and males more likely to endorse NE. In males, we were only able to estimate univariate heritabilities due to small sample sizes: The heritability for BE was 0.74 [95% CI = (0.36, 0.93)] and for NE was 0.44 [95% CI = (0.24, 0.61)]. The best fitting bivariate model for females included additive genetic and unique environmental factors as well as the genetic correlation between BE and NE. Heritability estimates were 0.70 [95% CI = (0.26, 0.77)] for BE and 0.35 [95% CI = (0.17, 0.52)] for NE. The genetic correlation, 0.66 [95% CI = (0.48, 0.96)] suggests considerable overlap in the genetic factors influencing liability to BE and NE. In females, there is considerable overlap in the genetic factors that contribute to these traits, but the incomplete overlap allows for the influence of independent genetic and environmental factors as well. BE and NE in females are therefore best conceptualized as related but not identical traits.  相似文献   

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