学龄双生子儿童头面部特征的遗传学分析

为探讨遗传与环境因素对学龄双生子儿童头面部特征的影响, 对呼和浩特市和包头市7-12岁369对双生子儿童(同卵180对, 同性别异卵141对, 异性别异卵48对)的16项头面部指标进行活体测量。采用通径分析方法, 用Mx软件拟合最佳结构方程模型, 计算各指标遗传与环境方差组分, 分析年龄、性别的作用。结果发现, 校正年龄后, 头部指标中头围的遗传度(男66%, 女66%)较高; 面部指标中, 容貌面高的遗传度(男73%, 女84%)最高, 其次为鼻宽(男57%, 女67%)、眼内角间宽(男57%, 女50%)和额最小宽(男50%, 女50%); 头长(男64%, 女25%)、头宽(男26%, 女82%)、眼外角间宽(男76%, 女34%)和容貌耳长(男23%, 女70%)的遗传度存在一定的性别差异。表明遗传因素与环境因素对学龄双生子儿童的头面部发育均有一定影响, 其中遗传因素对男女头围及容貌面高、男性头长和眼外角间宽、女性头宽、鼻宽、口宽、容貌耳长的影响相对较大。     

遗传和环境因素对儿童青少年身体高度及其比例的影响

目前有关儿童青少年坐高、下肢长及其比值的报道多为非双生子人群的研究。为了解遗传和环境因素对儿童青少年坐高、下肢长及坐高与下肢长比值影响的相对大小,我们对796对6～18岁双生子的身高和坐高进行了测量,计算下肢长及坐高与下肢长比值,采用结构方程模型分析其遗传和环境相对效应。结果发现,校正年龄后,男女15～18岁年龄组坐高和下肢长的遗传度(0.63～0.78)均分别高于同性别低年龄段儿童青少年(0.31～0.68);坐高与下肢长比值的遗传度除9～11岁女生(0.84)外,其他年龄组均较低(男0.16～0.46,女0.21～0.57);共同环境因素和特殊环境因素对6～14岁儿童青少年各指标的作用较大。本研究提示,在快速发育时期,坐高、下肢长和坐高与下肢长比值对环境因素更为敏感,遗传度较低;机体越成熟,其遗传效应更强。     

芜湖地区青少年儿童皮下脂肪及身体围度发育规律初探

分析了安徽省芜湖地区1217名城乡在校中小学生四项皮褶厚度及四项身体围度随年龄变化的规律,尤其是青春期的变化;以及营养、气候等环境因素对儿童青少年身体发育的影响。结果表明：在即将进入青春发育期时,男性四肢部皮下脂肪迅速减少;女性皮下脂肪在青春期迅速增厚;身体围度则随年龄增长而增加,在青春后期,围度保持在一定水平。     

青少年双生子体型指征相关指标的遗传度研究(英文)

目的:用经典的双生子设计探讨遗传因素对青少年身高、体重、体质指数(BMI)等体型指征的影响程度。方法:从青岛市双生子库中选择自愿参加本研究的362对11-19岁双生子,测量身高、体重。同性别的双生子通过16个多态标记进行卵型鉴定,在此基础上,应用Mx软件构建结构方程模型分析计算遗传度。结果:对362对有效双生子数据进行分析,其中同卵双生子194对,异卵双生子168对,身高的最佳拟合模型ACE模型,体重和BMI的最佳拟合模型为AE模型。调整年龄性别后,身高的遗传度为66%,体重的遗传度为84%,体质指数的遗传度为75%。结论:在青少年体型指征的相关指标中,身高、体重、BMI受遗传因素影响都较大。     

新疆伊犁哈萨克族成人身体围度特征的分析

目的:研究新疆伊犁哈萨克族成人身体围度的特征。方法:本次研究中针对新疆伊犁哈萨克族374例(男性192例,女性182例)成人的身体围度进行了测量以及做了相关的分析。对年龄组间围度值的变化进行方差分析,对年龄与围度之间的关系进行相关分析。并与我国其他26个族群的围度值进行聚类分析。结果:该区男性腰围、腹围年龄组间的差异具有统计学意义;该区女性除头围外的12项围度值在不同年龄组间差异均有统计学意义。女性围度值各年龄组间的差异比男性更加明显。直线相关分析,男性呼气围、腰围、腹围和臀围均与年龄呈正相关,女性颈围、躯干各部分围度和上肢围度均与年龄呈正相关。新疆伊犁哈萨克族在26个族群中头围、胸围、腹围、臀围、大腿围和小腿围6项围度值均处于较高水平。聚类分析显示,哈萨克族围度值与乌孜别克族最接近,我国20个人群围度比较,表明哈萨克族族围度值较大。结论:伊犁哈萨克族身体围度值较大,具有东亚类型族群的围度特征。     

中国汉族人的身体围度

2009～2013年在中国22个省、自治区测量了26695例(乡村男性8174例,城市男性4791例,乡村女性8327例,城市女性5403例)的头围、颈围、平静胸围、吸气时胸围、呼气时胸围、腹围、臀围、大腿围、小腿围、上臂围、前臂围、上臂最大围值,进行了围度与纬度、经度、年龄的相关分析,城市与乡村汉族、北方与南方汉族身体围度均数的比较。结果发现,男性的上臂围、上臂最大围与纬度无显著相关,其余10项围度均与纬度呈显著正相关。女性12项围度均与纬度呈显著正相关。男性、女性12项围度均与经度呈显著正相关,男性四肢围度多与年龄呈显著负相关。女性下肢围度也与年龄呈显著负相关,但上肢3项围度与年龄呈显著正相关。男性、女性躯干5项围度、颈围随年龄增加而增大。北方男性除头围、上臂围值与南方男性接近外,其余10项围度值均大于南方男性。北方女性12项围度值均大于南方女性。城市、乡村汉族12项围度的差异均具有统计学意义。城市汉族的各项围度均大于乡村汉族。     

双生子多巴胺D3受体基因多态性对儿童体成分的影响

均衡的体成分构成对维持机体的健康状态具有重要作用,体成分受遗传与环境因素的共同影响。多巴胺参与摄食、运动及认知等活动的调节,多巴胺D3受体（DRD3）对多巴胺神经通路起关键调节作用,进而对摄食功能发挥作用,从而可能对体成分产生影响。为了解遗传与环境因素对双生子儿童体成分的影响,并探讨DRD3基因单核苷酸多态性（SNP）与体成分的相关性,对160对4-12岁双生子肱三头肌皮褶厚度（d₁）、肩胛下皮褶厚度（d₂）、髂前上棘位皮褶厚度（d₃）和体质量（m）进行了测量,计算d₄(d₁+d₂)、d₅(d₂/d₁),体脂率（P_f）、瘦体质量（m_l）;从口腔拭子中提取全基因组DNA;通过Amp FISTR Sino filerPlus试剂盒分析确定卵型;采用SNaPshot技术对DRD3基因4个SNP位点进行检测;使用Mx软件估算各指标遗传度;运用广义估计方程模型分析各指标与DRD3基因SNP的相关性。校正年龄效应后,除个别指标（d₃, m_l）外,男女生指标遗传度（h）学龄前期总体偏低,且某些指标（d₂, d₄, P_f, m_l）的遗传度存在一定的性别差异。d₂分别与rs324029、rs226082存在相关（P<0.05）; d₃分别与rs2134655、rs226082存在相关（P<0.05）;d₅分别与rs2134655、rs167771存在相关（P<0.05）;P_f分别与rs226082、rs167771存在相关（P<0.05）;m_l分别与rs2134655、rs226082、rs167771存在相关（P<0.05）。本研究结果表明,遗传和环境因素对儿童体成分发育均有影响,但遗传效应可能存在一定的发育阶段和性别差异;DRD3基因SNPs与儿童的体成分可能存在一定的相关性。     

维吾尔族大学生身体成分与身体形态指标的关系

目的 了解维吾尔族大学生体成分及身体形态指标的关系,为维吾尔族大学生肥胖干预以及学生营养教育、科学参与体育锻炼提供理论依据.方法 随机抽取新疆师范大学14个班的在校维吾尔族大学生659名,采用人体成分分析仪及《国家学生体质健康标准》规定的项目和测试要求进行测试,比较不同体成分大学生间身体形态指标.结果 维吾尔族男女大学生肥胖组BMI指数均高于正常组,超重组的腰臀比均高于正常组,差异均有统计学意义(P值均＜0.01);正常、超重、肥胖3组的上臂皮褶厚度差异无统计学意义(P＞0.05).结论 维吾尔族大学生的脂肪主要堆积于腹部.应在控制高热量饮食的基础上进行科学的体育锻炼,加强营养知识的宣传和普及,倡导平衡膳食合理营养.     

基于景观遗传学的滇金丝猴栖息地连接度分析

结合景观遗传学,应用最小费用距离模型对物种栖息地进行连接度分析,能够为生物多样性保护和自然保护区管理提供更加真实准确及可实践操作的指导。选取滇金丝猴这一珍稀濒危物种,结合景观遗传学,应用最小费用距离模型对其栖息地进行了连接度和潜在扩散廊道分析。并且通过连接度的分析和制图绘制出了更为准确的种群间潜在扩散廊道,确定了受人工障碍影响的廊道及敏感区域。结果表明,研究区内的5个亚群中,仅S3亚群内的5个猴群保持着较好的连接度,总体来说,各亚群内的连接度相对于各亚群间连接度保持的较好。除S3亚群中猴群间的潜在扩散廊道较为理想外,其余种群间的潜在扩散廊道均受人工斑块的影响,多数廊道被人工障碍阻断,或面临即将被阻断的情况,对于滇金丝猴的扩散交流影响较大。敏感区域多集中在中南部的3个亚群间,这些敏感区域应作为景观恢复及保护区规划的重要优先区域。     

小儿重症肺炎红细胞体积分布宽度与患儿近期预后的相关性分析

目的:探讨小儿重症肺炎红细胞体积分布宽度(RDW)与患儿近期预后的相关性。方法:选择107例重症肺炎患儿为研究对象,检测患儿入院时RDW水平,记录相关实验室检查指标及住院后28d的转归情况,将患者分为死亡组和存活组,高RDW组和正常RDW组,分析各组之间相关指标的差异,并探讨RDW与患儿近期预后的关系。结果:死亡组患儿的入院急性病生理学和长期健康评价评分Ⅱ(APACHEⅡ)评分、降钙素原(PCT)、超敏C-反应蛋白(hs-CRP)、白细胞计数(WBC)、中性粒细胞百分比(PMN)、血沉(ESR)高于存活组(P0.05),RDW水平亦高于存活组(P0.05);高RDW组患儿APACHEⅡ评分、PCT、hs-CRP、WBC、PMN、ESR高于正常RDW组,死亡率亦高于正常RDW组(P0.05)。Logistic回归分析显示RDW水平是重症肺炎患儿近期死亡的独立危险因素(OR=2.025,95%CI:1.252~4.243,P0.05);ROC曲线分析显示:RDW水平预测重症肺炎患儿死亡的ROCAUC为0.801,灵敏度为82.0,特异度为74.4,最佳诊断截点为16.35%。结论:RDW水平可能是重症肺炎患儿近期预后不良的独立危险因素,并对患儿预后可能具有较好的预测价值。     

Relationship of lead and essential elements in whole blood from school-age children in Nanning,China

ObjectivesThe aim of this study was to investigate blood lead level and its relationship to essential elements (zinc, copper, iron, calcium and magnesium) in school-age children from Nanning, China.MethodsA total of 2457 children aged from 6 to 14 years were enrolled in Nanning, China. The levels of lead (Pb), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca) and magnesium (Mg) were determined by an atomic absorption spectrometer.ResultsThe mean blood lead level (BLL) was 57.21 ± 35.00 μg/L. 188 (7.65%) asymptomatic children had toxic lead level higher than 100 μg/L. The school-age boys had similar lead level among different age groups, while the elder girls had less BLL. The blood Zn and Fe were found to be increased in the boys with elevated BLL, but similar trends were not observed in the girls. Positive correlations between Pb and Fe or Mg (r = 0.112, 0.062, respectively, p < 0.01) and a negative correlation between Pb and Ca (r = −0.047, p < 0.05) were further established in the studied children.ConclusionsLead exposure in school-age children was still prevalent in Nanning. The boys and girls differed in blood levels of lead and other metallic elements. Lead exposure may induce metabolic disorder of other metallic elements in body.     

Genetic and environmental influences on bilateral dental asymmetry in Northwest Indian twins

The role of genetic and environmental factors on dental asymmetry (in maximum crown dimensions) was examined using 58 pairs of twins (23 MZ and 35 DZ) from Chandigarh, India. The t'-test for equality of means by zygosity showed only one variable significantly different among 56: this is ascribable to Type 1 error. Heterogeneity of MZ-DZ total variance was observed in 42.9% of traits of the two types (fluctuating and directional) of bilateral asymmetry. In general, MZ twins showed higher total variance than DZ pairs. MZ twins also showed stronger environmental covariance for a majority of the traits. Dental asymmetry measures thus yielded consistently low genetic variance ratios and indicated predominantly complex environmental determinism. Since fluctuating asymmetry is widely believed to be an environmental stress indicator, this data set allows confirmation of methods for detecting unequal environmental influences on the zygosities which bias estimates of genetic variance and heritability.     

Plantar pressures in identical and non-identical twins

Identifying environmental risk factors for musculoskeletal disorders is challenging due to the number of potential confounders. Twins are of particular interest for researchers interested in studying these types of problems due to their inherent control for the influence of genetic factors. In twin studies, this population can allow environmental risk factors to be more easily identified, and this type of study design may allow the role of biomechanics in injury and disease to be further explored. At present, it is unclear if foot function displays more similarity between certain types of twins. In this study, we hypothesized that the plantar pressures of monozygotic (identical) twins would be more similar between pairs than dizygotic (non-identical) twins. We measured static and dynamic plantar pressures from five pairs of each twin type. Statistical parametric modeling was used to compare pressure distributions at the sensor level. For >80% of stance phase, the pixel level analysis indicated that monozygotic twins had less variation in plantar pressure between pairs. The average z-statistic across the entire trial was 0.88 for the monozygotic group and 1.13 for the dizygotic group. In this study we provide evidence of greater similarity of plantar pressures in monozygotic twin pairs compared to dizygotic twins. This finding supports the use of co-twin studies investigating potentially modifiable environmental and biomechanical risk factors for musculoskeletal conditions that affect the foot and ankle.     

Familial resemblance for anthropometric traits in dizygotic twins and siblings

Familial resemblance for fifty anthropometric traits was studied on a sample of 45 MZ, 101 DZ twin pairs and their 125 singleton siblings. Intraclass correlation coefficients were significant for all the traits. However, resemblance within DZ twin pairs was significantly greater than within sibs for 22 variables, showing that the former had a more correlated environment than the latter. The study also showed that head and facial traits were relatively more stable to the environmental factors than the body traits and hence more suitable for cross-cultural comparisons. The study listed measures of girth and skinfold, thickness as the most labile traits.     

Skeletal maturity and bone growth in twins

Heritability of skeletal maturity and bone growth is discussed on the basis of intrapair resemblances (correlation coefficients) and differences (revised percent deviations) in mono- and dizygotic twins and random pairs of unrelated children. A series of 1072 radiographs of the right hand and wrist in 63 male and 70 female pairs of monozygotic twins, and 25 male and 21 female pairs of dizygotic twins aged 12 to 18 years studied longitudinally in Tokyo were used. Skeletal maturity based on the TW2 age suggests higher heritability than bone growth based on the second metacarpal dimensions. In the latter, length has higher heritability than width and cortical thickness. A dosage effect seems to be suggested in width and some indices in the second metacarpal, but is not confirmed in skeletal maturation.     

Genetic susceptibility to prostate, breast, and colorectal cancer among Nordic twins

To investigate the role of genetics in the development of cancer, we developed a new approach to analyze data on prostate, breast, and colorectal cancer from the Swedish, Danish, and Finnish twin registries on monozygotic (MZ) and same-sex dizygotic (DZ) twins. In the spirit of a sensitivity analysis, we modeled genetic inheritance as either an autosomal recessive or dominant cancer susceptibility (CS) genotype that involves either a single gene, many genes with equal allele frequencies, or three genes with a ninefold range of allele frequencies. We also modeled the joint probability of cancer incidence among five age categories, conditional on the presence or absence of the CS genotype. The main assumptions are: (1) The joint distribution of unobserved environmental effects in a twin pair conditional on the presence or absence of the CS genotype is the same for MZ and DZ twins, (2) the probability of cancer conditional on the presence or absence of the CS genotype and the unobserved environmental effects (i.e., the gene-environment interaction) is the same for MZ and DZ twins, and (3) the probability of cancer is independent between twins with the CS genotype. Estimation was maximum likelihood via a search over allele frequency and two levels of EM algorithms. Models had acceptable or good fits. Variability was estimated using a bootstrap approach, but only 50 replications were feasible. The 94th percentile of bootstrap replications for the estimated fraction of cancers with the CS genotype ranged, over the various genetic models, from 0.16 to 0.45 for prostate cancer, 0.12 to 0.30 for breast cancer, and 0.08 to 0.27 for colorectal cancer. We conclude that genetic susceptibility makes only a small to moderate contribution to the incidence of prostate, breast, and colorectal cancer.     

Assortative mating for anthropometric traits in parents of Punjabi twins

The marital correlations between 97 pairs of parents of Punjabi twins reveal positive phenotypic assortative mating for body traits while almost random mating with respect to cranio-facial traits. There is no evidence of any significant negative assortative mating for any of the 50 traits. The results have been compared with those from other world populations. The data contradict the earlier reported hypothesis that assortative mating is associated with lowered fertility.