Rebato E, Salces I, Saha R, Sinha M, Susanne C, Hauspie R C, Dasgupta P
Department Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV-EHU), Bilbao, Spain.
Ann Hum Biol. 2005 May-Jun;32(3):339-50. doi: 10.1080/03014460500087857.
Even though some studies have considered that sibling resemblance remains constant throughout the life cycle, several investigations emphasize the importance of age and its interactions with genetic and environmental factors in determining sibling similarity in several bodily traits. In fact, the study of age changes in familial resemblance is of great importance for the analysis of certain sources of variation observed in growth processes.
The study examined sibling resemblance for height, weight and body mass index (BMI) in a mixed longitudinal sample from West Bengal, ages 2-19 years, in order to analyse the variations with age of the sibling resemblance for these phenotypes during growth.
Two hundred and forty-five brothers and 213 sisters from 138 middle-class nuclear families living in a semi-urban area of South Kolkata, India were analysed. The analysis of sibling resemblance was performed through correlations estimated by the maximum-likelihood method. The patterns of different trends of sibling resemblance with age were examined by fitting a cubic non-linear regression to the observed correlations.
The results show clear variations with age in the sibling resemblance for the traits height and weight, though to a lesser extent for BMI. In general, we found the highest correlation values during the period of infancy, a remarkable decrease during puberty, and a trend of increase towards the end of the growth cycle.
The study confirms the effect of age on the degree of similarity among siblings for height, weight and BMI in the sample. The sharp decline of correlation at adolescence can be interpreted in terms of the individual variation in age of reaching the adolescent growth spurt.
尽管一些研究认为兄弟姐妹间的相似性在整个生命周期中保持不变，但多项调查强调了年龄及其与遗传和环境因素的相互作用在决定多种身体特征的兄弟姐妹相似性方面的重要性。事实上，研究家族相似性随年龄的变化对于分析生长过程中观察到的某些变异来源非常重要。
本研究调查了来自西孟加拉邦年龄在2至19岁的混合纵向样本中兄弟姐妹在身高、体重和体重指数（BMI）方面的相似性，以便分析这些表型在生长过程中兄弟姐妹相似性随年龄的变化。
对居住在印度加尔各答南部半城市地区的138个中产阶级核心家庭中的245名兄弟和213名姐妹进行了分析。通过最大似然法估计的相关性来进行兄弟姐妹相似性分析。通过对观察到的相关性拟合三次非线性回归来研究兄弟姐妹相似性随年龄的不同趋势模式。
结果表明，身高和体重特征的兄弟姐妹相似性随年龄有明显变化，不过BMI的变化程度较小。总体而言，我们发现婴儿期的相关性值最高，青春期显著下降，并且在生长周期结束时呈上升趋势。
该研究证实了年龄对样本中兄弟姐妹在身高、体重和BMI方面相似程度的影响。青春期相关性的急剧下降可以用达到青春期生长突增的年龄个体差异来解释。
