Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America.
Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA, United States of America.
PLoS One. 2022 Dec 28;17(12):e0279202. doi: 10.1371/journal.pone.0279202. eCollection 2022.
Mild proximal-to-distal tapering of the fingers is a relatively common trait in humans. When more extreme, finger tapering is a feature observed in many genetic syndromes. The range of variation for finger tapering in the general population is not well understood, and sex differences in the degree of tapering, while suspected, have not been documented. Part of the difficulty is a lack of objective methods to evaluate finger tapering. In the present report, we developed a tapering index based on linear measures derived from digital hand scans. We measured this index in a sample of 166 male and 166 age-matched female adults. We then looked at correlations both among fingers and with demographic and anthropometric variables, followed by tests for sex differences. We observed weak correlations between tapering and age, height and weight. Correlations between pairs of fingers tended to be more in the moderate range and were highest among the middle three fingers (ranging from 0.34 to 0.64). Tapering tended to increase slightly moving radially across the hand from the fifth finger to the second finger. Males showed less tapering than females for all fingers, with statistically significant differences involving the left second finger (p = 0.003), left fifth finger (p< 0.001), right second finger (p = 0.038), and right fourth finger (p = 0.021). Finally, we established baseline norms for both males and females out to three standard deviations. Our results indicate that finger tapering is present, to some degree, in most of the population and that the trait can be measured using a relatively simple and non-invasive method. These findings may have relevance for fields as diverse as medical genetics, forensics, and industrial design.
手指从近端到远端逐渐变细是人类较为常见的特征。当手指变细程度更为明显时,则是许多遗传性综合征的特征之一。目前,人们对人群中手指变细的变异范围还缺乏了解,虽然怀疑手指变细存在性别差异,但尚未有相关记载。部分原因在于缺乏评估手指变细的客观方法。在本报告中,我们基于手部数字扫描得出的线性测量值,开发了一种变细指数。我们在 166 名男性和 166 名年龄匹配的女性成年人样本中测量了该指数。然后,我们研究了手指之间以及与人口统计学和人体测量学变量之间的相关性,随后进行了性别差异测试。我们观察到变细指数与年龄、身高和体重之间存在弱相关性。各手指之间的相关性趋于中等范围,中间三个手指(从第五指到第二指)之间的相关性最高(范围为 0.34 至 0.64)。从第五指到第二指,手指沿手的桡侧逐渐变细。与女性相比,所有手指的男性变细程度都较小,其中左手第二指(p = 0.003)、左手第五指(p < 0.001)、右手第二指(p = 0.038)和右手第四指(p = 0.021)的差异具有统计学意义。最后,我们为男性和女性建立了三个标准差的基本规范。我们的研究结果表明,大多数人群中存在一定程度的手指变细,该特征可以使用相对简单且非侵入性的方法进行测量。这些发现可能与医学遗传学、法医学和工业设计等多个领域相关。