A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors
A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors
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DOI：
10.1016/j.ajhg.2009.09.006
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发表时间：
2009-10-09
影响因子：
9.8
通讯作者：
Oota, Hiroki
中科院分区：
文献类型：
--
作者：
Kimura, Ryosuke;Yamaguchi, Tetsutaro;Oota, Hiroki
铲形的上门牙是亚洲和美洲土著人口的共同特征，但在非洲和欧洲人口中罕见或不存在。像其他常见的牙齿特征一样，与牙齿铲动有关的遗传多态性尚未得到澄清。在功能失调突变导致少汗性外胚层发育不良的外胚层A受体（EDAR）中，存在一种非同构衍生变体1540C (rs3827760)，其地理分布与牙齿铲的相似。最近有报道称，这种等位基因与亚洲人特有的头发厚度有关。我们的目的是澄清EDAR 1540C是否也与牙齿形态有关。为此，我们测量了东京和咲岛两个日本人群的冠直径和牙齿铲齿等级，并分析了牙齿性状与EDAR基因型之间的相关性。个体中EDAR 1540C等位基因的数量与铲牙等级密切相关（p = 7.7 × 10(-10)）。该等位基因的作用是加性的，解释了铲级总方差的18.9%，相当于先前报道的性状遗传力的约四分之一。对于个人层面度量数据的数据缩减，我们应用了主成分分析，得出了PCI-4，对应于四种牙齿尺寸模式；这一结果表明多种因素参与了牙齿形态的形成。1540C等位基因也显著影响PC1 （p = 4.9 x 10(-3)）和PC2 (p = 2.6 x 10(-3))， PC1表示牙齿总尺寸，PC2表示中远端直径与颊舌直径之比。
Shovel shape of upper incisors is a common characteristic in Asian and Native American populations but is rare or absent in African and European populations. Like other common dental traits, genetic polymorphisms involved in the tooth shoveling have not yet been clarified. In ectodysplasin A receptor (EDAR), where dysfunctional mutations cause hypohidrotic ectodermal dysplasia, there is a nonsynonymous-derived variant, 1540C (rs3827760), that has a geographic distribution similar to that of the tooth shoveling. This allele has been recently reported to be associated with Asian-specific hair thickness. We aimed to clarify whether EDAR 1540C is also associated with dental morphology. For this purpose, we measured crown diameters and tooth-shoveling grades and analyzed the correlations between the dental traits and EDAR genotypes in two Japanese populations, inhabitants around Tokyo and in Sakishima Islands. The number of EDAR 1540C alleles in an individual was strongly correlated with the tooth-shoveling grade (p = 7.7 x 10(-10)). The effect of the allele was additive and explained 18.9% of the total variance in the shoveling grade, which corresponds to about one-fourth of the heritability of the trait reported previously. For data reduction of individual-level metric data, we applied a principal-component analysis, which yielded PCI-4, corresponding to four patterns of tooth size; this result implies that multiple factors are involved in dental morphology. The 1540C allele also significantly affected PC1 (p = 4.9 x 10(-3)), which denotes overall tooth size, and PC2 (p = 2.6 x 10(-3)), which denotes the ratio of mesiodistal diameter to buccolingual diameter.