Effects of an Asian-specific nonsynonymous EDAR variant on multiple dental traits.
Dental morphology is highly diverse among individuals and between human populations. Although it is thought that genetic factors mainly determine common dental variations, only a few such genetic factors have been identified. One study demonstrated that a nonsynonymous single-nucleotide polymorphism (370V/A, rs3827760) in the ectodysplasin A receptor gene (EDAR) is associated with shoveling and double-shoveling grades of upper first incisors and tooth crown size. Here, we examined the association of EDAR 370V/A with several dental characters in Korean and Japanese subjects. A meta-analysis that combined analyses of Korean and Japanese subjects revealed that the Asian-specific 370A allele is associated with an increase in the grades of shoveling and double shoveling, as previously found. We also showed a highly significant association between EDAR 370V/A genotype and crown size, especially mesiodistal diameters of anterior teeth. Moreover, we found that the 370A allele was associated with the presence of hypoconulids of lower second molars. These results indicated that the EDAR polymorphism is responsible, in part, for the Sinodonty and Sundadonty dichotomy in Asian populations, and clearly demonstrated that the EDAR polymorphism has pleiotropic effects on tooth morphology. As the 370A allele is known to be a most likely target of positive selection in Asian populations, some phenotypes associated with the variant may be 'hitchhiking phenotypes', while others may be actual targets of selection.
Department of Orthodontics, Pusan National University Dental Hospital, Yangsan, Korea.
Jeong-Heuy
JH
Park
Tetsutaro
T
Yamaguchi
Chiaki
C
Watanabe
Akira
A
Kawaguchi
Kuniaki
K
Haneji
Mayako
M
Takeda
Yong-Il
YI
Kim
Yoko
Y
Tomoyasu
Miyuki
M
Watanabe
Hiroki
H
Oota
Tsunehiko
T
Hanihara
Hajime
H
Ishida
Koutaro
K
Maki
Soo-Byung
SB
Park
Ryosuke
R
Kimura
D000483:Alleles; D044466:Asian People / Q000235:genetics*; D053339:Edar Receptor / Q000235:genetics*; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology; D008963:Molar / Q000033:anatomy & histology; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D014070:Tooth / Q000033:anatomy & histology*; D019228:Tooth Crown / Q000033:anatomy & histology
C506008:EDAR protein, human; D053339:Edar Receptor