Study on the relationship between vitamin D receptor gene polymorphisms and the susceptibility to children's dental fluorosis of Han nationality / 中国地方病学杂志

ABSTRACT

objective To observe the distribution of vitamin D receptor(VDR)gene polymorphisms in children of Han nationality and investigate the relationship between VDR gene polymorphisms and the susceptibility to children's dental fluorosis of Han nationality.Methods From October of 2008 to March of 2009,a case-control study was conducted among children between 8 and 12 years old with(n=101)and without(n=102)dental fluorosis using Dean method in Guandian countyside of Fengtai county in Anhui province.DNA was extracted from blood samples ofthese children.The Apa I,Bsm I,Fok I and raq I polymorphisms in the VDR gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).The distribution of the genotypes in patients and the control group were analyzed. Results Different genotypes of the VDR gene existed in children of Han nationality with the highest distribution frequency of Aa, bb, Ff, TT, which respectively was 51.7% ( 105/203 ), 89.7% (182/203), 52.7% (107/203), 93.1% (189/203), followed by genotype distribution frequency of aa, Bb, FF, Tt, being 39.9% (81/203),7.9% (16/203),31.5% (64/203) ,6.9% (14/203), respectively. AA,BB, ff, tt distribution frequency was the lowest as follows, 8.4% ( 17/203 ), 2.4% (5/203), 15.8% (32/203),0 (0/203). The frequency distribution of VDR Apa I genotype was AA 7.9% (8/101), Aa 55.4% (56/101), aa 36.7%(37/101) in children with fluorosis, and AA 8.8% (9/102), Aa 48.0% (49/102), aa 43.3% (44/102) in children without fluorosis, respectively. There were no significant differences in the two groups(χ2= 1.13, P > 0.05).The frequency distribution of VDR Bsm I genotype was BB 3.0%(3/101), Bb 5.9%(6/101 ), bb 91.1% (92/101) in children with fluorosis, and BB 2.0% (2/102), Bb 9.8% (10/102), bb 88.2% (90/102) in children without fluorosis, respectively. There were no significant differences in the two groups(χ2 = 0.55, P > 0.05). The frequency distribution of VDR Fok I genotype was FF 28.7%(29/101), Ff 56.4% (57/101), ff 14.9%(15/101) in children with fluorosis, and FF 34.3% (35/102), Ff 49.0% (50/102), ff 16.7% (17/102) in children without fluorosis,respectively. There were no significant differences in the two groups(χ2 = 1.14, P > 0.05). The frequency distribution of VDR Taq I genotype was TT 93.1%(94/101), Tt 6.9%(7/101) in children with fluorosis, and TT 93.1% (95/102), Tt 6.9%(7/102) in children without fluorosis, respectively. The tt genotype was not found. There were no significant differences in the two groups (χ2 = 0.00, P > 0.05 ). Conclusions Different genotypes of the VDR gene existed in children of Han nationality. There were no correlation between VDR Apa I , Bsm I , Fok I , Taq I gene polymorphisms and children's dental fluorosis of Han nationality in this area.