[Association study of Trp2 allele polymorphism with degenerative disc disease in a Chinese Han nationality].
OBJECTIVE
To investigate the association between Trp2 allele polymorphism with degenerative disc disease (DDD) in a Chinese Han population.


METHODS
A total of 125 DDD patients (58 males and 67 females, 51.8 +/- 7.6 years old), and 125 controls matched in sex and age (63 males and 62 females, 45.3 +/- 8.3 years old) were recruited in the case-control study. Their peripheral blood samples were collected for DNA isolation. Based on NCBI genebank, the corresponding single nucleotide polymorphisms (snp)-SNP1 (rs7533552) and SNP2 (rs2077871) were identified. Hardy-Weinberg equilibrium was analyzed both in case and control groups. Then the case group was classified into different clinical phenotypes according to severity of degeneration, sole or multi-disc degeneration and different affected discs. Genotyping of all selected SNPs was performed by SNP stream technology. The association analysis between phenotypes and SNPs was conducted. Pairwise linkage disequilibrium was calculated in control population using Haploview 4.0 software.


RESULTS
SNP1 (rs7533552), SNP2 (rs2077871) and corresponding SNP of Trp2 allele were gentyped and both polymorphisms distributed in line with Hardy-Weinberg equilibrium in case and control groups. Allelic frequency of SNP1A, SNP1G, SNP2C and SNP2T (42%, 47%, 88% and 90% respectively) of case group were not significantly different from those of control group (48%, 53%, 88% and 10% respectively, all P > 0.05). Genotypic frequencies of SNP1AA, SNP1AG, SNP1GG, SNP2CC, SNP2CT and SNP2TT in case group were not significantly different from those of control group (all P > 0.05). However there was an association with genotypic frequencies of SNP2 and severity of disc degeneration (chi(2) = 6.920, P = 0.031).


CONCLUSIONS
Trp2 allele is one of risk factors for the development and severity of DDD in a Chinese Han population.
Song
Hai-feng
HF
Department of Spine, People's Hospital of Tianjin, Tianjin 300121, China.
Wu
Zhi-hong
ZH
Fei
Qi
Q
Yan
Jia-zhi
JZ
Liu
Zheng
Z
Zhang
Jian-guo
JG
Li
Shu-gang
SG
Qiu
Gui-xing
GX
D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000208:ethnology / Q000235:genetics*; D019746:Intramolecular Oxidoreductases / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide
D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase