Study On Single Nucleotide Polymorphims Of Genes Related To Idiopathic Short Stature

Objective:ISS (idiopathic short stature) is a multi-gene disease. Its etiopathogenisis is not yet clear, and it's a heterogeneous disease, in which genetic factors play a major role. Its main clinical manifestation is pituitary growth hormone insulin-like growth factor 1 axis and bone growth plate dysfunction. Based on the above understanding, this study will conduct a preliminary discussion about ISS related SNP locus polymorphism in GH-IGF-1 growth plate axis.Methods:1,DNA from 70 ISS cases was extracted by Phenol chloroform method, and its purity was detected by using 1% agarose gel electrophoresis.2,Authers selected five tSNP of IHH and GHR gene and genotyped allele frequencies of the 70 ISS cases'DNA in Illumina Goldengate genetic analysis platform.3,The results of the genotypeing were checked with Hardy-Weinberg genetic equilibrium tests to determine whether the genotype frequencies have genetic equilibrium, and represented general population.4,It was compared that frequency distribution of the allele, genotype and the dominant or recessive model's genotype withχ2 test between the 70 ISS cases and 378 normal controls,and the analytical results of genotype and allele were showed with the relative risk odds ratio (Odds ratio, OR) and 95% confidence interval (CI).5,Authers measured the height, sitting height, arm span, weight of the 70 ISS cases,and calculate the bone age with Ye's bone age scoring system; then analyzed the clinical indicators of each group by the Pearson correlation.6,In 70 ISS cases,authers compared the clinical indicators of different genotype,analyzed two groups by t test, three groups by one-way ANOVA.7,In the meantime,authers selected 40 normal children together with the 70 ISS cases,then detected their serum IGF-1, IGFBP3 levels with enzyme-linked immunosorbent assay (ELISA), at last compared the two groups'serum IGF-1, IGFBP3 levels, analyzed its diagnosis value for ISS.Results:1,The genotype and allele frequency change of IHH locus rs3099 was related to ISS, and AA genotypes and A allele are the predisposing types.2,The genotype and allele frequency change of GHR locus rs12515480 was related to ISS, and AA genotypes and A allele are the predisposing types.3,The levels of IGF-1 in ISS children was lower than normal children controls, but the levels of IGFBP3 in ISS children were higher than normal children controls;the IGF-1, IGFBP3 levels between each genotypes of locus rs12515480 have no difference.4,In ISS cases,the ratio of low leg length to sitting height was positively correlated to their genetic target height,it suggested that ISS children have reduced potential of lower limb growth.5,The ratio of low leg length to sitting heigh between genotypes of IHH gene loci rs3099 was not significantly defferent;it indicated that IHH gene may have greater role in prompting limbs growth than in the trunk.Conclusion:1,ISS associated with the SNP of GHR and IHH gene loci,is a multi-gene and heterogeneous disease.2,As the third generation of genetic markers, SNP became one of the most powerful tool for ISS and other genetic disease research.3,Apart from the abnormal growth hormone secretion in children with ISS, we also should pay attention to their bone growth plate functional damage...