| Objective:To analyse the sequence of coding region of bone morphogenetic protein-2(BMP-2) gene,study the gene mutation or polymorphism in the peripheral blood of patients with spinal fusion,and investigate the relationship between abnormal expression of BMP-2 and postoperative bony fusion,so as to find out the genetic factors on bony fusion after bone transplantation.Methods:Totally 150 patients,of which 70 cases were received anterior cervical interbody fusion with autogenous iliac bone;80 cases were carried out posterior lumbar intertransverse bony fusion with vertebra,and 145 normal controls were included in this study.DNA was extracted from the venous blood and identified by single strand conformation polymorphism analysis of polymerase chain reaction products(PCR-SSCP),denaturing high-performance liquid chromatography(DHPLC) and direct sequencing to detect the abnormal expression of Exonl,Exon2 and mature peptide gene of BMP-2,to find out the mutation rate and distribution frequency of polymorphic site;X-ray examination were done after operation at 1 week,3,6,12 months in all the patients,and according to the lateral and dynamic view to evaluate the degree of bony fusion;Database was established and SPSS software was used to find out the correlation between abnormal expression of BMP-2 and bony fusion.Results:In all the 295 cases,106 patients(56 in case group,and 50 in control group) were found the A/G heterozygote at the position 268 of Exon2,and 189 cases(94 in case group,and 95 in control group) were G/G homozygote at the same positon of Exon2;In all the cases,no A/A homozygote as reported in the Genebank was found and no abnormal expression was detected in Exonl and mature peptide gene of BMP-2.Degree of bony fusion was as follows:In the cervical group,the fast group was 22 cases,medium was 39 cases,slow was 9 cases,which were correlated with the distribution frequency of A/G and G/G,and the distribution frequency of A/G in the fast group was higher than that in medium and slow group;In the lumbar group,the fast group was 20 cases,medium was 44 cases,slow was 16 cases,which had no relationship with the distribution frequency of A/G and G/GConclusions:In our experiment,an polymorphic site is found in the coding region of BMP-2 gene of both the patient with spinal fusion and healthy people,and its distribution frequency is correlated with the postoperative bony fusion degree in the anterior cervical interbody fusion with autogenous iliac bone,and not correlated with that in posterior lumbar intertransverse bony fusion with vertebra.Several aspects should be considered,for example,more influencing factors will effect the intertransverse bony fusion degree than intervertebral fusion,and the evaluation standard is also more complicate in the intertransverse bony fusion,which should be investigated further.The results obtained have provided a theory foundation for the further study of genetic factors on bony fusion after bone transplantation. |
