Mutation Analysis Of Hairy-and-enhancer-of-split-7Gene Exons In Patients With Congenital Scoliosis

Chapter1Mutation Analysis of Hairy-and-Enhancer-of-Split-7Gene Exons in Patients with Congenital ScoliosisObjective:To identify whether the mutation of Hairy-and-Enhancer-of-Split-7(HES7) gene exons were involved in the pathogenesis of congenital scoliosis (CS) in a Chinese Han population.Methods:From Jun.2009to Dec.2010, sixty sporadic and non-syndromic CS patients (including23males and37females, averagely aged12.9±4.4years) who were Chinese Han population, had complete radiologic data and underwent surgery constituted case group, and80normal controls (including32males and48females, averagely aged13.7±3.2years) who were also Chinese Han population constituted control group in our study. Genomic DNA was extracted from peripheral blood, and the sequences of four HES7exons(Exonl-4) were amplified by premiers we designed, then the target PCR products were purified. Sequencing analysis of purification products was applied, and the sequencing results of two groups were compared with each other by MegAlign of DNAstar software. And the sequencing results were also compared with sequences published by NCBI to detect the gene mutation of four exons of HES7gene in both groups.Results:The sequences of Exonl and Exon4of HES7gene in CS group and normal control group were in accordance with that of the gene bank. G/A polymorphism was found in the81st site of Exon2in both CS group and normal control group, and the difference of the distribution frequency of the polymorphism between two groups was not significant (P=0.727). Moreover, T/C polymorphism was found in the37th site of Exon3in both CS group and normal control. group, and the difference of the distribution frequency of this polymorphism between two groups was also not significant (P=1.000).Conclusions:No exon mutation of HES7gene was found in sporadic and non-syndromic CS in Chinese Han population. The exon mutation of HES7gene may not be involved in the pathogenesis of sporadic and non-syndromic CS in Chinese Han population. Chapter2Contributions of vertebral and disc wedging to Cobb angle in adolescent idiopathic scoliosis with different curve pattern:radiographic discrepancy and clinical significanceObjectives:To investigate the difference in contribution to Cobb angle between vertebral and disc wedging in adolescent idiopathic scoliosis (AIS) with different curve pattern or various severity and to explore the significance.Methods:Form Jan.2007to Jun.2009, One hundred and ten single curve pattern AIS patients were divided into three groups according to the curve pattern:39patients with a major thoracic curve (Group A),33with a thoracolumbar curve (Group B) and38with major lumbar curve (Group C). According to the Cobb angle, patients in each group were subdivided into two subgroups:Cobb angle<40°and Cobb angle≥40°. Every wedging angle of discs and vertebrae in the whole major curve was measured, and its proportion to the Cobb angle was calculated (wedging percentage), respectively.Results:The average age, Cobb angle and Risser sign of all patients was13.6±1.9years,34.4±10.5°and2.4±1.7,respectively. No difference of the average age, Cobb angle and Risser sign was observed among three groups (P>0.05). The wedging angle and wedging percentage of vertebrae were significantly larger than those of discs in patients of Group A (21.9±5.6°vs13.7±5.9°, and62.3%vs37.7%, P<0.001),and the converse results were observed in patients of Group B and Group C (24.1±9.2°vs10.4±3.8°,69.0%vs31.0%, P<0.001; and25.1±7.2°vs7.7±2.4°,76.6%vs23.4%, P<0.001).The wedging angle of vertebrae and discs in patients with Cobb angle≥40°were significantly larger than that of patients with Cobb angle<40°(P<0.001).Along with the increase of Cobb angle, vertebral wedging still played a major role of contribution to Cobb angle in patients of Group A, while disc wedging accounted for the main part in those of Group B and Group C. Additionally, the wedging angle of apical vertebrae was linearly correlated with the Cobb angle in each group (P<0.001).Conclusion:Various vertebral and disc wedging exist in adolescent idiopathic scoliosis no matter what type of curve patterns. The main contribution to the Cobb angle in the thoracic region was the wedging of vertebrae rather than discs, the converse was found in the thoracolumbar and lumbar curves. These indicate different biomechanics with regard to pathogenesis of scoliosis in various curve patterns. Chapter3Risk factors of thoracic curve decompensation after anterior selective fusion in idiopathic scoliosis with major thoracolumbar/lumbar curveObjectives:To investigate the incidence of thoracic curve decompensation or proximal adding-on phenomenon after anterior selective fusion of thoracolumbar/lumbar curve in Lenke type5C adolescent idiopathic scoliosis (AIS), and to identify its risk factors.Methods:Lenke type5C AIS patients with a Cobb angle of40-80degrees treated with anterior selective fusion were recruited in this retrospective study. All patients had a minimum2-year postoperative follow-up. The patients were grouped according to the relationship between the upper instrumented vertebrae (UIV) and the upper end vertebrae (UEV), the patients’Risser sign and the relationship between UIV and Cl plumb line (C7PL). The radiographic data of the patients were compared between patients with and without proximal adding-on, and the incidence of proximal adding-on was analyzed in terms of determination of UIV and Risser sign to identify the risk factors of this phenomenon.Results:One hundred and thirty patients were included in this study, and11patients were identified with proximal adding-on, thus the incidence of it was8.5%. The average age, Cobb angle and Risser sign of all patients was14.8±1.6years,45.6°±5.9°of major thoracolumbar/lumbar curve (TL/L),25.4±7.4°of proximal thoracic curve (PT) and3.6±1.1, respectively. At last follow-up postoperatively, the average Cobb angle of TL/L and PT was8.7±3.5°and11.4±4.8°, respectively. The average Risser sign of patients with adding-on (2.4±1.6) was obviously lower than that of patients without (3.7±1.0), and the difference was significantly (P=0.018). Moreover, the incidence of adding-on in Grade0to1(37.5%) was higher than that of Grade2to3(12.1%) and Grade4to5(4.5%). In addition, the incidence of adding-on in UIV lower than UEV group (20.6%) was obviously higher than that of UIV higher than or equal to UEV group (4.7%). The incidence of adding-on for patients with C7PL falls away from UIV (19.5%) were obviously higher than that of patients with C7PL falls between the pedicle and lateral margin of UIV(3.6%) and between bilateral pedicles of UIV (3.0%). Each group shows significant difference for the incidence of adding-on by Fisher’s Exact Test (P<0.05).Conclusions:There exists the risk of proximal adding-on phenomenon, with a not low rate, after anterior selective fusion for major TL/L curve AIS. The determination of UIV relative to UEV and the skeletal maturity of the patient are the two factors closely associated with the presence of such a phenomenon.