ALBERT

Description: Background: TBX1 and CRKL haploinsufficiency is thought to cause the cardiac phenotype of the 22q11.2 deletion syndrome. However, few unequivocal mutations of TBX1 and CRKL have been discovered in isolated conotrucal heart defects (CTDs) patients. The aim of the study was to screen the mutation of TBX1 and CRKL in isolated CTDs Chinese patients without 22q11.2 deletion and identify the pathomechanism of the missense mutations. Methods: We enrolled 199 non-22q11.2 deletion patients with CTDs and 139 unrelated healthy controls. Gene sequencing were performed for all of them. The functional data of mutations were obtained by in vitro transfection and luciferase experiments and computer modelling. Results: Screening of the TBX1 coding sequence identified a de novo missense mutation (c.385G [rightwards arrow] A; p.E129K) and a known polymorphism (c.928G [rightwards arrow] A; p.G310S). In vitro experiments demonstrate that the TBX1E129K variant almost lost transactivation activity. The TBX1G310S variant seems to affect the interaction of TBX1 with other factors. Computer molecular dynamics simulations showed the de novo missense mutation is likely to affect TBX1-DNA interaction. No mutation of CRKL gene was found. Conclusions: These observations suggest that the TBX1 loss-of-function mutation may be involved in the pathogenesis of isolated CTDs. This is the first human missense mutation showing that TBX1 is a candidate causing isolated CTDs in Chinese patients without 22q11.2 deletion.

Description: Background: CYP17A1 gene encodes P450c17 proteins, which is a key enzyme that catalyzes the formation of sex hormones. Many clinical studies showed that sex hormones levels play an important role in the pathogenesis of coronary artery disease (CAD). However, the relationship between CYP17A1 genetic polymorphisms and CAD remains unclear. The aim of this study was to investigate the association of CYP17A1 genetic polymorphisms with CAD in a Han population of China. Methods: A total of 997 people include 490 patients and 507 controls were selected for the present study. Five single-nucleotide polymorphisms (SNPs) (rs4919686, rs1004467, rs4919687, rs10786712, and rs2486758) were genotyped by using the real-time PCR (TaqMan) method. Results: For men, the rs10786712 was found to be associated with CAD in a recessive model (P = 0.016), after adjustment of the major confounding factors, the significant difference was retained (OR = 1.644, 95% confidence interval [CI]:1.087-2.488, P = 0.019). For women, the rs1004467 was also found to be associated with CAD in a dominant model (P = 0.038), the difference remained statistically significant after multivariate adjustment (OR = 1.623, 95% CI: 1.023-2.576, P = 0.040). The distribution of rs4919687 genotypes showed a significant difference between CAD and control participants in a recessive model (P = 0.019), the significant difference was retained after adjustment for covariates (OR = 0.417, 95%CI: 0.188-0.926, P = 0.032). Conclusion: Rs1004467, rs4919687, rs10786712 of CYP17A1 gene are associated with CAD in Han population of China. The TT genotype of rs10786712 could be a protective genetic marker of CAD in men. The CC genotype of rs1004467 and the AA genotype of rs4919687 could be risk genetic markers of CAD in women. However, large sample size study including other SNPs of CYP17A1 should be performed in future studies.