基于生物信息学的肥厚型心肌病易感基因TNNC1单核苷酸多态性致病表型分析

肥厚型心肌病(HCM)是一种常见的遗传性心脏病,是青少年及年轻运动员心源性猝死的最主要原因之一,其分子遗传学基础为基因突变。TNNC1是HCM的重要致病基因之一,目前仅发现其少量非同义单核苷酸多态性(nsSNPs)位点与HCM发病相关,但该基因其他nsSNPs数量较多,结合临床进行实验遗传检测其基因型与表型的关系,工作量巨大,尚不可行。因此,采用生物信息学方法,从dbSNP数据库中筛选出TNNC1基因全部的nsSNPs,联合4款(Mutation Taster、PolyPhen-2、PhD-SNP和MutPred)专业软件,进行有害性分级筛选和致病关联预测,最后进行突变蛋白三维结构建模及可视化分析。结果显示,首次从TNNC1基因102个nsSNPs位点中预测出疾病相关的18个(G159D、S69R、P52R、D149G、D3V、G140E、N51K、D151V、M47R、G110C、A23D、G140R、K158N、C35Y、R147C、L48P、F74C和V44G)高风险nsSNPs。基于生物信息学方法,以TNNC1基因的nsSNPs为示范,分析其nsSNPs与疾病表型的关系,这为其他遗传疾病致病基因nsSNPs的关联分析打下理论研究基础,具有重要的参考价值。     

基因组拷贝数变异测序与染色体核型分析在胎儿遗传学诊断中的比较

目的比较基因组拷贝数变异测序(CNV-seq)技术和染色体核型分析和在产前胎儿遗传学诊断中的应用价值。方法收集来我院有产前诊断指征进行羊水穿刺的259例孕妇,取材后,送检染色体核型分析和CNV-seq,比较两种方法在产前诊断中的优缺点。结果259例标本中,共诊断异常染色体核型及微缺失微重复23例,总阳性诊断率8.88%(23/259),CNV-seq结果显示,共有22例染色体拷贝数异常(12例三体+9例微缺失微重复+1例三倍体),检出率为8.49%;染色体核型分析结果显示为:17例染色体异常(12例三体+3例结构异常+1例嵌合型+1例三倍体),检出率为6.56%。此外还检出染色体多态7例。结论CNV-seq与染色体核型分析对于染色体非整倍体的检测效力一致,CNV-seq能检测染色体微缺失微重复,染色体核型分析则能诊断出三体具体核型,在怀疑性染色体异常时,建议行两者联合检测。     

NUDT15 is a key genetic factor for prediction of hematotoxicity in pediatric patients who received a standard low dosage regimen of 6-mercaptopurine

6-Mercaptopurine (6-MP) is commonly used for treatment of acute lymphoblastic leukemia (ALL). The incidence of hematotoxicity caused by this drug is quite high in Asians even using a standard low dosage regimen. The present study was aimed to elucidate the impact of thiopurine S-methyltransferase (TPMT), a nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15), inosine triphosphatase (ITPA) and ATP Binding Cassette Subfamily C Member 4 (ABCC4) polymorphisms on hematotoxicity in pediatric patients who received a standard low starting dose of 6-MP. One hundred and sixty-nine pediatric patients were enrolled and their genotypes were determined. Patients who carried NUDT15¹3 and NUDT15¹2 genotypes were at a 10–15 fold higher risk of severe neutropenia than those of the wild-type during the early months of the maintenance phase. Risk of neutropenia was not significantly increased in patients with other NUDT15 variants as well as in patients with TPMT, ITPA or ABCC4 variants. These results suggest that NUDT15 polymorphisms particularly, NUDT15¹3 and NUDT15¹2, play major roles in 6-MP-induced severe hematotoxicity even when using a standard low dosage of 6-MP and genotyping of these variants is necessary in order to obtain precise tolerance doses and avoid severe hematotoxicity in pediatric patients.     

The influence of polymorphisms in the drug transporter,ABCB1 on the toxicity of glucocorticoids in Saudi children with acute lymphoblastic leukaemia

Background

Glucocorticoids play essential roles in the treatment of childhood acute lymphoblastic leukaemia (ALL); however, treatment with these agents can result in severe side-effects. This study, the first of its kind in a Saudi population, investigates associations of ABCB1 gene polymorphisms (pharmacodynamics and pharmacokinetic) with the development of toxicity and side effects (glucose abnormality, liver toxicity and infection) in a small population of Saudi children with ALL.

Does CETP rs5882, rs708272, SIRT1 rs12778366, FGFR2 rs2981582, STAT3 rs744166, VEGFA rs833068, IL6 rs1800795 polymorphisms play a role in optic neuritis development?

Objectives: Optic neuritis (ON) is defined as inflammation of the optic nerve, which is mostly idiopathic. However, it can be associated with various causes (demyelinating lesions, autoimmune disorders, infectious and inflammatory conditions). Inflammatory demyelinating disorder of the optic nerve can be associated with multiple sclerosis. It is thought that CETP, SIRT1, FGFR2, STAT3, VEGFA and IL6 genes play a key role in this autoimmune inflammatory disease. The aim of our study was to determine if the frequency of the CETP, SIRT1, FGFR2, STAT3, VEGFA and IL6 gene polymorphisms have an influence on the development of acute ON.

Methods: The study enrolled patients with ON and a random sample of healthy population. The genotyping test of the CETPrs5882,rs708272, SIRT1rs12778366, FGFR2rs2981582, STAT3rs744166, VEGFArs833068, IL6rs1800795 polymorphisms was carried out using the RT-PCR method.

Results: Our study determined that the G/A genotype of CETPrs708272 was associated with two-fold-decreased odds of ON development under the codominant (OR = 0.495;95%CI:0.256–0.959) and overdominant (OR = 0.501;95%CI:0.280–0.895) models. Also, each allele C at VEGFArs833068 was associated with 1.7-fold increased odds of ON development under the additive model (OR = 1.733;95%CI:1.148–2.615). Furthermore, IL6 rs1800795 G/G genotype was associated with increased odds of ON development under the codominant (OR = 2.869;95%CI:1.280–6.434) and recessive (OR = 2.315;95%CI:1.251–4.285) models.

Conclusions: We revealed that the genotypes of CETPrs708272 G/A, IL6rs1800795 G/G, and each allele C at VEGFArs833068 were associated with ON. CETPrs708272 G/G genotype was associated with decreased by 62% odds of ON with MS development under the recessive (OR = 0.379;95%CI:0.155–0.929; p = .034) model.     

Complexities of Cardiac Genetic Testing

This study explored the lived experiences of family members who were referred to a cardiogenetics clinic after the loss of a family member to sudden cardiac death. Participants revealed many health concerns and emotions, including disappointment, guilt, ambivalence, blame, and fear of loss. Understanding these findings and their potential effect on the family members may provide nurse practitioners with the ability to improve the quality of care that is offered to family members after sudden cardiac death and further the knowledge for genetic testing and disease management.