Gene therapy: ethical issues

To discern the ethical issues involved incurrent gene therapy research, to explore theproblems inherent in possible future genetherapies, and to encourage debate within thescientific community about ethical questionsrelevant to both, we surveyed American Societyof Human Genetics scientists who engage inhuman genetics research. This study of theopinions of U.S. scientific experts about theethical issues discussed in the literature ongene therapy contributes systematic data on theattitudes of those working in the field as wellas elaborative comments. Our survey finds thatrespondents are highly supportive of thepotential use of somatic cell gene therapy tocure serious diseases in adults and children aswell as prospective offspring. A clearmajority, however, believe that using suchgenetic techniques for enhancement purposes isunacceptable. Delineating the line betweendisease/disorder and improvement/enhancementposes a problem not easily resolved and oneconducive to the growth of slippery-slopeapprehensions. The majority of respondents alsoadvocate germ-line therapy, in theory at least,and under similar restrictions, but theyrecognize the roadblock that the existence ofunanticipated negative consequences currentlypresents. Another complex matter involvestrying to determine appropriate reasons forchoosing target diseases for research, forwhich the dichotomy between rare single-geneand common multifactorial diseases reveals anongoing dilemma.     

MTHFR and ACE gene polymorphisms and risk of vascular and degenerative dementias in the elderly

Focal lacunar infarctions due to cerebral small vessel atherosclerosis or single/multiple large cortical infarcts lead to vascular dementia, and different genes and environmental factors have been implicated in causation or aggravation of the disease. Previous reports suggest that some of the risk factors may be common to both vascular as well as degenerative dementia. Among genetic factors, role of angiotensin converting enzyme (ACE) and methylene-tetrahydrofolate reductase (MTHFR) genes as putative risk factors has been examined but the outcome of these studies remain inconclusive. Present study attempted to see the importance of ACE alu insertion/deletion and MTHFR C677T polymorphisms as genetic predisposers to dementia. The study comprised of 80 vascular dementia patients, 90 degenerative dementia patients and 170 age matched controls. All were genotyped for ACE, MTHFR and APOE polymorphisms using PCR-RFLP method. Frequency of ACE D allele was seemingly high in dementia cases (26.7%) when compared to controls (11.2%). However, after adjusting for age and APOE E4^*, none of the ACE alleles showed good correlation. MTHFR genotypes or alleles also did not show any correlation. Our study suggests no true correlation of ACE or MTHR genes with dementia in elderly.     

COMT基因rs6267多态性与母亲教养行为对青少年身体攻击和关系攻击的交互作用

遗传与环境如何交互作用影响儿童青少年的攻击行为是当前攻击研究中的重要前沿课题之一。近年来, 分子遗传学关于人类攻击的研究已拓展到对不同攻击亚类(身体攻击和关系攻击)的遗传基础的探讨。本研究运用问卷法与DNA分型技术, 对1258名儿童进行为时4年(四年级—七年级)的追踪调查, 考察COMT基因rs6267多态性与母亲教养行为对青少年身体攻击和关系攻击的交互作用以及性别在其中的调节作用。结果发现, COMT基因rs6267多态性与母亲教养行为仅交互作用于男青少年的身体攻击, 母亲教养行为显著预测GG 基因型男青少年的身体攻击, 但对T等位基因男青少年身体攻击的预测作用并不显著。COMT基因rs6267多态性与母亲教养行为对青少年关系攻击的交互作用不显著。本研究结果表明, 身体攻击和关系攻击具有不同遗传基础和发生机制。     

父母教养行为与青少年早期抑郁的关系：多基因与负性生活事件的调节作用

以745名青少年为被试,采用多基因×多环境设计,考察COMT Val158Met、5-HTR1A C-1019G和BDNF Val66Met基因多态性的多基因累加得分与负性生活事件在父母教养行为与青少年早期抑郁之间的调节作用及其性别差异。结果发现,多基因累加得分与负性生活事件仅能显著调节父亲积极教养行为对青少年抑郁的预测作用,且该调节作用只存在于男青少年群体中。研究结果丰富了抑郁的多基因遗传机制研究,为制定青少年早期抑郁的干预措施提供了理论依据。     

人类基因编辑技术对运气平等主义的挑战及应对

运气平等主义区分选择和运气,强调具体责任原则,认为个体选择导致的不利处境不应该得到社会补偿。人类基因编辑技术的高速发展使得自由主义优生得以可能,父母可以自主设计下一代的基因构成,并为此承担责任。然而,由于个体选择的是定义人类自然本性的生物素质,具体责任原则在人类基因编辑技术实践中引发新的挑战：打破分配正义预设;难以厘清责任归属;破坏责任承担自由意志;加剧社会不平等。为了使人类基因编辑技术更好地促进社会正义,需要重申平等对待原则,加强责任伦理,以及完善社会保障机制。

     

孕前耳聋基因筛查伦理问题分析及应对措施

耳聋基因筛查是预防遗传性耳聋的重要手段,日益受到社会关注。然而,其应用过程中伴随着诸多伦理问题：价格较高导致资源分配不均,部分人群无法公平享受此项筛查服务;检测结果的不准确性侵犯受检者的健康权;知情同意落实不到位,受检者权益难以保障;胎儿选择权引发伦理争议;隐私泄露风险不容忽视;专职遗传咨询人才匮乏,咨询质量参差不齐;耳聋基因歧视现象亦存在。提出应该加大社会投入、保障受检者的健康权、规范知情同意、尊重受检者选择权、保护受检者隐私权、加强遗传咨询师队伍建设、提高公众认知度,消除基因歧视应对措施。