基于高通量测序的染色体微缺失/微重复产前诊断新技术研究

Chromosome micro-deletion/duplication is an important cause of human birth defects. Prenatal genetic diagnosis is the most efficient prevention strategy. Though the current arrayCGH systems can efficiently detect chromosome micro-deletion/duplication, they were both expensive and system closed monotechnics, reducing their clinilcal value. Low-depth Massive Parallel Seqencing(LD-MPS) was supposed to be able to diagnose chromosome micro-deletion/duplication according to it's unique sequencing features. In our previous study, we performed LD-MPS analysis on ten samples of micro-deletion/duplication at a sequencing condition of bi-directional, 50bp length,1X depth. The preliminary results suggested LD-MPS will be a promising micro-deletion/duplication detection technology with further improvements. Based on these date, we will systematically improve the detection efficiency and decrease the test cost by adjuting the experiment flow and date analysis modeling in the next step. We will also investigate the feasibility and clinical value of LD-MPS in the micro-deletion/duplication detection through prospective clinical study. So far there is on research report on prenatal diagnosis of chromosome micro-deletion/duplication using LD-MPS, thus this study have remarkable creativity and may provide a powerful inexpensive technique for the prevention of birth defect due to micro-deletion/duplication.

染色体微缺失/微重复是先天缺陷重要病因之一，产前诊断是有效的干预手段。ArrayCGH技术尽管可实现基因组高分辨率检测，但存在价格昂贵、技术理论单一、体系封闭等缺陷。前期研究中，我们基于高通量平行测序技术(MPS)超高通量DNA单分子的随机测序原理，建立了一种可检测微缺失/微重复的低深度平行测序技术(LD-MPS)；采用50bp双向、1X测序深度策略,对10例染色体微缺失/微重复胎儿样本进行LD-MPS检测，预实验取得初步成功。本研究拟进一步系统分析论证该技术可行性，通过扩大检测标本量、优化完善实验流程和系统设置，以提高检测效果并降低检测成本；将采用前瞻性临床研究策略，评估该技术在先天缺陷产前遗传学诊断中应用价值。目前未见LD-MPS进行产前染色体微缺失/微重复诊断的系统研究报道，本研究具有较强创新性，将可能为先天缺陷的防治提供一种高效、廉价、开放的新型遗传学检测技术。

.染色体微缺失/微重复产前诊断是人类先天缺陷防治的重要手段之一。现有的全染色体微缺失/微重复检测技术仅有arrayCGH技术，存在价格昂贵、技术理论单一、体系封闭等缺陷，临床急需发展新型检测技术。..本项目基于本实验室已有的arrayCGH平台，建立并扩大了染色体微缺失/微重复样本库资源，共计200余例；在此基础上开发建立并优化了基于低深度高通量平行测序技术的染色体微缺失/微重复产前诊断新技术LD-MPS，CNV检测分辨率达到100Kb，检测成本显著降低；我们进行了临床样本的平行检测以评估该新技术的实际应用效果和临床价值，共检测产前样本229例，染色体异常检出率31%，其中异倍体检出率22.3%，致病性拷贝数变异(pCNV)检出率8.7%，LD-MPS技术对致病性拷贝数变异的检测效果与arrayCGH高度一致。..此外，我们还探索增加了LD-MPS的新功能，使之能够检出arrayCGH技术无法检测的染色体易位、倒位等结构变异，精确的诊断出9例染色体结构变异。..通过本项目的研究，我们证实了LD-MPS技术是染色体缺陷诊断和人类先天缺陷的防治的一种低成本、高效率的新型检测手段，显著提高了临床遗传病诊断能力，在先天缺陷产前遗传学诊断中具有临床应用价值。