Suresh Raviraj V, Lingaiah Kusuma, Veerappa Avinash M, Ramachandra Nallur B
Department of Studies in Genetics & Genomics, University of Mysore, Mysuru, India.
Indian J Med Res. 2017 Jan;145(1):39-50. doi: 10.4103/ijmr.IJMR_965_14.
BACKGROUND & OBJECTIVES: Aneuploids are the most common chromosomal abnormality in liveborns and are usually the result of non-disjunction (NDJ) in meiosis. Copy number variations (CNVs) are large structural variations affecting the human genome. CNVs influence critical genes involved in causing NDJ by altering their copy number which affects the clinical outcome. In this study influence of CNVs on critical meiotic recombination was examined using new computational technologies to assess their role in causing aneuploidy.
This investigation was based on the analysis of 12 random normal populations consisting of 1714 individuals for aneuploid causing genes under CNV effect. To examine the effect of CNVs on genes causing aneuploidy, meiotic recombination genes were analyzed using EnrichR, WebGestalt and Ingenuity Pathway Analysis (IPA).
Forty three NDJ genes were found under CNV burden; IPA (Ingenuity Pathway Analysis) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis of CNV in meiotic recombination genes revealed a significant role of breast cancer gene 1, amyloid protein precursor, mitogen-activated protein kinase and nerve growth factor as key molecular players involved in causing aneuploidy. Interaction between these genes with other CNV-overlapping genes involved in cell cycle, recombination and meiosis might lead to increased incidences of aneuploidy.
INTERPRETATION & CONCLUSIONS: The findings of this study implied that the effect of CNVs on normal genome contributed in amplifying the occurrences of chromosomal aneuploidies. The normal individuals consisting of variations in the susceptible genes causing aneuploids in the population remain undetected until the disorder genes express in the succeeding generations.
非整倍体是活产儿中最常见的染色体异常,通常是减数分裂过程中不分离(NDJ)的结果。拷贝数变异(CNV)是影响人类基因组的大型结构变异。CNV通过改变关键基因的拷贝数来影响导致NDJ的关键基因,进而影响临床结局。在本研究中,使用新的计算技术检测了CNV对关键减数分裂重组的影响,以评估其在导致非整倍体中的作用。
本研究基于对12个随机正常人群(共1714人)进行分析,以研究受CNV影响的非整倍体致病基因。为检测CNV对非整倍体致病基因的影响,使用EnrichR、WebGestalt和 Ingenuity Pathway Analysis(IPA)对减数分裂重组基因进行分析。
发现43个NDJ基因受CNV影响;对减数分裂重组基因中的CNV进行IPA(Ingenuity Pathway Analysis)和KEGG(京都基因与基因组百科全书)通路分析,结果显示乳腺癌基因1、淀粉样蛋白前体、丝裂原活化蛋白激酶和神经生长因子作为导致非整倍体的关键分子发挥了重要作用。这些基因与其他参与细胞周期、重组和减数分裂的CNV重叠基因之间的相互作用可能导致非整倍体发生率增加。
本研究结果表明,CNV对正常基因组的影响促使染色体非整倍体发生率增加。在人群中,由导致非整倍体产生的易感基因变异组成的正常个体,直到致病基因在后代中表达才会被发现。