與我們普遍持有的觀念不同,，外表相似的雙胞胎，他們在遺傳上并不相同,。此項出人意料的研究,，是由美國,、瑞典及荷蘭的科學(xué)家合作完成的，研究成果刊登在了《美國人類遺傳學(xué)雜志》（American Journal of Human Genetics）上,。研究中的發(fā)現(xiàn)可能對遺傳疾病的研究及診斷方法具有重要意義,。
這是怎么發(fā)生的——雙胞胎中的一位患有帕金森病，而另一位卻沒有,？此前,，對這種現(xiàn)象的解釋，更多的是從環(huán)境方面考慮,。而現(xiàn)在,，新的研究將這個問題更為復(fù)雜化了。
“盡管形態(tài)相似的雙胞胎的基因組,，它們的絕大部分是保持一致的,，但我們的研究結(jié)果表明，還有極少量的區(qū)別,，雙胞胎的相同只不過是相對的相同,。這對于我們深入理解遺傳導(dǎo)致的疾病，是非常有幫助的,。”Jan Dumanksi介紹說,。他是此項研究的主持者之一。
“為揭示雙胞胎中僅一位患病的情況,，我們開發(fā)出了一種方法,，可以用于跟蹤導(dǎo)致這些疾病的遺傳突變。”Carl Bruder說道,。
研究者總共研究了19對雙胞胎,，發(fā)現(xiàn)他們確實有著相同的DNA，但是在個別DNA片段的拷貝數(shù)方面卻有可能存在差異,。例如,，有些片段在其中的一位雙胞胎中可能不存在，也可能拷貝數(shù)更多,。這可能可以用于解釋為何一位雙胞胎換上一種疾病,，而另一位卻正常的情況，科學(xué)家分析道,。
資料來源: Uppsala University（生命經(jīng)緯）
生物谷推薦原始出處：
The American Journal of Human Genetics,
doi:10.1016/j.ajhg.2007.12.011
Report
Phenotypically Concordant and Discordant Monozygotic Twins Display Different DNA Copy-Number-Variation Profiles
Carl E.G. Bruder1, , , Arkadiusz Piotrowski1, Antoinet A.C.J. Gijsbers2, 3, Robin Andersson4, Stephen Erickson5, Teresita Diaz de Ståhl6, Uwe Menzel6, Johanna Sandgren7, Desiree von Tell1, Andrzej Poplawski1, Michael Crowley1, Chiquito Crasto1, E. Christopher Partridge1, Hemant Tiwari5, David B. Allison1, 5, Jan Komorowski4, Gert-Jan B. van Ommen2, 3, Dorret I. Boomsma8, Nancy L. Pedersen9, Johan T. den Dunnen2, 3, Karin Wirdefeldt9 and Jan P. Dumanski1, 6
1 Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
2 Center for Human and Clinical Genetics, Leiden University Medical Center (LUMC), 2300 RC Leiden, The Netherlands
3 Center for Medical Systems Biology, 2300 RA Leiden, The Netherlands
4 Linnaeus Centre for Bioinformatics, Uppsala University, SE-75124 Uppsala, Sweden
5 Section on Statistical Genetics, Department of Biostatistics, University of Alabama at Birmingham, Ryals Public Health Building, Suite 327, Birmingham, Alabama 35294-0022, USA
6 Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden
7 Department of Surgical Sciences, Uppsala Academic Hospital, Uppsala University, SE-751 85 Uppsala, Sweden
8 Department of Biological Psychology, VU University, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands
9 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
Corresponding author
Abstract
The exploration of copy-number variation (CNV), notably of somatic cells, is an understudied aspect of genome biology. Any differences in the genetic makeup between twins derived from the same zygote represent an irrefutable example of somatic mosaicism. We studied 19 pairs of monozygotic twins with either concordant or discordant phenotype by using two platforms for genome-wide CNV analyses and showed that CNVs exist within pairs in both groups. These findings have an impact on our views of genotypic and phenotypic diversity in monozygotic twins and suggest that CNV analysis in phenotypically discordant monozygotic twins may provide a powerful tool for identifying disease-predisposition loci. Our results also imply that caution should be exercised when interpreting disease causality of de novo CNVs found in patients based on analysis of a single tissue in routine disease-related DNA diagnostics.
