同卵（或更準(zhǔn)確地說“單合子”）雙胞胎被廣泛用來研究遺傳和環(huán)境對人們疾病的貢獻(xiàn),。
新一期英國《自然》雜志報告說,，一項雙胞胎對比研究發(fā)現(xiàn),，多發(fā)性硬化癥并不完全受基因因素控制,。
此前的研究曾認(rèn)為,，多發(fā)性硬化癥是一種遺傳性疾病,，是否患病,，完全由人體內(nèi)的基因組決定。
為了驗證這項結(jié)論,，美國加利福尼亞大學(xué)等機(jī)構(gòu)研究人員選擇一對女性雙胞胎進(jìn)行研究,。雙胞胎其中一人患有多發(fā)性硬化癥，另一人完全健康,。研究人員對這對姐妹進(jìn)行了完整基因組測序,。對比結(jié)果發(fā)現(xiàn)，兩人基因組沒有重大差異,。
研究人員認(rèn)為,，這個結(jié)果表明，多發(fā)性硬化癥并不完全受基因控制,。從基因角度來說,，這對雙胞胎出生時的患病風(fēng)險是完全相同的，但后來只有一人發(fā)病,，另一人保持健康,。這說明除了基因因素以外，多發(fā)性硬化癥發(fā)病肯定還受到外界環(huán)境因素等的影響,。
多發(fā)性硬化癥是一種神經(jīng)系統(tǒng)疾病,，患者自身免疫細(xì)胞會錯誤攻擊神經(jīng)元髓鞘，造成患者出現(xiàn)視覺障礙,、肌肉無力等癥狀,。(生物谷Bioon.com)
更多閱讀
Nature Medicine：β干擾素治療多發(fā)性硬化癥與免疫細(xì)胞類型相關(guān)
Nature Immunology：非編碼小RNA在多發(fā)性硬化癥發(fā)生過程中作用機(jī)制
Genome Research：同卵雙胞胎表觀遺傳學(xué)特征不同
生物谷推薦原文出處：
Nature doi:10.1038/nature08990
Genome, epigenome and RNA sequences of monozygotic twins discordant for multiple sclerosis
Sergio E. Baranzini,Joann Mudge,Jennifer C. van Velkinburgh,Pouya Khankhanian,Irina Khrebtukova,Neil A. Miller,Lu Zhang,Andrew D. Farmer,Callum J. Bell,Ryan W. Kim,Gregory D. May,Jimmy E. Woodward,Stacy J. Caillier,Joseph P. McElroy,Refujia Gomez,Marcelo J. Pando,Leonda E. Clendenen,Elena E. Ganusova,Faye D. Schilkey,Thiruvarangan Ramaraj,Omar A. Khan,Jim J. Huntley,Shujun Luo,Pui-yan Kwok,Thomas D. Wu,Gary P. Schroth,Jorge R. Oksenberg,Stephen L. Hauser
& Stephen F. Kingsmore et al.
Monozygotic or ‘identical’ twins have been widely studied to dissect the relative contributions of genetics and environment in human diseases. In multiple sclerosis (MS), an autoimmune demyelinating disease and common cause of neurodegeneration and disability in young adults, disease discordance in monozygotic twins has been interpreted to indicate environmental importance in its pathogenesis1, 2, 3, 4, 5, 6, 7, 8. However, genetic and epigenetic differences between monozygotic twins have been described, challenging the accepted experimental model in disambiguating the effects of nature and nurture9, 10, 11, 12. Here we report the genome sequences of one MS-discordant monozygotic twin pair, and messenger RNA transcriptome and epigenome sequences of CD4+ lymphocytes from three MS-discordant, monozygotic twin pairs. No reproducible differences were detected between co-twins among ~3.6 million single nucleotide polymorphisms (SNPs) or ~0.2 million insertion-deletion polymorphisms. Nor were any reproducible differences observed between siblings of the three twin pairs in HLA haplotypes, confirmed MS-susceptibility SNPs, copy number variations, mRNA and genomic SNP and insertion-deletion genotypes, or the expression of ~19,000 genes in CD4+ T cells. Only 2 to 176 differences in the methylation of ~2?million CpG dinucleotides were detected between siblings of the three twin pairs, in contrast to ~800 methylation differences between T cells of unrelated individuals and several thousand differences between tissues or between normal and cancerous tissues. In the first systematic effort to estimate sequence variation among monozygotic co-twins, we did not find evidence for genetic, epigenetic or transcriptome differences that explained disease discordance. These are the first, to our knowledge, female, twin and autoimmune disease individual genome sequences reported.
