tailieunhanh - Báo cáo y học: "A Melanesian -thalassemia mutation suggests a novel mechanism for regulating gene expression"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: A Melanesian -thalassemia mutation suggests a novel mechanism for regulating gene expression. | Minireview A Melanesian a-thalassemia mutation suggests a novel mechanism for regulating gene expression Qiliang Li Address Division of Medical Genetics Department of Medicine University of Washington Seattle WA 98195 USA. Email li111640@ Published 24 October 2006 Genome Biology 2006 7 238 doi gb-2006-7-l0-238 The electronic version of this article is the complete one and can be found online at http 2006 7 10 238 2006 BioMed Central Ltd Abstract A Melanesian variant of the genetic disease a-thalassemia has recently been shown to be due to a single-nucleotide polymorphism located between the adult a-globin genes and their enhancers. The finding that this mutation creates a novel promoter provides support for a mechanism of gene regulation by facilitated chromatin looping. Approximately of the human genome sequence is responsible for the variation among individuals and the majority of these differences are single-nucleotide polymorphisms SNPs . Although most SNPs are stable and have no deleterious effects others are likely to contribute to individuality disease susceptibility and individual responses to therapeutic drugs. At present such functional SNPs have mostly been identified in diseases that are caused by defects in a single gene monogenic diseases although SNPs have also been linked to complex diseases such as hypertension diabetes heart disease and cancer as well as to responses to drugs. SNPs are important not only in medicine but also in basic molecular biology as they represent a natural library of variations that can be used to elucidate and validate mechanisms of gene expression in vivo. In this regard a SNP in the gene for myostatin - a transcription factor inhibiting muscle development - has recently been shown to contribute to the muscular hypertrophy typical of the Texel breed of sheep 1 . A G A transition in the 3 untranslated region of the gene for myostatin creates a target site for a microRNA which .