生物谷报道:德国科学家发现了导致“失读症”的基因DCDC2,此项成果有望为该病症的治疗开辟道路。
“失读症”患者在文字阅读和书写方面有明显困难。科学家早就认识到该病可能与基因有关,如今这种基因已被德国国家遗传研究所的科学家找到。
科学家分析了137名“失读症”儿童和他们父母的基因组成,发现一种被称为DCDC2的基因会影响胎儿脑部发育时神经细胞的运动。
科学家表示,这种基因可能阻碍人脑发育,从而导致阅读障碍。身上存在这种基因的人患“失读症”的几率比其他人高5倍以上。
数据显示,在德国有大约500万人患有“失读症”,其中有5%至12%的“失读症”患者是儿童。
有关失读症的研究,近一年来有重大突破,自从去年底华人科学家梦海英在PNAS上发现DCDC2可能与读写有关的基因以来,2006年相关科学家进一步证实与失读症相关。
系列研究相关文章如下:
McGrath LM, Smith SD, Pennington BF.Breakthroughs in the search for dyslexia candidate genes.
Trends Mol Med. 2006 Jun 15; [Epub ahead of print]
Fisher SE, Francks C.Genes, cognition and dyslexia: learning to read the genome.
Trends Cogn Sci. 2006 Jun;10(6):250-7. Epub 2006 May 3.
Schumacher J, Anthoni H, Dahdouh F, Konig IR, Hillmer AM, Kluck N, Manthey M, Plume E, Warnke A, Remschmidt H, Hulsmann J, Cichon S, Lindgren CM, Propping P, Zucchelli M, Ziegler A, Peyrard-Janvid M, Schulte-Korne G, Nothen MM, Kere J.Strong genetic evidence of DCDC2 as a susceptibility gene for dyslexia.
Am J Hum Genet. 2006 Jan;78(1):52-62. Epub 2005 Nov 17.
Meng H, Smith SD, Hager K, Held M, Liu J, Olson RK, Pennington BF, DeFries JC, Gelernter J, O'Reilly-Pol T, Somlo S, Skudlarski P, Shaywitz SE, Shaywitz BA, Marchione K, Wang Y, Paramasivam M, LoTurco JJ, Page GP, Gruen JR.DCDC2 is associated with reading disability and modulates neuronal development in the brain.
Proc Natl Acad Sci U S A. 2005 Nov 22;102(47):17053-8. Epub 2005 Nov 8. Erratum in: Proc Natl Acad Sci U S A. 2005 Dec 20;102(51):18763
Cope N, Harold D, Hill G, Moskvina V, Stevenson J, Holmans P, Owen MJ, O'Donovan MC, Williams J. Strong evidence that KIAA0319 on chromosome 6p is a susceptibility gene for developmental dyslexia.
Am J Hum Genet. 2005 Apr;76(4):581-91. Epub 2005 Feb 16. Erratum in: Am J Hum Genet. 2005 Nov;77(5):898.
有关DCDC2基因的信息见: http://www.genecards.org/cgi-bin/carddisp.pl?gene=DCDC2
Pediatric researchers at Yale School of Medicine have identified a gene on human chromosome 6 called DCDC2, which is linked to dyslexia, a reading disability affecting millions of children and adults.
The researchers also found that a genetic alteration in DCDC2 leads to a disruption in the formation of brain circuits that make it possible to read. This genetic alteration is transmitted within families.
"These promising results now have the potential to lead to improved diagnostic methods to identify dyslexia and deepens understanding of how the reading process works on a molecular level," said lead author Jeffrey R. Gruen, M.D., associate professor in the Pediatrics Department at Yale School of Medicine.
Gruen and co-authors used a statistical approach to study and compare specific DNA markers in 153 dyslexic families. "We now have strong statistical evidence that a large number of dyslexic cases--perhaps as many as 20 percent--are due to the DCDC2 gene," said Gruen. "The genetic alteration on this chromosome is a large deletion of a regulatory region. The gene itself is expressed in reading centers of the brain where it modulates migration of neurons. This very architecture of the brain circuitry is necessary for normal reading."
To facilitate reading, brain circuits need to communicate with each other. In reading disabilities, these circuits are disrupted. In people with dyslexia, compensatory brain circuits are inefficient and they have a hard time learning to read.
Locating this gene provided researchers with part of the reason why dyslexia occurs. Gruen said discovery of the gene and its function will lead to early and more accurate diagnoses and more effective educational programs to address the unique needs and special talents of people with dyslexia.
"We can't continue the cookie cutter, one-size-fits-all schooling anymore," said Gruen. "People with dyslexia are not less intelligent than others, they just learn in different ways. Tailoring programs to fit the needs of these children will enhance their success in school and be more cost effective."
Other authors on the study were Shelley D. Smith, Karl Hager, Matthew Held, Jonathan Liu, Richard K. Olson, Bruce F. Pennington, John C. DeFries, Joel Gelernter, Thomas O'Reilly-Pol, Stefan Somlo, Pawel Skudlarski, Sally E. Shaywitz, Bennett A. Shaywitz, Karen Marchione, Yu Wang, Murugan Parmasivam, Joseph J. LoTurco and Grier P. Page.