根據(jù)星期二發(fā)表于2007 年3月20 日The American Journal of Human Genetics電子版中的文章,，研究人員辨認(rèn)出一個(gè)新的基因突變，會(huì)導(dǎo)致與X染色體有關(guān)的智力缺陷,，目前還沒有分子技術(shù)可診斷這種智力缺陷,。
英國(guó)劍橋大學(xué)醫(yī)學(xué)院的研究人員F. Lucy Raymond 及英國(guó)Wellcome Trust Sanger研究機(jī)構(gòu)的Patrick S. Tarpey,，在這篇文章中描述他們?cè)诎l(fā)育嚴(yán)重遲緩的兒童身上，發(fā)現(xiàn)ZDHHC9基因完全失去功能,。
ZDHHC9 是一個(gè)新發(fā)現(xiàn)的基因,。之前研究人員還未預(yù)測(cè)到這個(gè)基因與智力缺陷有關(guān)。ZDHHC9之所以被發(fā)現(xiàn),，只是因?yàn)檠芯咳藛T系統(tǒng)性地觀察X 染色體上的所有基因,。
研究人員透過這項(xiàng)大型的國(guó)際合作，從至少有二個(gè)男孩發(fā)生智力缺陷的250 個(gè)家庭中收集基因樣品,，以辨認(rèn)導(dǎo)致X染色體相關(guān)之智力缺陷的新基因,。與X染色體有關(guān)的智力缺陷是相當(dāng)嚴(yán)重的。某些患者需要全天候照顧,，而且無語言能力,。這種疾病通常只發(fā)生于男性，目前為止只有一些相關(guān)基因被辨認(rèn)出,。
(資料來源 : Bio.com)
部分英文原文：
Am. J. Hum. Genet., 80:000, 2007
0002-9297/2007/8005-00XX$15.00
© 2007 by The American Society of Human Genetics. All rights reserved.
Report
Mutations in ZDHHC9, Which Encodes a Palmitoyltransferase of NRAS and HRAS, Cause X-Linked Mental Retardation Associated with a Marfanoid Habitus
F. Lucy Raymond,* Patrick S. Tarpey,* Sarah Edkins, Calli Tofts, Sarah O'Meara, Jon Teague, Adam Butler, Claire Stevens, Syd Barthorpe, Gemma Buck, Jennifer Cole, Ed Dicks, Kristian Gray, Kelly Halliday, Katy Hills, Jonathon Hinton, David Jones, Andrew Menzies, Janet Perry, Keiran Raine, Rebecca Shepherd, Alexandra Small, Jennifer Varian, Sara Widaa, Uma Mallya, Jenny Moon, Ying Luo, Marie Shaw, Jackie Boyle, Bronwyn Kerr, Gillian Turner, Oliver Quarrell, Trevor Cole, Douglas F. Easton, Richard Wooster, Martin Bobrow, Charles E. Schwartz, Jozef Gecz, Michael R. Stratton, and P. Andrew Futreal
From the Cambridge Institute of Medical Research, University of Cambridge (F.L.R.; U.M.; J.M.; Y.L.; M.B.), and Genetic Epidemiology Unit, Cancer Research UK (D.F.E.), Cambridge, United Kingdom; Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton, United Kingdom (P.S.T.; S.E.; C.T.; S.O.; J.T.; A.B.; C.S.; S.B.; G.B.; J.C.; E.D.; K.G.; K. Halliday; K. Hills; J.H.; D.J.; A.M.; J.P.; K.R.; R.S.; A.S.; J.V.; S.W.; M.S.; R.W.; M.R.S.; P.A.F.); Regional Genetics Service, St Mary's Hospital, Manchester, United Kingdom (B.K.); Genetics of Learning Disability (GOLD) Service, University of Newcastle, Newcastle, Australia (J.B.; G.T.); Clinical Genetics, Sheffield Children's Hospital, Sheffield, United Kingdom (O.Q.); Clinical Genetics, Birmingham Women's Hospital, Birmingham, United Kingdom (T.C.); JC Self Research Institute of Human Genetics, Greenwood Genetic Center, Greenwood, SC (C.E.S.); and Department of Genetic Medicine, Women's and Children's Hospital, and Departments of Paediatrics and Molecular Biosciences, University of Adelaide (M.S.; J.G.), Adelaide, Australia
Received January 11, 2007; accepted for publication February 7, 2007; electronically published March 20, 2007.
We have identified one frameshift mutation, one splice-site mutation, and two missense mutations in highly conserved residues in ZDHHC9 at Xq26.1 in 4 of 250 families with X-linked mental retardation (XLMR). In three of the families, the mental retardation phenotype is associated with a Marfanoid habitus, although none of the affected individuals meets the Ghent criteria for Marfan syndrome. ZDHHC9 is a palmitoyltransferase that catalyzes the posttranslational modification of NRAS and HRAS. The degree of palmitoylation determines the temporal and spatial location of these proteins in the plasma membrane and Golgi complex. The finding of mutations in ZDHHC9 suggests that alterations in the concentrations and cellular distribution of target proteins are sufficient to cause disease. This is the first XLMR gene to be reported that encodes a posttranslational modification enzyme, palmitoyltransferase. Furthermore, now that the first palmitoyltransferase that causes mental retardation has been identified, defects in other palmitoylation transferases become good candidates for causing other mental retardation syndromes.
