生物谷導讀：多動癥是最常見的兒童精神失調(diào)疾病之一,。約3%-5%的兒童受此困擾,。近日研究者發(fā)現(xiàn)導致此疾病的原因在于DNA的片段缺失或片段復制異常,。為治療方案的確定提供了新基礎。
英國科研人員經(jīng)研究發(fā)現(xiàn),，患有多動癥的兒童,，其遺傳物質(zhì)脫氧核糖核酸（DNA）的某些片段缺失或異常復制。這是研究人員首次找到兒童多動癥與遺傳因素有關的直接證據(jù),。
英國加的夫大學的安妮塔·塔帕爾領導的研究小組在新一期《柳葉刀》雜志上報告說,，他們選取了1400多名兒童，進行基因組圖譜掃描,。結果發(fā)現(xiàn),，患有多動癥的兒童，其DNA明顯比正常兒童更容易出現(xiàn)“拷貝數(shù)變異”,，即片段缺失或片段復制異常,。
塔帕爾說，他們的研究結果直接表明,，多動癥是一種遺傳失調(diào)導致的疾病,，從而導致多動癥患兒的大腦與其他兒童的大腦發(fā)育存在差異。
多動癥是“注意缺陷障礙”的俗稱,，是最常見的兒童精神失調(diào)疾病之一,。這是一種兒童輕微腦功能失調(diào)疾病，表現(xiàn)為注意力不能集中,，異常好動,，自我控制能力差，但沒有明顯的智力障礙,。據(jù)估計，約有3%至5%的兒童會受到多動癥的困擾，其中男孩比例大于女孩,。
在此之前,，多動癥的病因在醫(yī)學上一直沒有得到確認。有研究者認為,，多動癥的病因可能與父母教養(yǎng)習慣有關,，或者與兒童通過飲食攝入糖分過多等不良習慣有關。該病迄今尚無有效的治愈療法,，通常只能靠藥物和行為矯正來控制癥狀,。
塔帕爾等人認為，在他們的研究成果基礎上,，將來有望研制出針對多動癥的新藥物,，進而開發(fā)出更加有效的治療方案。（生物谷Bioon.com）
生物谷推薦英文摘要：
The Lancet doi:10.1016/S0140-6736(10)61109-9
Rare chromosomal deletions and duplications in attention-deficit hyperactivity disorder: a genome-wide analysis
Dr Nigel M Williams PhD a, Irina Zaharieva BSc a, Andrew Martin BSc a, Kate Langley PhD a, Kiran Mantripragada PhD a, Ragnheidur Fossdal PhD b, Hreinn Stefansson PhD b, Kari Stefansson MD b, Pall Magnusson MD c, Olafur O Gudmundsson MD c, Omar Gustafsson PhD bd, Prof Peter Holmans PhD a, Prof Michael J Owen MD a, Prof Michael O'Donovan MD a, Prof Anita Thapar MD a
Background
Large, rare chromosomal deletions and duplications known as copy number variants (CNVs) have been implicated in neurodevelopmental disorders similar to attention-deficit hyperactivity disorder (ADHD). We aimed to establish whether burden of CNVs was increased in ADHD, and to investigate whether identified CNVs were enriched for loci previously identified in autism and schizophrenia.
Methods
We undertook a genome-wide analysis of CNVs in 410 children with ADHD and 1156 unrelated ethnically matched controls from the 1958 British Birth Cohort. Children of white UK origin, aged 5—17 years, who met diagnostic criteria for ADHD or hyperkinetic disorder, but not schizophrenia and autism, were recruited from community child psychiatry and paediatric outpatient clinics. Single nucleotide polymorphisms (SNPs) were genotyped in the ADHD and control groups with two arrays; CNV analysis was limited to SNPs common to both arrays and included only samples with high-quality data. CNVs in the ADHD group were validated with comparative genomic hybridisation. We assessed the genome-wide burden of large (>500 kb), rare (<1% population frequency) CNVs according to the average number of CNVs per sample, with significance assessed via permutation. Locus-specific tests of association were undertaken for test regions defined for all identified CNVs and for 20 loci implicated in autism or schizophrenia. Findings were replicated in 825 Icelandic patients with ADHD and 35 243 Icelandic controls.
Findings
Data for full analyses were available for 366 children with ADHD and 1047 controls. 57 large, rare CNVs were identified in children with ADHD and 78 in controls, showing a significantly increased rate of CNVs in ADHD (0·156 vs 0·075; p=8·9×10?5). This increased rate of CNVs was particularly high in those with intellectual disability (0·424; p=2·0×10?6), although there was also a significant excess in cases with no such disability (0·125, p=0·0077). An excess of chromosome 16p13.11 duplications was noted in the ADHD group (p=0·0008 after correction for multiple testing), a finding that was replicated in the Icelandic sample (p=0·031). CNVs identified in our ADHD cohort were significantly enriched for loci previously reported in both autism (p=0·0095) and schizophrenia (p=0·010).
Interpretation
Our findings provide genetic evidence of an increased rate of large CNVs in individuals with ADHD and suggest that ADHD is not purely a social construct.
Funding
Action Research; Baily Thomas Charitable Trust; Wellcome Trust; UK Medical Research Council; European Union.
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