英國、加拿大等國最新研究顯示，一種罕見的能夠引起早期癡呆的大腦失常，是高度遺傳的。這項(xiàng)研究結(jié)果發(fā)布在11月3日的Neurology上,。
這種大腦失常，叫額顳葉型失智癥（frontotemporal dementia）,，就是以前的皮克?。≒ick's disease），會(huì)引起大腦的部分破壞,，導(dǎo)致癡呆,，包括語言困難或行為和性格的變化。這種疾病通常發(fā)病年齡在65歲以下,。
了解你的家庭健康史可能是一種預(yù)測該疾病發(fā)病風(fēng)險(xiǎn)的方法,，研究人員Jonathan Rohrer介紹說。
研究人員采集了225位參與者的血樣,，進(jìn)行額顳葉型失智癥的分析,。這些人還會(huì)被問及該病的家族史，并給出得分（1到4分）,。1分代表該患者至少有3個(gè)親戚患有該疾病并且是常染色體顯性遺傳,，也就是說受到影響的人有一個(gè)變異的基因和一個(gè)正常的基因，個(gè)體有50%的幾率會(huì)將變異的基因傳遞到下一代中,，導(dǎo)致后代遭受該疾病影響,。4分則代表該患者沒有額顳葉型失智癥的家族史。
這項(xiàng)研究表明,，將近42%的參與者的得分在1-3.5之間,，也就是說他們中或多或少有一些額顳葉型失智癥的家族史。只有10%有常染色體基因史,。此外研究人員進(jìn)行了5個(gè)候選變異基因的DNA檢測，發(fā)現(xiàn)了2個(gè)突變基因,。
許多人仍然有著一個(gè)強(qiáng)大的額顳葉型失智癥家族史,，即使沒有發(fā)現(xiàn)任何已知的基因突變,，這表明還存在著導(dǎo)致額顳葉型失智癥的未知基因。研究人員表示,，新基因及其變異的發(fā)現(xiàn)將有助于打開治療和預(yù)防癡呆的大門,。（生物谷Bioon.com）
生物谷推薦原始出處：
NEUROLOGY 2009;73:1451-1456
The heritability and genetics of frontotemporal lobar degeneration
J. D. Rohrer, MRCP, R. Guerreiro, MS, J. Vandrovcova, PhD, J. Uphill, BSc, D. Reiman, J. Beck, BSc, A. M. Isaacs, DPhil, A. Authier, MSc, R. Ferrari, BSc, N. C. Fox, MD, FRCP, I.R.A. Mackenzie, PhD, J. D. Warren, PhD, FRACP, R. de Silva, DPhil, J. Holton, PhD, T. Revesz, MD, J. Hardy, PhD, S. Mead, PhD, MRCP and M. N. Rossor, MD, FRCP
From the Dementia Research Centre (J.D.R., N.C.F., J.D.W., M.N.R.) and MRC Prion Unit (J.U., D.R., J.B., A.M.I., A.A., S.M.), Department of Neurodegenerative Disease, Reta Lila Weston Institute (R.F., J.H.), and Queen Square Brain Bank (J.V., R.d.S., J.H., T.R.), Department of Molecular Neuroscience, UCL Institute of Neurology, University College London, Queen Square, London, UK; Texas Tech University (R.F.), Health Sciences Center, Department of Internal Medicine, Lubbock, TX; Laboratory of Neurogenetics (R.G.), National Institute of Aging, National Institutes of Health, Bethesda, MD; Center for Neuroscience and Cell Biology (R.G.), University of Coimbra, Coimbra, Portugal; and Department of Pathology and Laboratory Medicine (I.R.A.M.), Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada.
Background: Frontotemporal lobar degeneration (FTLD) is a genetically and pathologically heterogeneous neurodegenerative disorder.
Methods: We collected blood samples from a cohort of 225 patients with a diagnosis within the FTLD spectrum and examined the heritability of FTLD by giving each patient a family history score, from 1 (a clear autosomal dominant history of FTLD) through to 4 (no family history of dementia). We also looked for mutations in each of the 5 disease-causing genes (MAPT, GRN, VCP, CHMP2B, and TARDP) and the FUS gene, known to cause motor neuron disease.
Results: A total of 41.8% of patients had some family history (score of 1, 2, 3, or 3.5), although only 10.2% had a clear autosomal dominant history (score of 1). Heritability varied across the different clinical subtypes of FTLD with the behavioral variant being the most heritable and frontotemporal dementia–motor neuron disease and the language syndromes (particularly semantic dementia) the least heritable. Mutations were found in MAPT (8.9% of the cohort) and GRN (8.4%) but not in any of the other genes. Of the remaining patients without mutations but with a strong family history, 7 had pathologic confirmation, falling into 2 groups: type 3 FTLD-TDP without GRN mutations (6) and FTLD-UPS (1).
Conclusion: These findings show that frontotemporal lobar degeneration (FTLD) is a highly heritable disorder but heritability varies between the different syndromes. Furthermore, while MAPT and GRN mutations account for a substantial proportion of familial cases, there are other genes yet to be discovered, particularly in patients with type 3 FTLD-TDP without a GRN mutation.
