在全世界最大規(guī)模的腦研究中,，由來(lái)自全世界100個(gè)研究機(jī)構(gòu)的200多個(gè)研究人員組成的研究小組,，共同繪制出一些人類基因，這些基因有的促進(jìn)大腦抵抗各種精神疾病與阿爾茨海默病,，有的破壞大腦對(duì)那些疾病的抵抗,。相關(guān)研究結(jié)果發(fā)表在4月15日在線版Nature Genetics上，揭示了用來(lái)解釋大腦大小與智力個(gè)體差異的新基因,。
研究人員不僅探討增加單一疾病遺傳風(fēng)險(xiǎn)的基因,，也對(duì)導(dǎo)致組織萎縮和大腦尺寸減小的因素進(jìn)行了研究，也就是遺傳性疾病生物學(xué)標(biāo)志,，這里的遺傳性疾病主要是精神分裂癥,、雙相性精神障礙、抑郁癥,、阿爾茨海默癥和癡呆,。同時(shí),，還特別地尋找出使健康人腦組織超常耗竭的基因變異。此項(xiàng)目規(guī)模龐大,，足以使研究小組發(fā)掘某些人的新遺傳變異,，這些人不但有更大體積的大腦，而且學(xué)習(xí)記憶關(guān)鍵域存在差異,。結(jié)果發(fā)現(xiàn),，有一種統(tǒng)一聯(lián)系，該聯(lián)系存在遺傳密碼細(xì)微變化與記憶中心縮減之間,，即：HMGA2基因的一個(gè)變異既影響大腦尺寸,，也影響智力。若某人HMGA2基因上T堿基被C堿基替代,，他就會(huì)有一個(gè)尺寸較大的大腦,，在標(biāo)準(zhǔn)IQ測(cè)試中得分也高得多。
此研究提供了相當(dāng)明確的證據(jù),，來(lái)證明大腦功能,、智力與遺傳的關(guān)聯(lián)。因?yàn)?，像阿爾茨海默癥,、孤獨(dú)癥及精神分裂癥這樣的疾病能瓦解大腦“電路系統(tǒng)”，所以,，下一步將要搜尋出那些影響大腦連線的基因,。（生物谷bioon.com）
doi:10.1038/ng.2250
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Identification of common variants associated with human hippocampal and intracranial volumes
Jason L Stein, Sarah E Medland, Alejandro Arias Vasquez, Derrek P Hibar, Rudy E Senstad,Anderson M Winkler, Roberto Toro, Katja Appel, Richard Bartecek, ?rjan Bergmann, Manon Bernard, Andrew A Brown, Dara M Cannon, M Mallar Chakravarty, Andrea Christoforou, Martin Domin, Oliver Grimm, Marisa Hollinshead, Avram J Holmes, Georg Homuth, Jouke-Jan Hottenga,Camilla Langan, Lorna M Lopez, Narelle K Hansell, Kristy S Hwang et al.
Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease1, 2 and is reduced in schizophrenia3, major depression4 and mesial temporal lobe epilepsy5. Whereas many brain imaging phenotypes are highly heritable6, 7, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10-16) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10-12). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10-7).
