Two large scientific studies have found seven new genetic variants that make people put on weight, to add to two genes that were already linked to obesity in the general population.

    Both research teams – one led by deCode Genetics, an Icelandic biotechnology company, and the other an international academic consortium – published their findings on the 14 Dec in the journal Nature Genetics.

    The discoveries will be important for the global fight against obesity, one of the greatest public health problems of the 21st century.

    The most significant feature of the newly identified genes is that almost all of them are active in the brain, implying that they affect appetite rather than the biochemical processes of energy or fat metabolism.

    “This suggests that, as we work to develop better means of combating obesity, including using these discoveries as the first step in developing new drugs, we need to focus on the regulation of appetite at least as much as on the metabolic factors of how the body uses and stores energy,” said Kari Stefansson, chief executive of deCode.

    Samples from a total of more than 100,000 people were analysed in the two “genome-wide association studies”, which used the latest DNA-reading technology to associate genetic variations with body mass index.

    Body mass index is the most commonly used measure of obesity.

    Family and twin studies have shown that genetic factors account for 40-70 per cent of population variation in body mass index.

    Yet the first gene contributing to obesity in the general population, as opposed to people with rare metabolic disorders, was not discovered until 2007.

    Each of the newly identified genetic variations has only a modest effect: someone who carries all seven would typically be 1.5kg to 2kg heavier than an average adult.

    除了已經(jīng)與普通人群肥胖癥掛鉤的兩種基因，兩項(xiàng)大型科學(xué)研究新發(fā)現(xiàn)了七種致人體重增加的基因變異。

    兩個(gè)研究小組——一個(gè)由冰島生物技術(shù)公司基因解碼(deCode Genetics)領(lǐng)導(dǎo)，另一個(gè)為國(guó)際學(xué)者聯(lián)盟——都于12月14日在《自然-遺傳學(xué)》雜志(Nature Genetics)上公布了他們的發(fā)現(xiàn)。

    這些發(fā)現(xiàn)將對(duì)全球抵御肥胖癥的戰(zhàn)斗具有重要意義。肥胖癥是21世紀(jì)最嚴(yán)重的公共健康問題之一。

    新發(fā)現(xiàn)的基因最顯著的特征是，它們幾乎全部活躍于大腦，這意味著它們影響著食欲，而非能量或脂肪新陳代謝的生化過(guò)程。

    基因解碼公司首席執(zhí)行官凱里•斯蒂芬森(Kari Stefansson)表示：“這表明，在我們努力改進(jìn)抵御肥胖癥的方法時(shí)，包括將這些發(fā)現(xiàn)作為研發(fā)新藥物的第一步，我們對(duì)調(diào)整食欲的關(guān)注度，至少要達(dá)到對(duì)人體消耗和儲(chǔ)存能量的新陳代謝因子的關(guān)注程度。”

    兩項(xiàng)“全基因組關(guān)聯(lián)研究”(genome-wide association studies)對(duì)來(lái)自10余萬(wàn)人的樣本進(jìn)行了分析，利用最新的DNA解讀技術(shù)，將基因突變與人體質(zhì)量指數(shù)(body mass index)聯(lián)系起來(lái)。

    人體質(zhì)量指數(shù)是采用最為廣泛的肥胖測(cè)量標(biāo)準(zhǔn)。

    對(duì)家庭和雙生子的研究表明，基因因素占人體質(zhì)量指數(shù)群體變異的40%至70%。

    不過(guò)，導(dǎo)致普通人群肥胖（相對(duì)于罕見的新陳代謝紊亂人群）的基因直到2007年才被首次發(fā)現(xiàn)。

    每種新發(fā)現(xiàn)的基因突變都僅產(chǎn)生微弱的影響：攜帶全部七種基因的人通常會(huì)比普通成年人重1.5至2公斤。