创伤后应激障碍(PTSD)患者会在悲惨事件后表现出极端焦虑、消沉及恶梦等。对PTSD的易感性因人而异,有些人在较小的创伤后就会发生这种症状,而另外一些人在经历战争、飓风和各种形式的身体虐待后情绪仍然不会崩溃。美国科学家近日研究发现,儿童期遭受虐待的人日后生活中是否会发生PTSD,可能主要由某种与应激有关的基因变异来决定。相关论文发表在3月19日的《美国医学协会期刊》(JAMA)上。
之前的研究表明,儿童期遭受虐待的人更易患PTSD,并且研究人员估计,多达40%的这种易感性是可遗传的,但是起作用的基因一直没有弄清。其中一个可能的是基因FKBP5,它帮助调节应激激素和其受体之间的绑定。
在最新的研究中,美国埃默里大学的研究人员收集了762个人的数据,他们大部分都来自穷困的黑人生活区,并在为期2年的时间里以非精神病的原因去诊所就诊。通过采访和问卷,参与者报告了儿童期虐待及其它一些类型的后期生活创伤。参与者还被要求留下唾液样本以进行DNA检测。
有30%的参与者报告曾经历过儿童期身体或性虐待,这些人后期遭受创伤时表现出PTSD症状的数量是那些未曾报告遭受虐待的人的两倍。并且,FKBP5两个特殊的突变在这些曾遭受虐待的人身上也更为常见。这些突变自身并不会预报PTSD,表明是某种基因与早期创伤的结合导致了PTSD的易感性。研究人员总结说,某些突变使得儿童的脑细胞在一生当中都对应激激素更为敏感。
新西兰奥塔哥大学(University of Otago)的基因-环境交感专家Richie Poulton认为,这一发现是复杂的,并且只是初步的研究,但从生物学上看来是有道理的。美国国立心理健康研究所的精神病学家Daniel Weinberger则表示,这是一篇重要的文章,“它表明,最好是在其它危险因素的背景下来研究与复杂精神病状况相关的基因。我认为这是将来的发展趋势。”(科学网 梅进/编译)
生物谷推荐原始出处:
(JAMA),299(11):1291-1305,Elisabeth B. Binder,Kerry J. Ressler
Association of FKBP5 Polymorphisms and Childhood Abuse With Risk of Posttraumatic Stress Disorder Symptoms in Adults
Elisabeth B. Binder, MD, PhD; Rebekah G. Bradley, PhD; Wei Liu, PhD; Michael P. Epstein, PhD; Todd C. Deveau, BS; Kristina B. Mercer, MPH; Yilang Tang, MD, PhD; Charles F. Gillespie, MD, PhD; Christine M. Heim, PhD; Charles B. Nemeroff, MD, PhD; Ann C. Schwartz, MD; Joseph F. Cubells, MD, PhD; Kerry J. Ressler, MD, PhD
JAMA. 2008;299(11):1291-1305.
Context In addition to trauma exposure, other factors contribute to risk for development of posttraumatic stress disorder (PTSD) in adulthood. Both genetic and environmental factors are contributory, with child abuse providing significant risk liability.
Objective To increase understanding of genetic and environmental risk factors as well as their interaction in the development of PTSD by gene x environment interactions of child abuse, level of non–child abuse trauma exposure, and genetic polymorphisms at the stress-related gene FKBP5.
Design, Setting, and Participants A cross-sectional study examining genetic and psychological risk factors in 900 nonpsychiatric clinic patients (762 included for all genotype studies) with significant levels of childhood abuse as well as non–child abuse trauma using a verbally presented survey combined with single-nucleotide polymorphism (SNP) genotyping. Participants were primarily urban, low-income, black (>95%) men and women seeking care in the general medical care and obstetrics-gynecology clinics of an urban public hospital in Atlanta, Georgia, between 2005 and 2007.
Main Outcome Measures Severity of adult PTSD symptomatology, measured with the modified PTSD Symptom Scale, non–child abuse (primarily adult) trauma exposure