Schmechel Donald Everett
Department of Medicine, Duke University Medical Center, Medical Director, The Falls Neurology and Memory Center, 4355 Hickory Boulevard (US 321), Granite Falls, NC 28630, United States.
Neurotoxicology. 2007 Sep;28(5):899-914. doi: 10.1016/j.neuro.2007.05.011. Epub 2007 Jun 14.
Persons heterozygous for Z, S and rare alpha-1-antitrypsin (AAT, SERPIN1A) polymorphisms (ca. 9% of population) are often considered 'silent' carriers with increased vulnerability to environmentally modulated liver and lung disease. They may have significantly more anxiety and bipolar spectrum disorders, nutritional compromise, and white matter disease [Schmechel DE, Browndyke J, Ghio A. Strategies for the dissection of genetic-environmental interactions in neurodegenerative disorders. Neurotoxicology 2006;27:637-57]. Given association of art and mood disorders, we examined occupation and artistic vocation from this same series. One thousand five hundred and thirty-seven consecutive persons aged 16-90 years old received comprehensive work-up including testing for AAT 'phenotype' and level, nutritional factors, and inflammatory, iron and copper indices. Occupations were grouped by Bureau of Labor Standards classification and information gathered on artistic activities. Proportion of reactive airway disease, obstructive pulmonary disease, and pre-existing anxiety disorder or bipolar disorder were significantly increased in persons carrying AAT non-M polymorphisms compared to normal MM genotype (respectively, 10, 20, 21, and 33% compared to 8, 12, 11, and 9%; contingency table, pulmonary: chi2 37, p=0.0001; affective disorder: chi2=171, p=0.0001). In persons with artistic avocation (n=189) or occupation (n=57), AAT non-M polymorphisms are significantly increased (respectively, proportions of 44 and 40% compared to background rate of 9%; contingency table, avocation: chi2=172, p=0.0001; occupation: chi2=57, p=0.0007). Artistic ability and 'anxiety/bipolar spectrum' mood disorders may represent phenotypic attributes that had selective advantage during recent human evolution, an 'intensive creative energy' (ICE) behavioral phenotype. Background proportion of ICE of 7% consists of 49 of 1312 persons with AAT MM genotype (4%), and 58 of 225 persons with non-MM genotypes (26%) (contingency table, chi2=222, p=0.0001). Penetrance of ICE increases in genotypes with lower AAT levels: PiMS, 18%; PiMZ, 44%; PiSS and PiZZ, 100% (five cases). At all ages, persons with non-MM genotype had significantly higher proportion of thiamine deficiency (50% in PiMZ), reactive hypoglycemia (20% in PiMZ), and possibly fatty liver (thiamine: chi2=28, p=0.0001; hypoglycemia: chi2=92, p=0.0001). In older persons, PiMZ genotype had significantly increased proportion (46%) of brain MRI T2 white matter abnormalities (chi2=49, p=0.003). Persons with ICE and MM genotype showed increased prevalence of pulmonary disorders and same signature as S and Z carriers and homozygotes (see above). Z polymorphism was associated with delayed age of onset (average 7 years) for persons with toxic environmental or occupational exposures (log rank, p=0.0001) and more stable cognitive change in persons with neurodegenerative illness (p<0.05). At all ages, ICE phenotype and Z polymorphism were associated with altered copper homeostasis with low or absent non-ceruloplasmin bound copper (p<0.05). AAT polymorphisms which affect iron, lipid and copper metabolism may affect early events in nervous system development, function and response to environmental exposures. AAT may also be a 'switch' for copper metabolism and low 'free' copper would be theorized to provide protection for lipid oxidation and favorably affect beta-amyloid and other aggregation, but possibly alter early 'critical' period of CNS development. AAT polymorphisms may define an important and treatable subset of persons presenting with CNS disorders. This new proposed phenotype for AAT transcends classic pattern of strictly liver and lung disease, and should be considered for proper evaluation and management of patients presenting with classic AAT-related disorders, affective disorders, persons with ICE, white matter disease or multisystem disorders of memory.
Z、S和罕见的α-1-抗胰蛋白酶(AAT,丝氨酸蛋白酶抑制剂1A)基因多态性的杂合子个体(约占人群的9%)通常被视为“沉默”携带者,他们更容易受到环境因素影响而患肝脏和肺部疾病。他们可能患有明显更多的焦虑症和双相情感障碍谱系疾病、营养缺乏以及白质疾病[施梅切尔DE、布朗戴克J、吉奥A。神经退行性疾病中基因-环境相互作用的剖析策略。神经毒理学2006;27:637 - 57]。鉴于艺术与情绪障碍之间的关联,我们从同一组人群中研究了职业和艺术职业。1537名年龄在16 - 90岁的连续受试者接受了全面检查,包括检测AAT“表型”和水平、营养因素以及炎症、铁和铜指标。职业按照劳工标准局的分类进行分组,并收集有关艺术活动的信息。与正常MM基因型相比,携带AAT非M基因多态性的个体中反应性气道疾病、阻塞性肺疾病以及既往焦虑症或双相情感障碍的比例显著增加(分别为10%、20%、21%和33%,而正常MM基因型分别为8%、12%、11%和9%;列联表,肺部疾病:卡方值37,p = 0.0001;情感障碍:卡方值 = 171,p = 0.0001)。在有艺术爱好(n = 189)或从事艺术职业(n = 57)的人群中,AAT非M基因多态性显著增加(分别为44%和40%,而背景率为9%;列联表,爱好:卡方值 = 172,p = 0.0001;职业:卡方值 = 57,p = 0.0007)。艺术能力和“焦虑/双相情感障碍谱系”情绪障碍可能代表了在人类近期进化过程中具有选择优势的表型特征,即一种“强烈的创造力”(ICE)行为表型。ICE的背景比例为7%,包括1312名AAT MM基因型个体中的49名(4%)以及225名非MM基因型个体中的58名(26%)(列联表,卡方值 = 222,p = 0.0001)。ICE的外显率在AAT水平较低的基因型中增加:PiMS为18%;PiMZ为44%;PiSS和PiZZ为100%(5例)。在所有年龄段,非MM基因型个体中硫胺素缺乏的比例显著更高(PiMZ中为50%)、反应性低血糖的比例显著更高(PiMZ中为20%),可能还有脂肪肝(硫胺素:卡方值 = 28,p = 0.0001;低血糖:卡方值 = 92,p = 0.0001)。在老年人中,PiMZ基因型个体脑MRI T2白质异常的比例显著增加(46%)(卡方值 = 49,p = 0.003)。具有ICE和MM基因型的个体肺部疾病患病率增加,且与S和Z携带者及纯合子具有相同特征(见上文)。Z基因多态性与有毒环境或职业暴露个体的发病年龄延迟(平均7年)相关(对数秩检验,p = 0.0001),并且与神经退行性疾病患者更稳定的认知变化相关(p < 0.05)。在所有年龄段,ICE表型和Z基因多态性与铜稳态改变相关,非铜蓝蛋白结合铜含量低或缺乏(p < 0.05)。影响铁、脂质和铜代谢的AAT基因多态性可能影响神经系统发育、功能以及对环境暴露反应的早期事件。AAT也可能是铜代谢的一个“开关”,理论上低“游离”铜可保护脂质氧化并对β-淀粉样蛋白及其他聚集物产生有利影响,但可能会改变中枢神经系统发育的早期“关键”时期。AAT基因多态性可能定义了一个重要且可治疗的中枢神经系统疾病患者亚组。这种新提出的AAT表型超越了严格的肝脏和肺部疾病的经典模式,对于出现经典AAT相关疾病、情感障碍、ICE个体、白质疾病或记忆多系统疾病的患者,应考虑进行适当评估和管理。