脂肪酸去饱和酶基因多态性对儿童脂肪酸构成和认知记忆的影响

目的探讨脂肪酸去饱和酶（FADS）多态性对学龄儿童红细胞膜多不饱和脂肪酸(PUFAs)构成和认知记忆的影响。方法对参与补充DHA随机对照试验的8～12岁的南雄市坪田镇小学生进行基线问卷调查收集一般情况、膳食资料、体格测量并采集空腹血。采用数字广度测试和威斯康星卡片分类测试评估认知记忆功能。测定红细胞膜脂肪酸构成，提取血凝块DNA进行FADS4个位点的多态性分析。结果共调查106名三至五年级在校小学生，男生62人，女生44人，平均年龄为（9.17±1.03）岁。不同红细胞膜DHA的含量构成的调查对象认知记忆功能差异无统计学意义（均P＞0.05）。FADS的4个位点相互间符合H-W平衡（0.409～0.970）。FADS rs174561基因型不同C18∶2、C18∶3（n-6）、C20∶5、总n-3、AA/LA、EPA/ALA的比例差异有统计学意义（P＜0.01或P＜0.05）。混合线性模型分析结果发现，完成分类数、概念化水平数、概念化水平mm+Mm基因型者高于MM基因型者（均P＜0.05），mm+Mm基因型者总错误数和总错误率低于MM基因型者（均P＜0.05）。结论FADS多态性可影响学龄儿童体内PUFAs构成和认知记忆功能。

Effect of FADS single nucleotide polymorphisms on fatty acids compositionand cognitive function of children

ObjectiveTo explore the effect of fatty acid desaturase (FADS) single nucleotide polymorphisms (SNPs) on erythrocyte membrane polyunsaturated fatty acids (PUFAs) composition and cognitive memory of school-age children. MethodsPrimary school students aged 8-12 years were selected from Pingtian Town, Nanxiong City to participate in the docosahexaenoic acid (DHA) supplementation randomized controlled trial. Basic information, dietary data, anthropometric measurements and fasting blood samples were collected. Cognitive function was assessed using digital span test and Wisconsin card sorting test. Erythrocyte membrane fatty acids composition was determined by gas chromatography. Genome DNA was extracted from blood clots and used to identify the genotypes of 4 FADS tag SNPs.ResultsA total of 106 school students from grade three to grade five were investigated, including 62 males and 44 females, with an average age of (9.17 ± 1.03) years. There was no significant difference in the cognitive memory function of DHA in different erythrocyte membrane (all P＞0.05). The four sites of FADS were in accordance with H-W equilibrium (0.409-0.970). The differences of FADS rs174561 genotypes in different C18∶2, C18∶3(n-6), C20∶5, total n-3, AA/LA, EPA/ALA were statistically significant (P < 0.01 or P < 0.05). The mixed linear model analysis showed that the scores of number of completed categories and conceptual level ,conceptual level for mm+Mm genotype were higher than those for MM genotype (all P＜0.05). The total number of errors and total error rate of mm+Mm genotype were lower than those of MM (all P＜0.05). ConclusionFADS SNPs can influence PUFAs status and cognitive function in school-age children.