title: Association between ε2/3/4, promoter polymorphism (-491A/T, -427T/C, and -219T/G) at the apolipoprotein E gene, and mental retardation in children from an iodine deficiency area, China.
abstract: BACKGROUND
  Several common single-nucleotide polymorphisms (SNPs) at apolipoprotein E (ApoE) have been linked with late onset sporadic Alzheimer's disease and declining normative cognitive ability in elder people, but we are unclear about their relationship with cognition in children.
  
  
  RESULTS
  We studied -491A/T, -427T/C, and -219G/T promoter polymorphisms and ε2/ε3/ε4 at ApoE among children with mental retardation (MR, n = 130), borderline MR (n = 124), and controls (n = 334) from an iodine deficiency area in China. The allelic and genotypic distribution of individual locus did not significantly differ among three groups with Mantel-Haenszel χ (2) test (P > 0.05). However, frequencies of haplotype of -491A/-427T/-219T/ε4 were distributed as MR > borderline MR > controls (P uncorrected = 0.004), indicating that the presence of this haplotype may increase the risk of disease.
  
  
  CONCLUSIONS
  In this large population-based study in children, we did not find any significant association between single locus of the four common ApoE polymorphisms (-491A/T, -427T/C, -219T/G, and ε2/3/4) and MR or borderline MR. However, we found that the presence of ATTε4 haplotype was associated with an increased risk of MR and borderline MR. Our present work may help enlarge our knowledge of the cognitive role of ApoE across the lifespan and the mechanisms of human cognition.
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China ; Institute for Neuropsychiatric Science and Metabonomics, Changning Mental Health Center, Shanghai 200335, China.
authors.forename: Jun
authors.identifier: 0000-0002-3126-3271
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Institute of Population and Health, Northwest University, Xi'an 710069, China.
authors.forename: Fuchang
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Neurology, the 148th Hospital, Zibo, Shandong 255300, China.
authors.forename: Yunliang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Shanghai Institute of Planned Parenthood Research, 200013, Shanghai, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China.
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Xing
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Qian
authors.affiliation: Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of Chinese Academy Sciences, Shanghai 200031, China.
authors.forename: Tingwei
authors.initials: T
authors.lastname: Guo
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Institute of Population and Health, Northwest University, Xi'an 710069, China.
authors.forename: Xiaocai
authors.initials: X
authors.lastname: Gao
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China ; Institute for Neuropsychiatric Science and Metabonomics, Changning Mental Health Center, Shanghai 200335, China ; Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of Chinese Academy Sciences, Shanghai 200031, China.
authors.forename: Lin
authors.initials: L
authors.lastname: He
authors.affiliation: Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China ; Institute for Neuropsychiatric Science and Metabonomics, Changning Mental Health Center, Shanghai 200335, China ; Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of Chinese Academy Sciences, Shanghai 200031, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Gao
mesh_terms: D000293:Adolescent; D001057:Apolipoproteins E / Q000235:genetics*; D001483:Base Sequence; D002648:Child; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D056726:Genetic Association Studies; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D015994:Incidence; D008607:Intellectual Disability / Q000235:genetics*; D007455:Iodine / Q000172:deficiency*; D008297:Male; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors
chemical_list: D001057:Apolipoproteins E; D005819:Genetic Markers; D007455:Iodine