한국인 자폐스펙트럼장애에서 Glutamate Receptor, Ionotropic, N-methyl-D-Aspartate 2B(GRIN2B) 유전자 다형성-가족기반연구 = Polymorphisms in Glutamate Receptor, Ionotropic, N-methyl-D-aspartate 2B(GRIN2B) Genes of Autism Spectrum Disorders in Korean Population : Family-based Association Study

국문 초록 (Abstract)

목 적: 본 연구의 목적은 자폐스펙트럼장애를 가진 아동들과 그 부모로 이루어진 trio를 대상으로 이 장애와 NMDA 수용체 유전자, 그 가운데 GRIN2B 유전자와의 관련성을 규명하고자 하는 것이다. 방 법: 발달지연을 주소로 가천의대 길병원과 경상대학교병원 소아정신과 외래를 내원한 아동을 선별 대상으로 하였다. DSM-IV 진단체계를 이용하여 2명의 소아정신과 의사가 자폐 스펙트럼 장애로 진단한 아동이 일차적인 연구 대상으로 선별되었다. 선별된 아동과 부모들에게는 한국판 자폐증 진단 관찰 스케줄(Autism Diagnostic Observation Schedule, 이하 ADOS) 및 자폐증 진단 면담-개정판(Autism Diagnostic Interview-Revised, 이하 ADI-R)를 실시하였다. PCR-RFLP법을 이용, GRIN2B 유전자에서 모두 4개의 단일 염기 다형성을 분석하였다(rs7301328, rs1806201, rs1805247, rs1805502). 각각의 SNPs에 대한 allelic association 을 평가하기 위하여 TDT 방법이 시행되었으며, 이를 통해 자폐장애 아동이 부모로부터 후보유전자의 특정 alleles들을 유의하게 더 많이 전달받았는지의 여부를 관찰한 뒤 McNemar chi-square test(df=1)에 의거하여 분석하였다. 결 과: 1) 연구 대상군의 특성 : 총 126명의 자폐 스펙트럼장애 아동과 그들의 생물학적 부모가 최종 분석 대상에 포함되었다. 전체 대상자 중 109명(86.5%)이 남아였으며 여아는 17명(13.5%)으로, 남아 대 여아의 비율은 6.41:1이었다. 대상군의 진단 분포는 자폐장애 107명(85.1%), 달리 분류되지 않는 전반적 발달장애(PDD, NOS) 17명(13.5%), 아스퍼거 씨 장애(Asperger's disorder) 2명(1.6%)이었다. 대상군 아동의 평균 연령은 $71.9{\pm}31.6$개월(range : 26~185개월)이었으며 한국판 사회성숙도 검사로 측정된 평균 사회지수(Social Quotient)는 $61.2{\pm}20.6$(range : 23.1~126), 측정 가능한 아동들의 평균 지능은 $65.0{\pm}27.7$(range : 25~126)이었다. K-CARS 점수는 $31.5{\pm}5.4$(range 18.5~46)로 나타났다. 2) 유전자 분석 : 분석한 GRIN2B 유전자의 4개 SNPs 가운데 하나의 SNP(rs1805247)에서 의미 있는 allelic transmission의 차이를 보였다. 이 SNP에서 transmission ratio(transmitted alleles/non-transmitted alleles)는 A allele과 G allele에서 각각 2.03과 .49로, A allele이 G allele에 비해 부모로부터 환자군에게 더 빈번하게 전달(preferential transmission) 되었음이 확인되었다(TDT ${\chi}^2$=12.89, p=.0003). 이는 Bonferroni correction 후에도 여전히 유의미한 수준을 유지하였다(p=.0009). 기타 3개의 SNP(rs7301328, rs1806201, rs1805502) 들에서는 의미 있는 transmission의 차이가 나타나지 않았다(p<.05). 결 론: 본 연구에서 GRIN2B 유전자의 단일유전자 다형성과 자폐스펙트럼장애 사이에 유의한 연관성을 보였다. 이는 glutamate NMDA 2B수용체 유전자가 이 질환의 발생에 관여할 가능성을 시사하는 것이라 생각된다.

다국어 초록 (Multilingual Abstract)

Objectives : Autism is a complex neurodevelopmental spectrum disorder with a strong genetic component. Previous neurochemical and genetic studies suggested the possible involvement of glutamate N-methyl-D-aspartate(NMDA) receptor in autism. The aim of study was to investigate the association between the NMDA2B receptor gene(GRIN2B) and autism spectrum disorders(ASD) in the Korean population. Methods : The patients with ASD were diagnosed with Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule based on DSM-IV diagnostic classification. The present study was conducted with the detection of four single nucleotide polymorphisms(SNPs) in GRIK2 and family-based association analysis of the single nucleotide polymorphisms in Korean ASD trios using transmission disequilibrium test (TDT). Results : One hundred twenty six patients with ASD and their biological parents were analyzed. 86.5% were male and 85.1% were diagnosed as autistic disorder. The mean age was $71.9{\pm}31.6$ months(range : 26-185 months). We found that rs1805247 showed significantly preferential transmission(TDT ${\chi}^2$=12.8, p<0.001) in ASD. Conclusion : One SNP in GRIN2B gene was significantly associated with ASD in the Korean population. This result suggests the possible involvement of glutamate NMDA receptor gene in the development of ASD.

참고문헌 (Reference)

1 Buckley ST, "receptor beta isoform protein expression in human alcoholic brain interaction with genotype" 2006

2 Pizzuti A, "mRNA distribution in adult human brain of GRIN2B, a N-methyl-D-aspartate (NMDA) receptor subunit" 239 : 49-53, 1997

3 Di Maria E, "Variations in the NMDA receptor subunit 2B gene (GRIN2B) and schizophrenia: a case-control study" 128 : 27-29, 2004

4 Polleux F, "Toward a developmental neurobiology of autism" 10 : 303-317, 2004

5 Serajee FJ, "The metabotropic glutamate receptor 8 gene at 7q31:partial duplication and possible association with autism" 40 : 2003

6 Lauritsen M, "The genetics of autism" 103 : 411-427, 2001

7 Nilsson M, "The dopaminergic stabiliser ACR16 counteracts the behavioural primitivization induced by the NMDA receptor antagonist MK-801 in mice:implications for cognition" 28 : 677-685, 2004

8 Willemsen-Swinkels SH, "The autistic spectrum:subgroups,boundaries,and treatment" 25 : 811-836, 2002

9 Spielman RS, "The TDT and other family-based tests for linkage disequilibrium and association" 59 : 983-989, 1996

10 Loftis JM, "The N-methyl-D-aspartate receptor subunit NR2B: localization, functional properties, regulation, and clinical implications" 97 : 55-85, 2003

11 Laurie DJ, "Regional,developmental and interspecies expression of the four NMDAR2 subunits,examined using monoclonal antibodies" 51 : 23-32, 1997

12 Moreno-Fuenmayor H, "Plasma excitatory amino acids in autism" 37 : 113-128, 1996

13 Aldred S, "Plasma amino acid levels in children with autism and their families" 33 : 93-97, 2003

14 Cull-Candy SG, "NMDA receptor diversity in the cerebellum:identification of subunits contributing to functional receptors" 37 : 1369-1380, 1998

15 Martucci L, "N-methyl-D-aspartate receptor NR2B subunit gene GRIN2B in schizophrenia and bipolar disorder:Polymorphisms and mRNA levels" 84 : 214-221, 2006

16 Ohtsuki T, "Mutation analysis of the NMDAR2B(GRIN2B)gene in schizophrenia" 6 : 211-216, 2001

17 Comings DE, "Multivariate analysis of associations of 42 genes in ADHD, ODD and conduct disorder" 58 : 31-40, 2000

18 Andres C, "Molecular genetics and animal models in autistic disorder" 57 : 109-119, 2002

19 Mohn AR, "Mice with reduced NMDA receptor expression display behaviors related to schizophrenia" 98 : 427-436, 1999

20 Ramoz N, "Linkage and association of the mitochondrial aspartate/glutamate carrier SLC25A12 gene with autism" 161 : 662-669, 2004

21 Jamain S, "Linkage and association of the glutamate receptor 6 gene with autism" 7 : 302-310, 2002

22 Kim SK, "Korean Vineland Social Maturity Scale" Chung-Ang Jeokseong Press 2002

23 Park KS, "Korean Educational Developmental Institute-Wechsler Intelligence Scale for Children" Korean Educational Development Institute 2002

24 Folstein S, "Infantile autism:a genetic study of 21 twin pairs" 18 : 297-321, 1977

25 Shinohe A, "Increased serum levels of glutamate in adult patients with autism" 2006

26 Kubota T, "Identification of two novel mutations in the OCRL1 gene in Japanese families with Lowe syndrome" 54 : 199-202, 1998

27 Carlsson ML, "Hypothesis: Is infantile autism a hypoglutamatergic disorder? Relevance of glutamate - serotonin interactions for pharmacotherapy" 105 : 525-535, 1998

28 Riedel G, "Glutamate receptor function in learning and memory" 140 : 1-47, 2003

29 Szatmari P, "Genetics of autism:overview and new directions" 28 : 351-368, 1998

30 Folstein SE, "Genetics of autism:complex aetiology for a heterogeneous disorder" 2 : 943-955, 2001

31 Smalley SL, "Genetic influences in childhood-onset psychiatric disorders:autism and attention-deficit/hyperactivity disorder" 60 : 1276-1282, 1997

32 Shuang M, "Family-based association study between autism and glutamate receptor 6 gene in Chinese Han trios" 131 : 48-50, 2004

33 American Psychiatric Association, "Diagnostic and Statistical Manual of Mental Disorders" American Psychiatric Press 1994

34 Dawson G, "Defining the broader phenotype of autism:genetic,brain,and behavioral perspectives" 14 : 581-611, 2002

35 Barnby G, "Candidate-gene screening and association analysis at the autism-susceptibility locus on chromosome 16p:evidence of association at GRIN2A and ABAT" 76 : 950-966, 2005

36 Fallin MD, "Bipolar I disorder and schizophrenia: a 440-single-nucleotide polymorphism screen of 64 candidate genes among Ashkenazi Jewish case-parent trios" 77 : 918-936, 2005

37 Lamb JA, "Autism:recent molecular genetic advances" 9 : 861-868, 2000

38 Belmonte MK, "Autism as a disorder of neural information processing directions for research and targets for therapy" 9 : 646-663, 2004

39 Myhr G, "Autism and other pervasive developmental disorders:exploring the dimensional view" 43 : 589-595, 1998

40 Smalley SL, "Autism and genetics" 45 : 953-961, 1988

41 Lord C, "Autism Diagnostic Observation Schedule" Western Psychological Services 2000

42 Lord C, "Autism Diagnostic Interview-Revised:a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders" 24 : 659-685, 1994

43 Berney TP, "Autism - an evolving concept" 176 : 20-25, 2000

44 Kim JH, "Association study of polymorphisms in N-methyl-d-aspartate receptor 2B subunits gene with Korean alcoholism" 2006

45 Hong CJ, "Association analysis for NMDA receptor subunit 2B(GRIN2B)genetic variants and psychopathology and clozapine response in schizophrenia" 11 : 219-222, 2001

46 Qin S, "An association study of the N-methyl-D-aspartate receptor NR1 subunit gene in schizophrenia with universal DNA microarray" 13 : 807-814, 2005

47 Yonan AL, "A genomewide screen of 345 families for autism-susceptibility loci" 73 : 886-897, 2003

48 Nilsson M, "A behavioural pattern analysis of hypoglutamatergic mice - effects of four different antipsychotic agents" 108 : 1181-1196, 2001