CYP11A1基因单核苷酸多态性在宁夏回、汉族人群中的分布特征

目的 了解宁夏人群中CYP11A1基因rs16968477、rs1843090、rs4077582、rs9806234和rs12438594位点遗传多态的分布情况,并分析该位点在不同种族间的分布差异.方法 研究对象为宁夏医科大学体检健康学生559例,其中回族273例,汉族286例.单核苷酸多态性采用TaqMan Gene Typing技术检测.结果 宁夏回、汉族人群CYP11A1基因多态位点等位基因频率分别为rs16968477(C/T:64.47％/35.53％;68.53％/31.47％);rs1843090(A/G:46.15％/53.85％;43.53％/56.47％);rs4077582(C/T:56.78％/43.22％;55.24％/44.76％);rs9806234(A/G:32.78％/67.22％;38.99％/61.01％);rs12438594(A/G:47.44％/52.56％;42.48％/57.52％).宁夏人群各多态性基因型总体分布与HAPMAP结果比较,rs16968477、rs9806234位点与欧洲人群和非洲人群不同(P=0.017、0.001、0.000、0.000);rs1843090位点与欧洲人群、日本人群和非洲人群不同(P=0.000、0.011、0.000);rs4077582、rs12438594位点与欧洲人群不同(P=0.000、0.000).结论 CYP11A1基因5个单核苷酸多态性在宁夏回、汉族之间差异无统计学意义;5位点的基因型总体分布在种族和地区间差异具有统计学意义.     

神经丛蛋白A2(PLXNA2)基因多态性与精神分裂症的关联研究

目的:探讨神经丛蛋白(PLXNA2)基因与汉族人群精神分裂症的关联。方法:采用DNA测序检测方法,依据ICD-10诊断标准,在735例汉族精神分裂症住院患者和1316例年龄、性别匹配的正常对照者中,探索PLXNA2基因5个单核苷酸多态性(SNP)位点与精神分裂症的关联。结果:PLXNA2基因的4个SNPs位点与精神分裂症关联(均P<0.05);由rs3811383-rs841865-rs2785622组成的单体型ATT及由rs841865-rs752016组成的单体型AC与精神分裂症关联(均P<0.05)。结论:本研究结果提示PLXNA2基因多态性在中国汉族人群中与精神分裂症关联。     

BAIAP2基因多态与儿童注意缺陷多动障碍共患学习困难的关联分析

目的:探讨脑特异性血管发生抑制剂1相关蛋白2(BAIAP2)基因多态与儿童注意缺陷多动障碍(ADHD)共患学习困难(LD)的关联。方法:选取符合美国精神障碍诊断与统计手册第4版(DSM-IV)诊断标准731例共患LD的ADHD儿童和957例健康对照,采用高通量实时荧光定量PCR方法检测基因型,探讨BAIAP2基因的9个单核苷酸多态性(SNPs)位点与共患LD的儿童ADHD的关联。结果:BAIAP2的SNP位点rs8079626/G(病例对照频率0.638 vs.0.604)和rs4969385/T(0.179 vs.0.150)与儿童ADHD共患LD关联,rs3934492/C(0.572 vs.0.532)和rs4969385/T(0.180 vs.0.142)与男性儿童ADHD共患LD关联,rs4969239/G(0.426 vs.0.329)和rs4969358/A(0.472 vs.0.389)与女性儿童ADHD共患LD关联(均P0.05);由rs4969239-rs4969358-rs6565531-rs8079626组成的单体型AAGG与共患LD的儿童ADHD共患LD(0.100 vs.0.065)和男性儿童ADHD共患LD(0.101 vs.0.065)关联(均P0.05)。结论:BAIAP2基因多态性可能与汉族儿童ADHD共患LD的病理机制有关,且这种作用机制可能存在性别差异。     

TMX基因多态性与先天性肥厚性幽门狭窄易感性的传递不平衡检验分析

目的 探索TMX基因外显子6上的多态性位点rs7161242[ c.492T＞G]及外显子7上的多态性位点rs7160810[ c.648 G＞A]与先天性肥厚性幽门狭窄(CHPS)发病易感性的关联.方法 对广州市第一人民医院收治的22个汉族核心家系(CHPS患者及父母)采用PCR及测序的方法进行基因分型.应用传递不平衡检验(TDT)判断基因多态性与CHPS发病的关联.结果 测序结果未发现新的突变位点;患儿及父母组内这两个多态性位点的Hardy-Wcinberg平衡检验均P＞0.05.TDT检验提示多态性位点rs7161242的G等位基因及rs7160810的A等位基因均与CHPS发病相关,其p值分别为2.0×10-4和5.699x10-5.连锁不平衡分析结果提示,这两个位点的r2为0.757,D′值为0.893,成紧密连锁.结论 TMX基因的多态性位点rs7161242[ c.492T＞G]及rs7160810[c.648 G＞A]与中国汉族人群CHPS发病密切相关.     

西北地区汉族人群FCAMR基因单核苷酸多态性及单体型分析

为研究西北地区汉族人群IgAIg MFc高亲和力受体(Fc receptor IgAIg Mhigh affinity,FCAMR/Fcα/μR)基因单核苷酸多态性(SNP)及单体型的频率。我们采用聚合酶链反应后直接测序方法,对西北地区79(男45,女34)名没有亲缘关系的汉族健康个体FCAMR基因,T549C(rs1856746),A457G(rs3813952),G421A(rs1340232)和A298G(rs3813950)4个SNP位点进行基因分型。用SHEsis软件分析FCAMR基因的单体型频率。本研究发现西北地区汉族人群中T549C(rs1856746)位点,等位基因频率C是38.6%,T是61.4%;A457G(rs3813952)位点,等位基因频率G是5.7%,A是94.3%;G421A(rs1340232)位点,等位基因频率A是17.1%,G是82.9%,A298G(rs3813950)位点,等位基因频率G是4.4%,A是95.6%。西北地区汉族人群中FCAMR基因T549C(rs1856746)、A457G(rs3813952)、G421A(rs1340232)和A298G(rs3813950)4个位点构成的3种主要单体型率(频率>10%)T/A/G/A是60.5%,C/A/A/A是17.1%和C/A/G/A是16.7%。本研究分析了西北地区汉族人群FCAMR基因T549C(rs1856746)、A457G(rs3813952)、G421A(rs1340232)和A298G(rs3813950)4个SNP位点的基因型频率、等位基因频率和单体型频率,为研究该地区FCAMR基因单核苷酸多态性与免疫反应以及相关疾病如IgA肾病易感性之间的相关性提供研究基础。     

FXYD6基因遗传多态性在精神分裂症患者核心家系中的传递不平衡检验

目的 探讨FXYD6基因单核苷酸多态性(single nucleotide polymorphisms,SNP)和精神分裂症(schizophrenia)之间的相关性.方法 采用等位基因特异性PCR的方法对FXYD6基因6个SNPs(rs10790212、rs11544201、rs555577、rs1815774、rs4938446和rs497768)位点的基因型在101个三口之家中进行传递不平衡检验(transmission disequilibrium test,TDT).结果 遗传标记rs10790212和rs11544201显示了显著的传递不平衡(P＜0.05),而单倍型分析的结果表明单倍型rs10790212-rs11544201与精神分裂症显著性关联(P＜0.05).结论 FXYD6基因与中国汉族人群精神分裂症遗传易感性相关,有必要进一步开展对FXYD6基因的功能学研究.     

中国汉族人群γ-氨基丁酸A类受体基因簇与孤独症的关联研究

目的:探讨染色体15q12区域γ-氨基丁酸A类受体基因簇的单核苷酸多态性与中国汉族孤独症人群的遗传关联。方法:选取502个中国汉族孤独症核心家系(包括502例患者及健康的生物学父母1004例),孤独症儿童符合美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)孤独症诊断标准。通过Agena Bioscience质谱检测平台,对γ-氨基丁酸A类受体基因簇中GABRB3、GABRA5和GABRG3基因的15个标签单核苷酸多态性位点进行基因分型。在孤独症核心家系中进行以家系为基础的关联检验,比较父母携带的杂合型等位基因传递给孤独症子代的概率。结果:位于GABRG3基因单核苷酸多态性位点rs7180500的等位基因C和位于GABRB3基因单核苷酸多态性位点rs4906902的等位基因A存在父母向孤独症子代的优先传递(Z=3.573,P0.001;Z=3.141,P=0.002);经Bonferroni校正后仍具有统计学意义。结论:在中国汉族人群中,位于染色体15q12区域的GABRG3和GABRB3基因可能是孤独症的易感基因。     

云南汉族人群IL-4基因5’和3’非编码区域多态性与HCV慢性感染无相关性

目的探讨IL-4基因5’和3’非编码区域单核苷酸多态性位点(single nucleotide polymorphism,SNP)与HCV慢性感染的相关性。方法选取云南地区汉族人群HCV慢性感染患者380例,健康体检人群439例。采用Taq Man探针基因分型方法对IL-4基因5’和3’非编码区域6个SNP位点SNP-1138A/G(rs2243247)、-1098G/T(rs2243248)、-589C/T(rs2243250)、-33C/T(rs2070874)、2979C/A(rs2227284)、3’端C/T(rs2243292)进行基因分型,并构建单倍型,评估上述6个SNP位点及单倍型与HCV慢性感染的相关性。结果 IL-4基因SNP-1138A/G(rs2243247),3’端C/T(rs2243292)在病例组和对照组中无多态性;SNP位点-1098G/T(rs2243248)、-589C/T(rs2243250)、-33C/T(rs2070874)、2979C/A(rs2227284)的基因型频率和等位基因频率在病例组和对照组中差异无统计学意义(P0.05);单倍型分析结果显示:SNP位点-1098G/T(rs2243248)、-589C/T(rs2243250)、-33C/T(rs2070874)、2979C/A(rs2227284)构建的单倍型频率在病例组和对照组中差异无统计学意义(P0.05)。结论在云南汉族群体中,IL-4基因5’和3’非编码区域SNP位点-1138A/G(rs2243247)、-1098G/T(rs2243248)、-589C/T(rs2243250)、-33C/T(rs2070874)、2979C/A(rs2227284)、3’端C/T(rs2243292)与HCV慢性感染没有相关性。     

儿茶酚-O-甲基转移酶基因单核苷酸多态性位点与精神分裂症的关联研究

目的 探讨儿茶酚-O-甲基转移酶(catechol-O-methyl transferanse,COMT)基因8个单核苷酸多态性位点(single nRcleotide polymorphism,SNP)与粤东潮汕地区精神分裂症的关系.方法 应用聚合酶链式反应-聚丙烯酰胺凝胶芯片技术检测COMf基因的8个SNP位点(rs4680、rs4818、rsl65599、rs737865、rs2075507、rs6267、rs6269、rs4633)在粤东潮汕地区的279例精神分裂症患者和100名健康对照中的分布,并借助于plink软件对所得数据进行关联分析.结果 单个位点等位基因频率在两组间的分布差异无统计学意义;单倍型(G)-G-A-A[(rs4680)-rsl65599-rs2075507-rs6269]和单倍型A-A-C-(G)[rs2075507-rs6269-rs4633-(rs6267)]频率两组分布差异有统计学意义,精神分裂症组低于正常对照组,提示它们可能是精神分裂症的保护因素.结论 在中国粤东地区汉族人群中,COMT基因的8个SNP位点(rs4680、rs4818、rsl65599、rs737865、rs2075507、rs6267、rs6269、rs4633)与精神分裂症无关联性,其中的两个单倍型可能是精神分裂症的保护因素.但本研究不能排除COMT基因可能存在其他功能性变异位点与精神分裂症相关.     

儿茶酚-O-甲基转移酶基因单核苷酸多态性位点与精神分裂症的关联研究

目的 探讨儿茶酚-O-甲基转移酶(catechol-O-methyl transferanse,COMT)基因8个单核苷酸多态性位点(single nRcleotide polymorphism,SNP)与粤东潮汕地区精神分裂症的关系.方法 应用聚合酶链式反应-聚丙烯酰胺凝胶芯片技术检测COMf基因的8个SNP位点(rs4680、rs4818、rsl65599、rs737865、rs2075507、rs6267、rs6269、rs4633)在粤东潮汕地区的279例精神分裂症患者和100名健康对照中的分布,并借助于plink软件对所得数据进行关联分析.结果 单个位点等位基因频率在两组间的分布差异无统计学意义;单倍型(G)-G-A-A[(rs4680)-rsl65599-rs2075507-rs6269]和单倍型A-A-C-(G)[rs2075507-rs6269-rs4633-(rs6267)]频率两组分布差异有统计学意义,精神分裂症组低于正常对照组,提示它们可能是精神分裂症的保护因素.结论 在中国粤东地区汉族人群中,COMT基因的8个SNP位点(rs4680、rs4818、rsl65599、rs737865、rs2075507、rs6267、rs6269、rs4633)与精神分裂症无关联性,其中的两个单倍型可能是精神分裂症的保护因素.但本研究不能排除COMT基因可能存在其他功能性变异位点与精神分裂症相关.     

Association study of neuregulin 1 gene polymorphisms with auditory P300 in schizophrenia

Neuregulin 1 (NRG1), a gene involved with myelin production has been shown to have a positive correlation with schizophrenia. Event-related potentials (ERPs) studies provide the evidence of disturbed electrophysiologic marker in schizophrenia. The present study investigated the association of NRG1 genotypes with P300 in schizophrenia. Three polymorphisms in NRG1 gene were detected in 287 Chinese Han schizophrenics and 120 healthy control subjects. Among the total sample, 140 patients and 96 controls underwent P300. There were no significant differences for genotype distributions and allele frequencies between schizophrenic group and the control. A significant difference was observed between the schizophrenic patients and controls in the AT haplotype, with Odds Ratio 0.304 (P = 0.000882, 95% CI = 0.145-0.636). P300 amplitude in the schizophrenic group was significantly lower than that of the controls at Fz, Cz, Pz. P300 latency in the schizophrenic group was also significantly longer than that of the controls at Cz, Pz, Fz. Significant differences of P300 latency between three genotypes of rs3924999 were found at Cz and Pz both in schizophrenic group and the controls. The G/G carriers of rs3924999 tended to perform worse in the P300 latency as compared to A/A or A/G carriers both in the schizophrenia and controls. There were no significant differences for P300 latency and amplitude between schizophrenic group and controls for AT haplotype. NRG1 gene is a susceptible gene for Chinese Han schizophrenia and AT haplotype might have the protective role in the schizophrenia. Rs3924999 in NRG1 gene might functionally impact cognitive processing.     

The transmission disequilibrium analysis between neuronal nicotinic acetylcholine receptor alpha 7 subunit gene polymorphisms and schizophrenia]

OBJECTIVE: To investigate the association between neuronal nicotinic acetylcholine receptor alpha 7 subunit (CHRNA7) gene and schizophrenia. METHODS: The three polymorphisms rs2337980, rs1909884, rs883473 in CHRNA7 gene were detected based on PCR and polyacrylamide gel microarray in 129 schizophrenic trios. The results of genotyping were analyzed by haplotype relative risk analysis based on haplotype(HHRR), transmission disequilibrium test(TDT) and hyplotype analysis. RESULTS: (1)The HHRR analysis suggested that there was significant differences in rs2337980 allele frequencies between schizophrenia group and dummy control group(P= 0.017); (2)In TDT test, there may be transmission disequilibrium between rs2337980 and schizophrenia, the heterozygous parents excessively transferred the C allele to patients (P= 0.021); (3)The haplotype between rs2337980 and rs1909884 as well as the hyplotype among rs2337980, rs1909884 and rs883473 may have significant association with schizophrenia (global P= 0.034; global P= 0.027), the T-C and T-C-T hyplotype may have transmission disequilibrium with schizophrenia. CONCLUSION: There may be association between CHRNA7 gene polymorphisms and schizophrenia, the variant allele T in rs2337980 may have a protective effect to schizophrenia.     

A combined effect of the KPNA3 and KPNB3 genes on susceptibility to schizophrenia

Recent studies suggest that both the KPNB3 gene and the KPNA3 gene in the long arm of chromosome 13 (13q) are associated with schizophrenia. Because these two genes belong to the same family of karyopherins, their combined effect on illness was investigated among 238 Chinese family trios consisting of fathers, mothers and affected offspring with schizophrenia. We detected three single nucleotide polymorphisms (SNPs), including rs626716 at the KPNB3 locus, and rs3782929 and rs3736830 at the KPNA3 locus. The transmission disequilibrium test (TDT) showed allelic association for rs626716 (X2=10.77, P=0.001) and for rs3782929 (X2=4.89, P=0.027) but not for rs3736830 (X2=0.29, P=0.59). Although the conditional test did not show association either for the rs626716-rs3782929 combinations (X2=1.329, d.f.=2, P=0.514) or for the rs626716-rs3736830 combinations (X2=0.606, d.f.=2, P=0.739), the 1-d.f. test showed association for the rs626716(C)-rs3782929(G) combination (X2=10.79, P=0.001) and for the rs626716(C)-rs3736830(G) combination (X2=8.64, P=0.003). The present work suggests that the combination of the KPNA3 gene and the KPNB3 gene may increase a genetic risk for schizophrenia.     

神经型烟碱乙酰胆碱受体α7亚单位基因多态性与精神分裂症的传递不平衡研究

目的 探讨神经型烟碱乙酰胆碱受体α7亚单位基因(neuronal nicotinic acetyleholine receptor α7 subunit gene,CHRNA7)多态性与精神分裂症的关系.方法 应用聚合酶链反应及聚丙烯酰胺凝胶芯片技术检测129个精神分裂症先证者核心家系CHRNA7基因的rs2337980、rs1909884、rs883473三个单核苷酸多态性,并采用基于单倍型的单倍型相对风险检验(haplotype relative risk,HHRR)、传递不平衡检验(transmission disequilibrium test,TDT)及单倍型分析进行统计.结果 (1)HHRR分析结果显示rs2337980位点精神分裂症患者组与虚拟对照组之间等位基因频率差异有统计学意义(P=0.017);(2)TDT分析发现,rs2337980位点与精神分裂症之间可能存在传递不平衡,杂合子父母过多的传递等位基因C给患病子女(P=0.021).(3)单倍型分析发现,rs2337980、rsl909884及rs2337980、rsl909884、rs883473组成的单倍型与精神分裂症有显著相关(总体P=0.034;glohal P=0.027),其中T-C,T-C-T两个单倍型与精神分裂症可能存在传递不平衡.结论 CHRNA7 基因多态性可能与精神分裂症存在关联,rs2337980的变异等位基因T可能是精神分裂症的保护性因子.     

Neuregulin 1 gene and variations in perceptual aberration of schizotypal personality in adolescents

BACKGROUND: We test the hypothesis that the neuregulin 1 (NRG1 ) gene at chromosome 8p22-p12, which has been implicated as a susceptibility gene to schizophrenia, is associated with variations in schizotypal personality in non-clinical populations. METHOD: A randomly selected sample of 905 adolescents were assessed for their personality features using the Perceptual Aberration Scale (PAS) and the Schizotypal Personality Questionnaire (SPQ) and genotyped for three single nucleotide polymorphisms (SNP8NRG221533, rs3924999, and rs2954041) at the NRG1 gene. Relations between the three genetic variants and continuous schizotypal personality scores were evaluated using ANOVA for single-locus analyses and haplotype trend regression test for multi-locus analyses. RESULTS: Single locus analysis showed that the A allele of rs3924999, a functional polymorphism in exon 2, had the largest effect size and exhibited a prominent allele-dose trend effect for the PAS score. Haplotype analyses using the haplotype trend regression test indicated that the A allele of rs3924999 was mainly responsible for the association with the PAS but not with the SPQ or its three factors, and the magnitude of significance was not strengthened by the combination of this allele with adjacent locus. CONCLUSIONS: Our study provides the first evidence for the association of NRG1 with schizotypal personality and indicates a possible role of NRG1 in the genetic etiology of schizophrenia through perceptual aberrations.     

A study of the PEMT gene in schizophrenia

The phospholipid hypothesis of schizophrenia is becoming popular because of the findings from the niacin flush test, the treatment with polyunsaturated fatty acids (PUFAs), biochemical studies for the phospholipid metabolism pathway and genetic studies of phospholipase A2. The present study attempted to investigate the gene coding for phosphatidylethanolamine N-methyltransferase (PEMT), which is an important enzyme for the synthesis of membrane phospholipids. We recruited 271 Chinese parent-offspring trios of Han descent and detected 3 single nucleotide polymorphisms (SNPs) at the PEMT locus. The transmission disequilibrium test (TDT) showed allelic association for rs464396 (X2=9.4, P=0.002), but not for the other two. The 2-SNP haplotype analysis showed haplotypic association for both the rs936108-rs464396 haplotypes (X2=25.7, d.f.=3, P=0.00001) and the rs464396-rs4244593 haplotypes (X2=17.3, d.f.=3, P=0.0006). The 3-SNP haplotype analysis also showed a haplotypic association (X2=24.4, d.f.=7, P=0.0006). The present results suggest that the PEMT gene may contribute to the etiology of schizophrenia.     

Cytosolic PLA2 genes possibly contribute to the etiology of schizophrenia.

The present study detected three single nucleotide polymorphisms (SNPs), BanISNP at the PLA2G4A locus, rs1648833 at the PLA2G4B locus, and rs1549637 at the PLA2G4C locus, to investigate a genetic association between the cytosolic PLA2 (cPLA2) genes and schizophrenia. A total of 240 Chinese parent-offspring trios of Han descent were recruited for the genetic analysis. The transmission disequilibrium test (TDT) showed allelic association for rs1549637 (chi(2) = 5.68, uncorrected P = 0.017), but not for BanISNP and rs1648833. The conditioning on genotype (COG) test revealed a disease association for the BanISNP-rs1648833 combination (chi(2) = 12.54, df = 3, P = 0.0057) and for the BanISNP-rs1549637 combination (chi(2) = 9.72, df = 2, P = 0.021), but the conditioning on allele (COA) test did not show such an association for the above two combinations. Neither the COA test nor the COG showed a disease association for the rs1648833-rs1549637 combination. In the combination of all three SNPs, the COG test, but not the COA test, showed a strong association (chi(2) = 22.93, df = 6, P = 0.0008). These findings suggest that these three cPLA2 genes may all be involved in contributing to the etiology of schizophrenia although their effect size appears to be relatively small.     

精神分裂症与KCNN3基因1137～1140缺失移码突变传递不平衡研究

目的 探讨KCNN3基因1137～1140的4个碱基缺失所致移码突变与精神分裂症的关系。方法 95个核心家系共289名家庭成员，包含107例精神分裂症患者纳入本研究。精神分裂症采用CCMD-Ⅱ-R诊断标准。KCNN3基因1137～1140的4个碱基缺失基因型检测使用PCR技术和限制性内切酶DdeI消化方法。精神分裂症与KCNN3基因1137～1140缺失4个碱基的关联分析采用基于单倍型的单倍型相对风险率和传递／不平衡检验。结果 患者组与正常父母组比较，KCNN3基因1137～1140的4个碱基缺失的基因型频数和等位基因频率分布差异无统计学意义（χ^2=0．253，P〉0．05和χ^2＝0．010，P〉0．05）。基于单倍型的单倍型相对风险分析发现父母传递与不传递给患者的KCNN3基因等位基因之间差异无统计学意义（χ^2=0．042，P〉0．05）。传递不平衡检验结果发现KCNN3基因等位基因传递不存在连锁不平衡（χ^2=3．000，P＝0．0833）。结论 本组研究对象中，KCNN3基因第1外显子1137～1140的4个碱基缺失的发生率少；分析结果提示KCNN3基因第1外显子1137～1140的4个碱基缺失的等位基因与精神分裂症无关联。     

The serotonin 5-HT1D receptor gene and attention-deficit hyperactivity disorder in Chinese Han subjects.

Attention-deficit/hyperactivity disorder (ADHD) is a heritable disease. Serotonin is one of the neurotransmitters involved in the etiology of ADHD. Serotonin-1D receptors are autoreceptors which can regulate the release of serotonin in brain, so the HTR1D gene may be predisposing. The current study genotyped two variants of HTR1D gene in 272 ADHD trios of Chinese ethnicity, that is 1350T > C in the coding region and 1236A > G in 3'-UTR by the use of transmission disequilibrium test (TDT). The A allele of the 1236A > G polymorphism exhibited both a trend toward preferential transmission to ADHD probands (chi2 = 3.815, P = 0.051) and a significant preferential transmission to probands of ADHDC (chi2 = 4.198, P = 0.040). Additional polymorphisms in this gene need to be studied further.     

Possible association of a cholecystokinin promoter variant to schizophrenia

Several lines of research indicate a cholecystokinin (CCK) deficit in schizophrenia patients. A C to T substitution was found in the promoter region of the CCK gene. We investigated this promoter variant in patients with schizophrenia and geographically-matchedcontrols. The T allele was detected in 24% of the 85 schizophrenics and 16% of the 247 controls. No significant difference in the T allele frequency was found between patients and controls (chi(2) = 2.77, P > 0.1). The schizophrenia sample was analyzed further along the dimensions of positive and negative symptoms. The patients with prominent negative symptoms presented a statistically significant association to the T allele (chi(2) = 4.13, P < 0.04). However, the significance disappeared after the Bonferroni correction (P > 0.15). Since the case-control analysis may present incorrect ethnic match between cases and controls, we applied the family-based tests to verify the above findings. Both transmission disequilibrium test (TDT; chi(2) = 5.33, P < 0.025 in 12 trios) and haplotype relative risk (HRR; chi(2) = 3.844, P < 0.05 in 60 trios) indicated a significantly high transmission of T allele to schizophrenia offspring probands from their parents. While our family-based tests seem to support the CCK involvement in schizophrenia, no definite conclusion can be drawn based on such a small sample size. This preliminary finding is subjected to future investigations.