Influence of rs2587552 polymorphism of DRD2 gene on the effect of a childhood obesity intervention: A prospective, parallel-group controlled trial / 北京大学学报(医学版)

OBJECTIVE@#To explore the association between rs2587552 polymorphism (has a strong lin-kage disequilibrium with rs1800497 which had been found in many studies to be related to obesity, r2=0.85) of DRD2 gene and the effect of a childhood obesity intervention in Chinese population, and provide a scientific basis for future personalized childhood obesity intervention based on genetic background.@*METHODS@#From a multi-center cluster randomized controlled trial studying the effect of a childhood obesity intervention, we enrolled 382 children from 8 primary schools (192 and 190 children from intervention and control groups, respectively) in Beijing as study subjects. Saliva was collected and DNA was extracted to detect the rs2587552 polymorphism of DRD2 gene, and the interactions between the gene and study arms on childhood obesity indicators [including body weight, body mass index (BMI), BMI Z-score, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio, and body fat percentage] were analyzed.@*RESULTS@#No association was found between rs2587552 polymorphism and the changes in hip circumference or body fat percentage in the intervention group (P>0.05). However, in the control group, children carrying the A allele at DRD2 rs2587552 locus showed a greater increase in hip circumference and body fat percentage compared with those not carrying A allele (P < 0.001). There were interactions between rs2587552 polymorphism of DRD2 gene and study arms on the changes in hip circumference and body fat percentage (P=0.007 and 0.015, respectively). Compared with the control group, children in the intervention group carrying the A allele at DRD2 rs2587552 locus showed decrease in hip circumference by (-1.30 cm, 95%CI: -2.25 to -0.35, P=0.007) and decrease in body fat percentage by (-1.34%, 95%CI: -2.42 to -0.27, P=0.015) compared with those not carrying A allele. The results were consistent between the dominant model and the additive model (hip circumfe-rence: -0.66 cm, 95%CI: -1.28 to -0.03, P=0.041; body fat percentage: -0.69%, 95%CI: -1.40 to 0.02, P=0.056). No interaction was found between rs2587552 polymorphism and study arms on the changes in other childhood obesity-related indicators (P>0.05).@*CONCLUSION@#Children carrying the A allele at rs2587552 polymorphism of DRD2 gene are more sensitive to intervention and showed more improvement in hip circumference and body fat percentage after the intervention, suggesting that future personalized childhood obesity lifestyle intervention can be carried out based on the rs2587552 polymorphism of DRD2 gene.

Prevalence of polymorphisms in the ANKK1, DRD2, DRD3 genes and metabolic syndrome in refractory schizophrenia / Prevalência de polimorfismos nos genes ANKK1, DRD2, DRD3 e síndrome metabólica na esquizofrenia refratária / Prevalencia de polimorfismos en los genes ANKK1, DRD2, DRD3 y síndrome metabólico en la esquizofrenia refractária

ABSTRACT Objective: to estimate the prevalence of TaqIA, -141C and rs6280 polymorphisms of the ANKK1, DRD2 and DRD3 genes and evaluate their association with the occurrence of metabolic syndrome in patients with refractory schizophrenia. Method: cross-sectional study conducted in the Extended Western Region of Minas Gerais, with refractory schizophrenic patients using the antipsychotic clozapine. Sociodemographic, clinical, anthropometric, biochemical and genetic data were collected. Univariate analysis of the data was performed. Results: seventy-two patients participated in the study and the occurrence of Metabolic Syndrome was observed in 47.2% of them. There was no association between Metabolic Syndrome and the studied polymorphisms. There was a statistically significant difference in the low HDL parameter with homozygous genotype for the C allele of the -141C polymorphism of the DRD2 gene. Conclusion: a high prevalence of MS was evidenced. The -141C polymorphism was associated with low HDL. Genetic analysis and identification of metabolic alterations in this group of patients can guide drug treatment and provide a better quality of life.

RESUMO Objetivo: estimar a prevalência dos polimorfismos TaqIA, -141C e rs6280 dos genes ANKK1, DRD2 e DRD3 e avaliar sua associação com a ocorrência de síndrome metabólica em pacientes com esquizofrenia refratária. Método: estudo de delineamento transversal, realizado na Região Ampliada Oeste de Minas Gerais, que incluiu pacientes com esquizofrenia refratária em uso do antipsicótico clozapina. Foram coletados dados sociodemográficos, clínicos, antropométricos, bioquímicos e genéticos. Realizou-se análise univariada dos dados. Resultados: participaram 72 pacientes e observou-se a ocorrência de Síndrome Metabólica em 47,2%, não sendo encontrada associação da Síndrome Metabólica com os polimorfismos estudados. Houve diferença estatisticamente significante com o parâmetro do baixo HDL com genótipo homozigoto para alelo C do polimorfismo -141C do gene DRD2. Conclusão: evidenciou-se prevalência de SM elevada. O polimorfismo -141C associou-se ao baixo HDL. A análise genética e a identificação de alterações metabólicas, neste grupo de pacientes, podem nortear o tratamento medicamentoso e propiciar melhor qualidade de vida.

RESUMEN Objetivo: estimar la prevalencia de los polimorfismos TaqIA, -141C y rs6280 de los genes ANKK1, DRD2 y DRD3 y evaluar su asociación con el síndrome metabólico en pacientes con esquizofrenia refractária. Método: estudio de delineamiento transversal, realizado en la Región Ampliada Oeste de Minas Gerais, que incluye pacientes con esquizofrenia refractária usando el antipsicótico clozapina. Fueron recogidos datos sociodemográficos, clínicos, antropométricos, bioquímicos y genéticos. Se realizó um análisis univariada de los datos. Resultados: participaron 72 pacientes y se observó el Síndrome Metabólico en 47,2%, no siendo encontrada una asociación del Síndrome Metabólico con los polimorfismos estudiados. Hubo diferencia estadísticamente significante con el parámetro del bajo HDL con genotipo homozigoto para alelo C del polimorfismo -141C del gen DRD2. Conclusión: se vio una prevalencia de SM elevada. El polimorfismo -141C se asoció al bajo HDL. El análisis genético y la identificación de alteraciones metabólicas, en este grupo de pacientes, pueden guiar al tratamiento medicamentoso y propiciar mejor calidad de vida.

Impact of COMT H108L, MAOB int 13 A>G and DRD2 haplotype on the susceptibility to Parkinson’s Disease in South Indian subjects.

In view of documented evidence demonstrating the association of dopaminergic metabolism and neurotransmission with Parkinson’s disease (PD), a case-control study was conducted to investigate the impact of particular polymorphisms in the catechol O-methyl transferase (COMT) H108L, monoamine oxidase B (MAOB) int 13 A>G, dopamine transporter 1 (DAT1) A1215G, dopamine receptor D2 (DRD2) Taq1A, DRD2 Taq1B and DRD2 Taq1D genes on the susceptibility to PD. PCR-RFLP method was used for the genetic analysis. The COMT H108L polymorphism increased PD risk by 1.4-fold (95%CI: 1.02-1.98), whereas reduced risk was observed with MAOB int 13 A>G polymorphism (OR: 0.77, 95%CI: 0.51-0.99). Multifactor dimensionality reduction analysis showed gene-gene interactions between these two loci that resulted in loss of the protective role of MAOB G-allele in the presence of COMT L-allele. DAT1A1215G polymorphism in the exon 9 was not associated with PD. Individually, DRD2 polymorphisms showed null association. However, all-variant haplotype of DRD2 locus i.e. T-G-T haplotype showed 29.8-fold risk for PD compared to all-wild haplotype i.e., C-A-C haplotype (95%CI: 6.85-130.4). To conclude, genetic variants of COMT, MAOB and DRD2 loci modulate susceptibility to PD in South Indian subjects.

Association of genetic polymorphisms of glutamate decarboxylase 2 and the dopamine D2 receptor with obesity in Taiwanese subjects

It has been proposed that glutamate decarboxylase 2 and the dopamine D2 receptor are involved in the brain reward cascade to increase carbohydrate craving and cause eating disorders. We investigated the association between the polymorphisms of the CAD2 and DRD2 genes and obesity with a higher body mass index [BMI] in Taiwanese patients. A retrospective, case-control study at Antai Tian-Sheng Memorial Hospital from 1 January to 31 December 2009. Of 300 subjects enrolled in the study, 132 were obese [BMI>30 kg/m[2]] and 168 controls were not obese [BMI

Haplotype diversity and linkage disequilibrium at the DRD2 locus among the tribes of western and southern regions of India.

BACKGROUND: Dopamine receptor D2 (DRD2) is an important gene having functional significance in the fields of neuropsychiatry and pharmacology and also has importance in evolutionary studies. MATERIALS AND METHODS: This study was undertaken to find out the haplotype distribution and linkage disequilibrium (LD) pattern for the three TaqI sites (TaqI ‘A’, TaqI ‘B’ and TaqI ‘D’) in the DRD2 gene in 232 unrelated individuals from five ethno-linguistically distinct endogamous tribal populations; Siddis and Gonds of Uttara Kannada district, Karnataka; Varli and Kolgha of Valsad district, Gujarat; and Dangi Konkana of Dang district, Gujarat. The genotype data obtained after molecular analysis of the three DRD2 sites was subjected to statistical analysis such as calculation of allele frequencies, haplotype frequencies among others. Subsequently, a neighbor-joining tree was also constructed from the data obtained. RESULTS: The three DRD2 sites were found to be polymorphic in all the populations. All the populations showed high levels of heterozygosities. Out of the eight possible haplotypes, most populations shared seven haplotypes. Of all the populations, Siddis showed the highest frequency of the ancestral haplotype B2D2A1 (11.4%). Significant LD was found to exist for TaqI ‘A’ and TaqI ‘B’ sites in both the populations. CONCLUSION: The findings are in concurrence with those from other Indian studies, especially from Dravidian-speaking South Indian populations. Similar pattern of diversity observed for ethnically and linguistically diverse populations in the present study is indicative of complex structure of Indian populations.

Linkage and association of DRD2 Gene TaqI polymorphism with schizophrenia in an Iranian population

D2 dopamine receptor gene has been reported to be one of the most relevant candidate genes in schizophrenia. In this study, we investigated the association between TaqIA and TaqIB dopamine D2 receptor polymorphisms and psychopathology of schizophrenia. The study subjects were 38 acutely exacerbated schizophrenic patients who were all Iranian descent. The control population consisted of 63 healthy individuals with almost the same age as patients and were also of Iranian decent. The TaqIA and TaqIB genotypes, the A1 and A2 alleles, and the B1 and B2 were determined by restriction fragment length polymorphism of the amplified DNA fragments by polymerase chain reaction. For each polymorphism [A or B] the patients were categorized according to their genotype into three groups; i.e. the patients with alleles A1/A1, A1/A2, A2/A2; B1/B1, B1/B2, and B2/B2. No significant association was found between Taq1A or Taq1B gene polymorphisms and schizophrenia in patients compared to the controls. When study subjects were stratified according to their gender, the distribution of the A1/A1 genotype did was significantly different in both men and women [patients vs. controls]. Our findings show that there is no genetic association between Taq1A and Taq1B gene polymorphisms and schizophrenia. Further clinical studies should be conducted to confirm and further evaluate these findings

Aspectos Genéticos do Alcoolismo / Genetic aspects of alcoholism

O termo alcoolismo refere-se aos sintomas que se desenvolvem a partir do consumo inadequado de álcool. Por ser o álcool a principal droga psicoativa utilizada no mundo, é de se esperar que o desenvolvimento da doença dependa da interaçäo entre fatores neurobiológicos e psicossociais. Diversos estudos têm mostrado que o alcoolismo é mais frequente nas famílias de alcoolitas do que na populaçäo em geral. Entretanto, além das influências genéticas, os fatores ambientais também säo responsáveis pela agregaçäo familiar observada, caracterizando, assim, uma herança multifatorial. A subdivisäo do alcoolismo nos tipos 1 e 2 tem permitido uma melhor compreensäo da doença do ponto de vista etiopatogênico e uma melhor abordagem da mesma. Apesar das diferenças metodológicas, a grande maioria dos estudos familiares sugere que os fatores säo muito importantes na determinaçäo do alcoolismo. Já foram identificados os seguintes fatores predisponentes ao alcoolismo: o alelo A1 do gene do receptor de dopammina DRD2, a reduçäo da atividade da MAO-B plaquetária, e a reduçäo da amplitude da onda P300 nos ERPs. Também evidenciou-se que uma anomalia da enzima transcetolase predispöe à Síndrome de Wernicke-Korsakoff. Além disto, foram identificados fatores protetores à doença, como a presença dos alelos ADH2*2 e ALDH2*2 dos genes das enzimas álcool desidrogenase, rspectivamente. Apesar da identificaçäo desses fatores associados ao alcoolismo, pouco ainda se sabe sobre o modo pelo qual eles interagem entre si e, portanto, muitos estudos ainda seräo necessários para um melhor esclarecimento do assunto

Los genes de los receptores a dopamina D2 y D4 distinguen la presencia clínica de tics en el trastorno obsesivo-compulsivo / Dopamine D2 and D4 receptor genes distinguish the clinica presence of tics in the obsessive-compulsive disorder

Se llevó a cabo un estudio de asociación alélica entre polimorfismos de los genes a los receptores a dopamina D2 (DRD2) y D4 (DRD4), en pacientes con trastornos obsesivos-compulsivo (TOC) con tics [TOC(+)] y sin tics [TOC(-)] motores o vocales. Se estudiaron 66 pacientes con TOC de acuerdo a los criterios del DSMIV (12 presentaron tics). Se tipificaron 54 sujetos controles. Los genotipos moleculares se determinaron por medio de la reacción en cadena de la polimerasa. Los pacientes con TOC(+) tuvieron mayor frecuencia del alelo Taql A2 (p=0.014) comparados con el grupo control, así como un exceso de individuos homocigotos A2A2 (p=0.001). La prevalancia de individuos con al menos una copia del alelo, así como la frecuencia total de alelos, del alelo mayor 7 del gene DRD4 fueron significativamente mayores en los pacientes TOC(+) comparados con los TOC(-) (91 por ciento vs 48 por ciento). El TOC(+) mostraron una frecuencia aumentada del alelo 7 del polimorfismo DRD4 que el TOC(-) (48 por ciento vs. 9 por ciento, p=0.018). Cuando ambos alelos se combinaban (al menos una copia del DRD2-A2 y una del DRD4-R7), los TOC(+) mostraban una mayor frecuencia de este haplotipo ((3.3 por ciento vs. 40 por ciento p= 0.016). El TOC con tics, podrían representar un subtipo genético/clínico de la enfermedad