The molecular effect of a polymorphic microRNA binding site of Wolfram syndrome 1 gene in dogs.

BACKGROUND: Although the molecular function of wolframin remains unclear, the lack of this protein is known to cause stress in the endoplasmic reticulum. Some variants in the Wolfram Syndrome 1 gene (WFS1) were associated with various neuropsychiatric disorders in humans, such as aggressiveness, impulsivity and anxiety. RESULTS: Here we present an in silico study predicting a single nucleotide polymorphism (rs852850348) in the canine WFS1 gene which was verified by direct sequencing and was genotyped by a PCR-based technique. We found that the rs852850348 polymorphism is located in a putative microRNA (cfa-miR-8834a and cfa-miR-1838) binding site. Therefore, the molecular effect of allelic variants was studied in a luciferase reporter system that allowed assessing gene expression. We demonstrated that the variant reduced the activity of the reporter protein expression in an allele-specific manner. Additionally, we performed a behavioral experiment and investigated the association with this locus to different performance in this test. Association was found between food possessivity and the studied WFS1 gene polymorphism in the Border collie breed. CONCLUSIONS: Based on our findings, the rs852850348 locus might contribute to the genetic risk of possessivity behavior of dogs in at least one breed and might influence the regulation of wolframin expression.

DNA methylation patterns of behavior-related gene promoter regions dissect the gray wolf from domestic dog breeds.

A growing body of evidence highlights the relationship between epigenetics, especially DNA methylation, and population divergence as well as speciation. However, little is known about how general the phenomenon of epigenetics-wise separation of different populations is, or whether population assignment is, possible based on solely epigenetic marks. In the present study, we compared DNA methylation profiles between four different canine populations: three domestic dog breeds and their ancestor the gray wolf. Altogether, 79 CpG sites constituting the 65 so-called CpG units located in the promoter regions of genes affecting behavioral and temperamental traits (COMT, HTR1A, MAOA, OXTR, SLC6A4, TPH1, WFS1)-regions putatively targeted during domestication and breed selection. Methylation status of buccal cells was assessed using EpiTYPER technology. Significant inter-population methylation differences were found in 52.3% of all CpG units investigated. DNA methylation profile-based hierarchical cluster analysis indicated an unambiguous segregation of wolf from domestic dog. In addition, one of the three dog breeds (Golden Retriever) investigated also formed a separate, autonomous group. The findings support that population segregation is interrelated with shifts in DNA methylation patterns, at least in putative selection target regions, and also imply that epigenetic profiles could provide a sufficient basis for population assignment of individuals.

Rapid analysis of colipase gene variants by multicapillary electrophoresis.

Despite of the fact that the Human Genome Project was completed more than a decade ago, identification of the genetic background of polygenic diseases is still challenging. Several somewhat different approaches are available to investigate inheritable factors of complex phenotypes, all require, however efficient, high-throughput techniques for SNP genotyping. In this paper, we report a robust and reliable multiplex PCR-RFLP for genotype and haplotype analysis of six SNPs (rs41270082, rs3748051, rs142027015, rs3748048, rs73404011, and rs72925892) of the colipase (CLPS) gene. A multicapillary (12 capillaries) electrophoresis unit was used for high throughput and sensitive analysis of the digestion fragments. A Microsoft Excel-based spreadsheet was designed for the flexible visualization and evaluation of the electrophoretic separations, which is readily adaptable for any kind of electrophoresis application. Haplotype analysis of the two loci localized in close proximity of each other was carried out by molecular method, extended haplotypes including all five SNPs in the 5' upstream region were calculated. The techniques were applied in a case-control association study of type 2 diabetes mellitus. Although, single marker analysis did not reveal any significant association, it was observed that the rare GGCCG haplotype of the five 5' upstream region SNPs was about three times more frequent among patients compared to healthy control population. Our results demonstrated the applicability of multicapillary CGE in large-scale, high-throughput SNP analysis, and suggested that the CLPS gene polymorphisms might be considered as genetic risk factor for type 2 diabetes mellitus.

Rapid identification of human SNAP-25 transcript variants by a miniaturized capillary electrophoresis system.

The 25 kDa synaptosomal-associated protein (SNAP-25) is a crucial component of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex and plays an important role in neurotransmission in the central nervous system. SNAP-25 has two different splice variants, SNAP-25a and SNAP-25b, differing in nine amino acids that results in a slight functional alteration of the generated soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex. Two independent techniques, a PCR-miniaturized CE method and a real-time PCR based approach were elaborated for the specific and quantitative detection of the two SNAP-25 transcription variants. DNA-constructs coding for the two isoforms were used for optimization. Excellent specificity was observed with the use of our previously described highly sensitive miniaturized CE system in combination with quantitative PCR. The ratio of the two isoforms were reliably detected in a range of at least four orders of magnitude with a linear regression of R(2) = 0.987. Expression of the two isoforms was determined in human samples, where SNAP-25 was detected even in non-neural tissues, although at approximately a 100-fold lower level compared to the central nervous system. The relative amount of the SNAP-25b isoform was higher in the brain, whereas expression of SNAP-25a variant proved to be slightly higher in extra-neural cell types. The genomics approach in conjunction with the miniaturized CE system introduced in this paper is readily applicable for rapid alternative splice variant analysis.

[Neurocognitive endophenotypes in psychiatric genetics]. / Neurokognitív endofenotípusok a pszichiátriai genetikában.

Psychiatric genetics aims to map genetic factors of psychiatric disorders with complex inheritance. The most commonly used phenotype is the categorical variable of the presence or absence of a disease (case-control model). However, the biological background of various psychiatric disease categories often overlaps. Thus, the use of endophenotypes based on specific biological mechanisms seems to be a more efficient approach in genetic association studies. Results confirm that categorical variables as phenotypes are statistically not so sensitive in identification of a genetic association as well-chosen endophenotypes. Current literature advocates a growing significance of analyzing dimensional neurocognitive endophenotypes in genetic association studies, as well as in developing diagnostic category systems with biological backgrounds.

Glycogen synthase kinase 3 beta gene structural variants as possible risk factors of bipolar depression.

The glycogen synthase kinase 3B (GSK3B) is an important target protein of several antidepressants, such as lithium, a mood stabilizer. Recent studies associated structural variations of the GSK3B gene to bipolar disorder (BP), although replications were not conclusive. Here we present data on copy number variations (CNVs) of the GSK3B gene probing the 9th exon region in 846 individuals (414 controls, 172 patients with major depressive disorder (MDD) and 260 with BP). A significant accumulation (odds ratio: 5.5, P = 0.00051) of the amplified exon 9 region was found in patients (22 out of 432) compared to controls (4 of 414). Analyzing patient subgroups, GSK3B structural variants were found to be risk factors of BP particularly (P = 0.00001) with an odds ratio of 8.1 while no such effect was shown in the MDD group. The highest odds (19.7 ratio) for bipolar disorder was observed in females with the amplified exon 9 region. A more detailed analysis of the identified GSK3B CNV by a set of probes covering the GSK3B gene and the adjacent NR1I2 and C3orf15 genes showed that the amplified sequences contained 3' (downstream) segments of the GSK3B and NR1I2 genes but none of them involved the C3orf15 gene. Therefore, the copy number variation of the GSK3B gene could be described as a complex set of structural variants involving partial duplications and deletions, simultaneously. In summary, here we confirmed significant association of the GSK3B CNV and bipolar disorder pointing out that the copy number and extension of the CNV varies among individuals.

DRD4 and TH gene polymorphisms are associated with activity, impulsivity and inattention in Siberian Husky dogs.

Both dopamine receptor D4 (DRD4) exon 3 and tyrosine hydroxylase (TH) intron 4 repeat polymorphisms have been linked to activity and impulsivity in German Shepherd dogs (GSDs). However, the results in GSDs may not be generalisable to other breeds, as allelic frequencies vary markedly among breeds. We selected the Siberian Husky for further study, because it is highly divergent from most dog breeds, including the GSD. The study sample consisted of 145 racing Siberian Huskies from Europe and North America. We found that this breed possesses seven DRD4 length variants, two to five more variants than found in other breeds. Among them was the longest known allele, previously described only in wolves. Short alleles of the DRD4 and TH repeat polymorphisms were associated with higher levels of activity, impulsivity and inattention. Siberian Huskies possessing at least one short allele of the DRD4 polymorphism displayed greater activity in a behavioural test battery than did those with two long alleles. However, the behavioural test was brief and may not have registered variation in behaviour across time and situations. Owners also completed the Dog-Attention Deficit Hyperactivity Disorder Rating Scale (Dog-ADHD RS), a more general measure of activity and attention. Siberian Huskies from Europe with two short alleles of the TH polymorphism received higher ratings of inattention on the Dog-ADHD RS than did those with the long allele. Investigation of the joint effect of DRD4 and TH showed that dogs possessing long alleles at both sites were scored as less active-impulsive than were others. Our results are aligned with previous studies showing that DRD4 and TH polymorphisms are associated with activity-impulsivity related traits in dogs. However, the prevalence of variants of these genes differs across breeds, and the functional role of specific variants is unclear.

[Association between mood characteristics and polymorphisms of glial cell line-derived neurotrophic factor (GNDF) in patients with depression]. / A hangulati dimenziók és a glia-eredetü növekedési faktort kódoló gén polimorfizmusainak összefüggése depresszióval diagnosztizált mintán.

Glial cell line-derived neurotrophic factor (GNDF) plays an important role in the development and synaptic plasticity of dopaminergic neurons, thus it could be an important therapeutic factor in Parkinson's disease. Results from candidate gene studies of GDNF in psychiatric disorders are contradictory. Moreover, the possible association between GDNF polymorphisms and major- or bipolar depression has not been studied to date. Recently, our research group has published an association between two GDNF polymorphisms (rs3812047, rs3096140) and the individual variability of anxiety measured by the Hospital Anxiety and Depression Scale (HADS) on a non-clinical sample. In the present study we further analyzed this association on a sample with major- and bipolar depression: we used data from 183 MDD, 116 BP, and 1172 control subjects and tested effect of GDNF rs3812047 and rs3096140 polymorphisms on mood disorders. The case control design did not show significant differences in the genotype distribution of BP or MDD versus control patients. However, in the bipolar group subjects with rs3812047 A allele showed a significantly higher anxiety and depression mean score then subjects with G allele (p=0.043). This result supports our previous findings demonstrated on a non-clinical sample. Interestingly we found an opposite effect of the rs3812047 using data from MDD patients: subjects with the G allele had higher depression scores (p=0.012). An interaction effect of patient subgroups and genetic variants of the rs3812047 was observed for both HADS subscales (anxiety: p=0.029; depression: 0.004). In summary, we confirmed the previously published association between the rs3812047 A allele and mood characteristics on the bipolar sample, and an effect in the opposite direction was detected in the patient group with major depression.

Association of aggression with a novel microRNA binding site polymorphism in the wolframin gene.

Rare mutations in the WFS1 gene lead to Wolfram syndrome, a severe multisystem disorder with progressive neurodegeneration and diabetes mellitus causing life-threatening complications and premature death. Only a few association studies using small clinical samples tested the possible effects of common WFS1 gene variants on mood disorders and suicide, the non-clinical spectrum has not been studied yet. Self-report data on Aggression, Impulsiveness, Anxiety, and Depression were collected from a large (N = 801) non-psychiatric sample. Single nucleotide polymorphisms (SNPs) were selected to provide an adequate coverage of the entire WFS1 gene, as well as to include putative microRNA binding site polymorphisms. Molecular analysis of the assumed microRNA binding site variant was performed by an in vitro reporter-gene assay of the cloned 3' untranslated region with coexpression of miR-668. Among the 17 WFS1 SNPs, only the rs1046322, a putative microRNA (miR-668) binding site polymorphism showed significant association with psychological dimensions after correction for multiple testing: those with the homozygous form of the minor allele reported higher aggression on the Buss-Perry Aggression Questionnaire (P = 0.0005). Functional effect of the same SNP was also demonstrated in a luciferase reporter system: the minor A allele showed lower repression compared to the major G allele, if co-expressed with miR-668. To our knowledge, this is the first report describing a microRNA binding site polymorphism of the WFS1 gene and its association with human aggression based on a large, non-clinical sample.

Altered gene expression profiles in the hippocampus and prefrontal cortex of type 2 diabetic rats.

BACKGROUND: There has been an increasing body of epidemiologic and biochemical evidence implying the role of cerebral insulin resistance in Alzheimer-type dementia. For a better understanding of the insulin effect on the central nervous system, we performed microarray-based global gene expression profiling in the hippocampus, striatum and prefrontal cortex of streptozotocin-induced and spontaneously diabetic Goto-Kakizaki rats as model animals for type 1 and type 2 diabetes, respectively. RESULTS: Following pathway analysis and validation of gene lists by real-time polymerase chain reaction, 30 genes from the hippocampus, such as the inhibitory neuropeptide galanin, synuclein gamma and uncoupling protein 2, and 22 genes from the prefrontal cortex, e.g. galanin receptor 2, protein kinase C gamma and epsilon, ABCA1 (ATP-Binding Cassette A1), CD47 (Cluster of Differentiation 47) and the RET (Rearranged During Transfection) protooncogene, were found to exhibit altered expression levels in type 2 diabetic model animals in comparison to non-diabetic control animals. These gene lists proved to be partly overlapping and encompassed genes related to neurotransmission, lipid metabolism, neuronal development, insulin secretion, oxidative damage and DNA repair. On the other hand, no significant alterations were found in the transcriptomes of the corpus striatum in the same animals. Changes in the cerebral gene expression profiles seemed to be specific for the type 2 diabetic model, as no such alterations were found in streptozotocin-treated animals. CONCLUSIONS: According to our knowledge this is the first characterization of the whole-genome expression changes of specific brain regions in a diabetic model. Our findings shed light on the complex role of insulin signaling in fine-tuning brain functions, and provide further experimental evidence in support of the recently elaborated theory of type 3 diabetes.

Transcriptional modulation of monoaminergic neurotransmission genes by the histone deacetylase inhibitor trichostatin A in neuroblastoma cells.

Histone deacetylase inhibitors are promising anti-tumor agents partly due to their ability to disrupt the hypoxic signaling pathway in human malignancies. However, little is known about any effects of these drugs on the central nervous system. The aim of the present study was to analyze the effects of trichostatin A (TSA)--a broad-spectrum histone deacetylase inhibitor--on the transcriptional regulation of several genes involved in dopamine- and serotonergic neurotransmission. To this end, short-term parallel cultures of SK-NF-I neuroblastoma cells were treated with TSA either alone or in combination with hypoxia, and mRNA levels of dopamine receptor D3 (DRD3) and D4 (DRD4), dopamine transporter (DAT), dopamine hydroxylase (DBH), dopamine receptor regulating factor (DRRF), catechol-O-methyltransferase (COMT), serotonin receptor 1A (HTR1A), monoamino oxidase A (MAO-A), serotonin transporter (SLC6A4) and tryptophan hydroxylase 2 (TPH2) were determined by quantitative PCR. We found that TSA did not antagonize the hypoxia-induced activation of D3 and D4 dopamine receptor genes, implying that induction of these genes is not mediated directly by hypoxia inducible factor-1alpha. On the other hand, TSA dramatically upregulated the expression of DAT and SLC6A4 (45-fold and 15-fold, respectively), while transcript levels of MAO-A and COMT were significantly reduced (by 70% and by more than 90%, respectively). Induction of DAT protein expression was detected by western blotting. These results suggest that inhibition of histone deacetylases might help restore presynaptic monoamine pools via suppression of catecholamine breakdown and facilitation of monoamine reuptake in neurons.

[Genetic aspects of the Stroop test]. / A Stroop teszt genetikai vonatkozásai.

Impairment of executive control functions in depression is well documented, and performance on the Stroop Test is one of the most widely used markers to measure the decline. This tool provides reliable quantitative phenotype data that can be used efficiently in candidate gene studies investigating inherited components of executive control. Aim of the present review is to summarize research on genetic factors of Stroop performance. Interestingly, only a few such candidate gene studies have been carried out to date. Twin studies show a 30-60% heritability estimate for the Stroop test, suggesting a significant genetic component. A single genome-wide association study has been carried out on Stroop performance, and it did not show any significant association with any of the tested polymorphisms after correction for multiple testing. Candidate gene studies to date pointed to the polymorphisms of several neurotransmitter systems (dopamine, serotonin, acetylcholine) and to the role of the APOE ε4 allele. Surprisingly, little is known about the genetic role of neurothrophic factors and survival factors. In conclusion, further studies are needed for clarifying the genetic background of Stroop performance, characterizing attentional functions.

Additive effects of serotonergic and dopaminergic polymorphisms on trait impulsivity.

Twin studies suggest 45% heritability of trait impulsivity. Results from candidate gene studies to date are contradictory; impulsivity phenotypes were measured by different behavioral and questionnaire methods related either to the dopaminergic or to the serotonergic system. Here we report an association study of both dopaminergic (COMT rs4680, DRD4 48 bp VNTR, DRD2/ANKK1 rs1800497) and serotonergic (HTR1A rs6925, HTR1B rs13212041, SLC6A4 5-HTTLPR) gene polymorphisms and trait impulsivity assessed with the Barratt Impulsiveness Scale (BIS-11) in a sample of 687 Caucasian young adults. Results showed lower impulsivity in the presence of the DRD4 7-repeat (P = 0.006) and the HTR1B rs13212041 alleles (P = 0.003). These findings stayed significant after Bonferroni correction. A multivariate analysis using Bayesian networks confirmed independent effects of these two polymorphisms and provided a coherent characterization of the system of dependencies with respect to the impulsivity construct as well as its subscales. These results clearly suggest an additive effect of dopaminergic and serotonergic polymorphisms on trait impulsivity.

FOXN3 and GDNF Polymorphisms as Common Genetic Factors of Substance Use and Addictive Behaviors.

Epidemiological and phenomenological studies suggest shared underpinnings between multiple addictive behaviors. The present genetic association study was conducted as part of the Psychological and Genetic Factors of Addictions study (n = 3003) and aimed to investigate genetic overlaps between different substance use, addictive, and other compulsive behaviors. Association analyses targeted 32 single-nucleotide polymorphisms, potentially addictive substances (alcohol, tobacco, cannabis, and other drugs), and potentially addictive or compulsive behaviors (internet use, gaming, social networking site use, gambling, exercise, hair-pulling, and eating). Analyses revealed 29 nominally significant associations, from which, nine survived an FDRbl correction. Four associations were observed between FOXN3 rs759364 and potentially addictive behaviors: rs759364 showed an association with the frequency of alcohol consumption and mean scores of scales assessing internet addiction, gaming disorder, and exercise addiction. Significant associations were found between GDNF rs1549250, rs2973033, CNR1 rs806380, DRD2/ANKK1 rs1800497 variants, and the "lifetime other drugs" variable. These suggested that genetic factors may contribute similarly to specific substance use and addictive behaviors. Specifically, FOXN3 rs759364 and GDNF rs1549250 and rs2973033 may constitute genetic risk factors for multiple addictive behaviors. Due to limitations (e.g., convenience sampling, lack of structured scales for substance use), further studies are needed. Functional correlates and mechanisms underlying these relationships should also be investigated.

Haplotyping of putative microRNA-binding sites in the SNAP-25 gene.

Synaptosomal-associated protein 25 (SNAP-25) plays a crucial role in exocitosis. Single nucleotide polymorphisms (rs3746544 and rs1051312) in the 3' un-translated region of the SNAP-25 gene have been described to be in association with attention-deficit hyperactivity disorder. As the disease affects millions of children world-wide, understanding the genetic background of attention-deficit hyperactivity disorder is of crucial importance. Efficient and reliable PCR-RFLP protocols were elaborated for the genotyping of the rs3746544 and rs1051312 SNPs employing a high-throughput capillary electrophoresis method for fragment analysis. A novel real-time PCR-based technique was used applying sequence specific TaqMan probes to haplotype the two SNPs, and the G-C haplotype could not be detected in a large Caucasian population (N=1376). These findings have been confirmed by molecular biology tools as well as by the PHASE Bayesian computational approach. In silico analyses have suggested that the two SNPs might alter microRNA binding and thus have an effect on SNAP-25 production. We have demonstrated that this biological information can be revealed only by direct haplotype analysis emphasizing the importance of our novel molecular haplotye analysis protocol. Results of the study of the two SNPs might shed light on the association of SNAP-25 variants and pathological phenotypes at the molecular level.

[Effect of dopaminergic and serotonergic gene variants on cognitive performance]. / Dopaminerg és szerotonerg génvariánsok hatása a kognitív teljesítményre.

UNLABELLED: According to twin studies heritability of cognitive skills is substantial, however, little is known about the gene variants responsible for coding individual variability. Results of candidate gene studies implicate an important role of the dopaminergic system in coding individual differences in reaction time performance, and the possible role of the function of the serotonergic system has also emerged. GOALS: The aim of our study was to carry out association analyses between performance on the Stroop-task and selected gene polymorphisms of the dopaminergic and serotonergic system. RESULTS: In this study we examined 179 young adult's Stroop-performance measuring the attentional inhibition. The number of mistakes showed remarkable individual variability which can be related to the polymorphisms of the dopamine D4 receptor gene according to several previous studies. The short and long variations of the variable number tandem repeat polymorphism in the promoter region of the serotonin transporter gene was also studied based on the hypothesis of dopamine-serotonin balance. CONCLUSION: Our results demonstrate that the performance in the Stroop task is related to the genetic variants of the dopaminergic, as well as the serotonergic system.

Candidate gene studies of dopaminergic and serotonergic polymorphisms.

The most researched candidate genes of psychiatric genetic association studies are the components of the monoamine neurotransmitter systems, out of which serotonin and dopamine transmitter systems gained particular attention due to their major role in regulating emotional functions and cognitive processes. The paper reviews association studies focusing on the polymorphisms of receptors, transporters and enzymes that belong to these two transmitter systems. Numerous studies demonstrated significant associations between serotonergic and dopaminergic polymorphisms and diagnostic categories, personality traits and cognitive functions, however, results of monoamine gene variants and psychological properties are often contradictory. The contradictions can partially be explained with relatively small sample sizes of earlier studies, heterogeneity of methods across the studies and our expanding knowledge of the function of polymorphisms. On the whole, however, it can be declared that psychogenetic research plays an important role in the development of personalized pharmacotherapy.

[Genetic variability of the oxytocine receptor: an in silico study]. / Az oxitocinreceptor genetikai variabilitásának in silico elemzése.

UNLABELLED: There is an ongoing extensive study on the polymorphisms of the oxytocine receptor (OXTR) gene and their relation to certain psychological traits and psychiatric disorders, however the results are contradictory. One of the sources of inconsistency could originate from the fact that the OXTR gene contains more than 270 SNPs (single nucleotide polymorphisms) without clarified molecular effect. GOALS: The aim of this study was an in silico analysis of sequence variations between the human and dog OXTR gene. RESULTS: Comparative analysis of the human and the dog OXTR amino acid sequence revealed that the most robust difference between the two proteins is a five amino acid containing fragment which is present in the human but absent in the dog receptor. In silico addition of this sequence to the dog receptor resulted in a dramatic change in the conformation of the intracellular region. CONCLUSION: In silico comparative analysis of OXTR gene variants among species and individuals might serve as an important cue for predicting the functional effects of genetic variants.

[Clinical aspects of the link between diabetes and depression]. / A depresszió és a diabetes kapcsolatának klinikai vonatkozásai.

Diabetes mellitus and depression are public health concerns of the present and, as predicted, also the future. The observation that depression is seen more frequently in diabetic patients compared to the non-diabetic population has been proven by several recent studies. The co-occurrence carries further risks for the affected patients, as depression in diabetics may affect sufficient treatment of diabetes and enhance the development of diabetic complications. These may further worsen depressive symptoms causing a vicious cycle in these patients. In the present paper authors discuss in detail the theoretic and practical issues of the complex two directional relationships between diabetes and depression. Their goal is to draw attention to depression as co-morbidity of diabetes that may interfere with the optimization of diabetic patient's carbohydrate metabolism. If sufficient glycaemic control is not achieved using routine clinical methods depression should be evaluated as a probable cause. If needed, depression should be treated to improve the medical outcomes and quality of life of diabetic patients.

Analysis of a polymorphic microRNA target site in the purinergic receptor P2RX7 gene.

The recent discovery of post-transcriptional regulation by microRNAs (miRNAs) drew our attention to SNPs of putative miRNA target sites in candidate genes of depression-related psychiatric disorders. The P2RX7 (purinergic receptor P2X, ligand-gated ion channel, 7) gene has been suggested as a candidate for major depressive and bipolar disorder, because of repeated associations with the rs2230912 (Gln460Arg) polymorphism. As this polymorphism is located at the end of the coding region, we considered a possible linkage with SNP(s) in putative miRNA target sites of the 3' untranslated region. Based on our in silico search, the rs1653625 fulfilled this criterion. This SNP, however, is surrounded with polycytosine and polyadenine tracts, which hindered its analysis until now. In this study, we describe a readily applicable genotyping method for rs1653625 by applying a primer that introduces mismatched nucleotides to create a restriction enzyme cleavage site. The resulting allele-specific products with 19 base pair difference were separated by both traditional horizontal agarose gel electrophoresis and multicapillary gel electrophoresis. The developed genotyping method was applied in our depression-related association study.