| 21. |
- Melke, Jonas, 1971, et al.
(författare)
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A polymorphism in the serotonin receptor 3A (HTR3A) gene and its association with harm avoidance in women.
- 2003
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Ingår i: Archives of general psychiatry. - : American Medical Association (AMA). - 0003-990X. ; 60:10, s. 1017-23
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The brain neurotransmitter serotonin is known to affect various aspects of human behavior, including personality traits. Serotonin receptor type 3 is a ligand-gated channel encoded by 2 different subunit genes, HTR3A and HTR3B. A polymorphism (C178T) in the 5' region of the HTR3A gene has recently been identified and suggested to be of functional importance. OBJECTIVE: To elucidate the possible association between the C178T polymorphism in the HTR3A gene and personality traits in women. DESIGN: Two independent samples of 35- to 45-year-old Swedish women were recruited using the population register. Sample 1 (n = 195) was assessed via the Karolinska Scales of Personality and the Temperament and Character Inventory; sample 2 (n = 175) was assessed using the latter only. Both samples were genotyped with respect to the C178T polymorphism in the HTR3A gene. The A1596G polymorphism in the same gene was also investigated. RESULTS: A significant association between C178T genotype and the Temperament and Character Inventory factor harm avoidance was observed in sample 1 (corrected for multiple comparisons P =.04); this finding was subsequently replicated in sample 2 (P =.004) (pooled populations: P<.001). In the pooled sample, all harm avoidance subscales were found to be significantly associated with the C178T polymorphism: anticipatory worry (P =.001), fear of uncertainty (P<.001), shyness (P<.001), and fatigability and asthenia (P =.008). In addition, a significant association was found in sample 1 between the C178T polymorphism and the Karolinska Scales of Personality nonconformity factor (corrected P =.002), including the subscales of social desirability (P<.001), indirect aggression (P =.002), verbal aggression (P =.05), and irritability (P<.001). Participants homozygous for the less common T allele (<4%) differed from the remaining women by displaying lower ratings on harm avoidance and nonconformity. CONCLUSION: The C178T polymorphism in the HTR3A gene may affect the personality trait of harm avoidance in women.
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| 22. |
- Melke, Jonas, 1971, et al.
(författare)
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Abnormal melatonin synthesis in autism spectrum disorders.
- 2008
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 13:1, s. 90-98
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Tidskriftsartikel (refereegranskat)abstract
- Melatonin is produced in the dark by the pineal gland and is a key regulator of circadian and seasonal rhythms. A low melatonin level has been reported in individuals with autism spectrum disorders (ASD), but the underlying cause of this deficit was unknown. The ASMT gene, encoding the last enzyme of melatonin synthesis, is located on the pseudo-autosomal region 1 of the sex chromosomes, deleted in several individuals with ASD. In this study, we sequenced all ASMT exons and promoters in individuals with ASD (n=250) and compared the allelic frequencies with controls (n=255). Non-conservative variations of ASMT were identified, including a splicing mutation present in two families with ASD, but not in controls. Two polymorphisms located in the promoter (rs4446909 and rs5989681) were more frequent in ASD compared to controls (P=0.0006) and were associated with a dramatic decrease in ASMT transcripts in blood cell lines (P=2 x 10(-10)). Biochemical analyses performed on blood platelets and/or cultured cells revealed a highly significant decrease in ASMT activity (P=2 x 10(-12)) and melatonin level (P=3 x 10(-11)) in individuals with ASD. These results indicate that a low melatonin level, caused by a primary deficit in ASMT activity, is a risk factor for ASD. They also support ASMT as a susceptibility gene for ASD and highlight the crucial role of melatonin in human cognition and behavior.
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| 23. |
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| 24. |
- Melke, Jonas, 1971
(författare)
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Importance of serotonin-related candidate genes for human behaviour
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Family and twin studies have been consistent in demonstrating that genetic factors are involved in the etiology of most major psychiatric disorders, as well as in various normal personality traits. Mostly due to the efficacy of serotonin-acting drugs, such as selective serotonin reuptake inhibitors (SSRI) and tricyclic antidepressants (TCA), the neurotransmitter serotonin has been implicated in a variety of common psychiatric disorders, including depression, a spectrum of anxiety disorders, and premenstrual dysphoria; moreover, some studies have suggested that also personality is influenced by serotonin.The overall purpose of the studies presented in this thesis was to explore the possible influence of a variety of serotonin-related genes on a) normal personality traits, b) eating behavior, and c) two psychiatric disorders known to respond markedly to SSRIs, i.e., panic disorder and premenstrual dysphoria. Observations: 1) A previously suggested association between a promoter-region polymorphism (5-HTTLPR) in the serotonin transporter gene (SERT) and anxiety-related personality traits could be further substantiated. This relationship was observed in middle-aged women assessed with the personality questionnaire Karolinska Scales of Personality. 2) A recently identified polymorphism in the gene encoding the serotonin receptor 5-HT3 (HTR3A) was found to be associated with the personality trait harm avoidance, as assessed with the Temperament and Character Inventory. This association was observed in two independent samples of middle-aged women recruited from the normal population. 3) A functional effect of the 5-HTTLPR was supported by investigating the association between genotype and the expression of the serotonin transporter in human platelets. 4) An amino acid substitution (Cys23Ser) in the gene encoding the serotonin receptor 5-HT2C (HTR2C), was found to be associated with weight loss, and possibly also with anorexia nervosa, in teenage girls. 5) In association studies, polymorphisms in several serotonin-related genes were investigated in panic disorder patients and patients with premenstrual dysphoria. None of the investigated polymorphisms was found to be associated with these disorders.Conclusions: Our results lend support for an involvement of the SERT gene in the regulation of anxiety-related personality traits. The observed association between the HTR3A polymorphism and harm avoidance supports the notion that this personality trait is influenced by serotonin, and suggests that this influence may partly be mediated by 5-HT3 receptors. Our finding that the Cys23Ser polymorphism in the HTR2C could be associated with weight loss supports the suggested influence of this receptor subtype on eating behavior. The positive findings regarding personality traits contrast to the lack of association between serotonin-related genes and psychiatric disorders, such as panic disorder and premenstrual dysphoria. Tentatively, this discrepancy suggests that, for evolutionary reasons, it is less likely for a single common polymorphism to be of major importance for the etiology of psychiatric disorders, than for a normal trait that is not the subject of evolutionary pressure.
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| 25. |
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| 26. |
- Melke, Jonas, 1971, et al.
(författare)
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Serotonin transporter gene polymorphisms and platelet [3H] paroxetine binding in premenstrual dysphoria.
- 2003
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Ingår i: Psychoneuroendocrinology. - 0306-4530. ; 28:3, s. 446-58
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate if women with premenstrual dysphoria differ from controls with respect to the number of platelet serotonin transporters, and with respect to three polymorphisms in the gene coding for the serotonin transporter: a 44 base pair insertion/deletion in the promoter region, a variable number of tandem repeats in the second intron, and a single nucleotide polymorphism in the 3' untranslated region. Also, the possible relationship between the three polymorphisms and platelet serotonin transporter density was analyzed. The density of platelet [(3)H]paroxetine binding sites was significantly lower in women with premenstrual dysphoria than in controls, but patients and controls did not differ with respect to allele or genotype frequency for any of the three polymorphisms examined. A significant association between the number of platelet serotonin transporters and the promoter polymorphism was observed, subjects being homozygous for the short (deletion) variant having higher platelet serotonin transporter density than subjects carrying the long (insertion) allele. The results support the assumption that serotonin-related psychiatric disorders-such as premenstrual dysphoria-may be associated with a reduction in platelet [(3)H]paroxetine binding, but argue against the notion that this reduction is due to certain variants of the serotonin transporter gene being more common in patients than in controls.
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| 27. |
- Melke, Jonas, 1971, et al.
(författare)
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Serotonin transporter gene polymorphisms are associated with anxiety-related personality traits in women.
- 2001
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Ingår i: American journal of medical genetics. - 0148-7299. ; 105:5, s. 458-63
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have reported an association between anxiety-related personality traits and a promoter polymorphism in the human serotonin transporter (5-HTT) gene (5-HTT gene-linked polymorphic region, 5-HTTLPR). In the present study, a population of 251 subjects was assessed with the Karolinska Scales of Personality (KSP) and genotyped both for the 5-HTTLPR and for a variable number of tandem repeats polymorphism in the second intron of the same gene. The interpretation of previous studies has to some extent been confounded by the studied subjects differing with respect to ethnicity, sex, and age. To circumvent this problem, all included subjects were Caucasians, women, and born in the same year (1956). Associations were found between the 5-HTTLPR and four of the five anxiety-related KSP scales (psychic anxiety, muscular tension, psychasthenia, and lack of assertiveness), subjects being homozygous for the short allele displaying higher anxiety scores than those of the long/long or long/short genotype. In addition, an association was found between the intron 2 polymorphism and one anxiety-related personality trait (somatic anxiety).
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| 28. |
- Olsson, Marie, 1971, et al.
(författare)
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Angiotensin-related genes in patients with panic disorder.
- 2004
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Ingår i: American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics. - : Wiley. - 1552-4841. ; 127:1, s. 81-4
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Tidskriftsartikel (refereegranskat)abstract
- Enhanced respiratory variability and decreased heart rate variability have repeatedly been observed in patients with panic disorder. Prompted by the notion that angiotensin may be involved in the control of respiration, heart rate variability, and anxiety-like behavior, we investigated the putative association between polymorphisms in three angiotensin-related genes and panic disorder-angiotensinogen (AGT), angiotensin converting enzyme (ACE), and angiotensin II (ANG II) receptor type 1 (ATr1) in 72 patients with panic disorder and 504 controls. Allele and genotype distribution of the ATr1 A1166C allele and the AGT M235T did not differ between patients and controls. With respect to the ACE I/D polymorphism, the I allele was found to be more frequent in male (chi(2) = 8.042, df = 1, P = 0.005), but not female, panic disorder patients than in controls. The results of this investigation provide preliminary evidence for the suggestion that angiotensin-related genes may be associated with panic disorder in men.
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| 29. |
- Shahabi, H Niazi, et al.
(författare)
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Cytochrome P450 2E1 gene polymorphisms/haplotypes and Parkinson's disease in a Swedish population.
- 2009
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Ingår i: Journal of neural transmission (Vienna, Austria : 1996). - : Springer Science and Business Media LLC. - 1435-1463 .- 0300-9564. ; 116:5, s. 567-73
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Tidskriftsartikel (refereegranskat)abstract
- Cytochrome P450 2E1 (CYP2E1), which inter alia is located in dopamine containing neurons in the substantia nigra, has been hypothesized to be of importance for the pathophysiology of Parkinson's disease (PD), either by its production of reactive oxygen species (ROS) or by its capability to detoxify putative neurotoxins. Numerous polymorphisms in the coding and non-coding regions of the gene for this enzyme have been reported. Different variants may account for inter-individual differences in the activity of the enzyme or production of ROS. In this study, the CYP2E1 gene was examined in a control population (n = 272) and a population with PD (n = 347), using a tag-single nucleotide polymorphism (tSNP) approach founded on HapMap Data. Six tSNPs were used in the analysis and haplotype block data were obtained. In case of significance, the SNP was further examined regarding early/late age of disease onset and presence of relatives with PD. We found an association between allele and genotype frequencies of the C/G polymorphism at intron 7 (rs2070676) of this gene and PD (P value of 0.026 and 0.027, respectively). Furthermore, analysis of the rs2070676 polymorphism in subgroups of patients with age of disease onset higher than 50 years and those not having a relative with PD also demonstrated a significant difference with controls. This was seen in both genotype (corresponding to P value = 0.039 and 0.032) and allele (P = 0.027 and 0.017 respectively) frequency. As a representative of many polymorphisms or in possible linkage disequilibrium with other functional variants, it is possible that rs2070676 could influence the regulation of the enzyme. In conclusion, our results display an association between the rs2070676 polymorphism and PD. Additional investigations are needed to elucidate the importance of this polymorphism for the activity of CYP2E1 and PD susceptibility.
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| 30. |
- Westberg, Lars, 1973, et al.
(författare)
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Association between a dinucleotide repeat polymorphism of the estrogen receptor alpha gene and personality traits in women.
- 2003
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Ingår i: Molecular psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 8:1, s. 118-22
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Tidskriftsartikel (refereegranskat)abstract
- Estrogens are known to play a key role in the regulation of various aspects of behavior. In order to study the potential contribution of genetic variation in the estrogen receptor (ER) alpha to specific personality traits, we investigated a repeat polymorphism in the ER alpha gene in 172 42-year-old women who had been assessed using the Karolinska Scales of Personality (KSP). Based on the hypothesis that there is a relationship between the length of a repeat polymorphism and gene function,(1) the alleles were divided into two groups: short and long. In order to elucidate the possible influence of the ER alpha gene on the different aspects of personality measured by means of the KSP, the possible association between this gene and four different factors ('neuroticism', 'psychoticism', 'non-conformity', and 'extraversion') was analysed. 'Neuroticism', 'psychoticism', and 'non-conformity' all appeared to be associated with the ER alpha gene. After correction for multiple comparisons by means of permutation analysis, the associations with the factor 'non-conformity'--including the subscales 'indirect aggression' and 'irritability'--and the factor 'psychoticism'--including the subscale 'suspicion'--remained significant. The results suggest that the studied dinucleotide repeat polymorphism of the ER alpha gene may contribute to specific components of personality.
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