SERT and NET polymorphisms, temperament and antidepressant response.

BACKGROUND: The genetic variations in norepinephrine transporter (NET) and serotonin transporter (SERT) genes have been associated with personality traits, several psychiatric disorders and the efficacy of antidepressant treatment. AIMS: We investigated the separate effects and possible interactions between NET T-182C (rs2242446) and SERT 5-HTTLPR (rs4795541) polymorphisms on selective serotonin reuptake inhibitors (SSRI) treatment response and temperamental traits assessed by the Temperament and Character Inventory (TCI) in a clinical sample of subjects with major depressive disorder (MDD). METHODS: Our sample of 97 patients with major depression completed the 107-item TCI temperament questionnaire (version IX) at the initial assessment of the study and after 6 weeks of follow-up. All subjects received selective SSRI medications. Temperament dimension scores at baseline ( 1 ) and endpoint ( 2 ) during antidepressant treatment were analyzed between NET and SERT genotypes. RESULTS: SS-genotype of 5-HTTLPR was associated with higher baseline Persistence scores than SL- or LL-genotype. A corresponding but weaker association was found at endpoint. No differences were found between 5-HTTLPR genotypes and other temperament dimensions and 5-HTTLPR genotypes had no effect on treatment response. CONCLUSIONS: Our results suggest that the SS-genotype of 5-HTTLPR is associated with Persistence scores in patients with MDD. Higher Persistence could be viewed as a negative trait when recovering from stress and its association with short and "weaker" S-allele may be related to less efficient serotonin neurotransmission, possibly resulting in less effective coping strategies on a behavioral level.

Is 5-HTTLPR linked to the response of selective serotonin reuptake inhibitors in MDD?

The role of a functional polymorphism in the transcriptional control region of serotonin transporter gene (5-HTTLPR, SERTPR) has been studied intensively in major depression and in the response to selective serotonin inhibitors (SSRIs) in major depression. The findings have been contradictory, although majority of the studies indicate that the short allele is associated with poor response to SSRIs in major depression. In the present study, we evaluated the association of 5-HTTLPR with treatment response to SSRI medication in Finnish Caucasian MDD patients. A secondary purpose was to study the possible association of this particular polymorphism with major depressive disorder. The aim of the study was to replicate the previous findings in this area. Primary outcomes of the treatment were remission, defined by an exit score of seven or less, and response, defined by a reduction of at least 50% on the MADRS. We had also a control population of 375 healthy blood donors, as a secondary objective was to evaluate the possible association of this particular polymorphism with major depressive disorder. Twenty-nine of the 85 (34.1%) patients reached the remission and 58.8% achieved the predefined response criteria. The l/l genotype of 5-HTTLPR was presented in 51.7% of those patients who achieved remission vs. 25.0% in the non-remitters (P = 0.03). The result remained statistically significant after adjusting for age, gender, medication and MADRS points at the study entry. However, the small sample size limits the reliability of this result.

Mutation in the PYK2-binding domain of PITPNM3 causes autosomal dominant cone dystrophy (CORD5) in two Swedish families.

Autosomal dominant cone dystrophy (CORD5) (MIM 600977) is a rare disease predominantly affecting cone photoreceptors. Here we refine the CORD5 locus previously mapped to 17p13 from 27 to 14.3 cM and identified a missense mutation, Q626H in the phosphatidylinositol transfer (PIT) membrane-associated protein (PITPNM3) (MIM 608921) in two Swedish families. PITPNM3, known as a human homologue of the Drosophila retinal degeneration B (rdgB), lacks the N-terminal PIT domain needed for transport of phospholipids, renewal of photoreceptors membrane and providing the electroretinogram (ERG) response to light. In our study, the mutation causing CORD5 is located in the C-terminal region interacting with a member of nonreceptor protein tyrosine kinases, PYK2. Our finding on the first mutation in the human homologue of Drosophila rdgB indicates novel pathways and a potential important role of the PITPNM3 in mammalian phototransduction.

Serotonin transporter (5-HTTLPR) and norepinephrine transporter (NET) gene polymorphisms: susceptibility and treatment response of electroconvulsive therapy in treatment resistant depression.

Serotonin transporter (5-HTTLPR) and norepinephrine transporter (NET182C) polymorphisms are associated with susceptibility and treatment response in major depressive disorder (MDD). Thus, we examined association between these polymorphisms and susceptibility to treatment resistant depression, and treatment response in severe MDD patients treated with electroconvulsive therapy (ECT). In total, 119 Finnish patients with treatment resistant depression and 395 healthy volunteer blood donors were genotyped. Depression severity was assessed using the Montgomery-Åsberg Depression Scale (MADRS), with MADRS score change during ECT the treatment response indicator. Underrepresentation of the 5-HTTLPR l/l genotype in the NET TT subgroup was observed in patients compared with controls. There were no genotype or allele frequency differences between patients and control groups separately. Patients with combined 5-HTTLPR l/l and NET TT genotypes also had poorer treatment responses than other patients. No differences in ECT response were observed when the polymorphisms were examined separately. Our results suggest that a NET 182C and 5-HTTLPR polymorphism interaction is associated with susceptibility to treatment resistant depression and ECT treatment response in antidepressant resistant depression patients.

The CTLA4 region as a general autoimmunity factor: an extended pedigree provides evidence for synergy with the HLA locus in the etiology of type 1 diabetes mellitus, Hashimoto's thyroiditis and Graves' disease.

We have identified a large family in the northern part of Sweden with multiple cases of autoimmune diseases, namely type 1 diabetes (T1D), Graves' disease (GD) and Hashimoto's thyroiditis (HT). The family members affected by any of these diseases share a region of 2.4 Mb that comprises among others the CTLA4 gene. We determined that all affected members of the family shared the HLA susceptibility haplotype (DR4-DQA1*0301-DQB1*0302). Analysis of genetic interaction conditioning for HLA haplotype provided strong evidence that the critical region which includes the CTLA4 gene acts together with the HLA locus on the etiology of disease (lodscore 4.20 (theta=0.0). The study of this family allowed us to: (1) reinforce a number of reports on linkage and association of the CTLA4 region to T1D and AITD; (2) demonstrate that a single haplotypic variant in this region constitutes an etiological factor to disease susceptibility in T1D, GD and HT; (3) reveal a strong genetic interaction of the CTLA4 and HLA loci in the genetic architecture of autoimmune disease; (4) emphasise the value of large pedigrees drawn from isolated populations as tools to single out the effect of individual loci in the etiology of complex diseases.

Long leukocyte telomere length at diagnosis is a risk factor for dementia progression in idiopathic parkinsonism.

Telomere length (TL) is regarded as a marker of cellular aging due to the gradual shortening by each cell division, but is influenced by a number of factors including oxidative stress and inflammation. Parkinson's disease and atypical forms of parkinsonism occur mainly in the elderly, with oxidative stress and inflammation in afflicted cells. In this study the relationship between blood TL and prognosis of 168 patients with idiopathic parkinsonism (136 Parkinson's disease [PD], 17 Progressive Supranuclear Palsy [PSP], and 15 Multiple System Atrophy [MSA]) and 30 controls was investigated. TL and motor and cognitive performance were assessed at baseline (diagnosis) and repeatedly up to three to five years follow up. No difference in TL between controls and patients was shown at baseline, nor any significant difference in TL stability or attrition during follow up. Interestingly, a significant relationship between TL at diagnosis and cognitive phenotype at follow up in PD and PSP patients was found, with longer mean TL at diagnosis in patients that developed dementia within three years.

Homozygosity mapping of familial glioma in Northern Sweden.

About 5% of glioma cases are familial. Most glioma families are not ascribed to the well-known glioma predisposing syndromes. One segregation analysis has supported an autosomal recessive gene in glioma families, which could be studied by homozygosity mapping. The ancestors of seven glioma families from the northern region of Sweden were traced through genealogical databases. A common ancestor and inbreeding were traced to give support to an autosomal recessive gene. Homozygosity mapping was performed with a genome-wide scan of 811 markers with linkage calculations. The families were geographically mapped to see if familial glioma was more common in northern compared with southern Sweden. Three of the seven families were remotely related. Homozygosity mapping did not reveal any allele homozygous for all three families. However, there was a geographical clustering of glioma families in the northern region of Sweden. A non-parametric analysis showed an allele-sharing LOD score of 1.05 for marker D1S196 on chromosome 1q23. Genealogical studies linking glioma families might be a tool for linkage in a small set of families. This study did not support an autosomal recessive gene, implicating a low penetrant dominant gene as a possible explanation to the glioma family clustering.