0000000000394586

AUTHOR

Peter Propping

A genome screen for genes predisposing to bipolar affective disorder detects a new susceptibility locus on 8q

Bipolar affective disorder (BPAD), also known as manic depressive illness, is a severe psychiatric disorder characterized by episodes of mania and depression. It has a lifetime prevalence of approximately 1% in all human populations. In order to identify chromosomal regions containing genes that play a role in determining susceptibility to this psychiatric condition, we have conducted a complete genome screen with 382 markers (average marker spacing of 9.3 cM) in a sample of 75 BPAD families which were recruited through an explicit ascertainment scheme. Pedigrees were of German, Israeli and Italian origin, respectively. Parametric and non-parametric linkage analysis was performed. The highe…

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Evaluation of linkage of bipolar affective disorder to chromosome 18 in a sample of 57 German families.

Previously reported linkage of bipolar affective disorder to DNA markers on chromosome 18 was reexamined in a large sample of German bipolar families. Twenty-three short tandem repeat markers were investigated in 57 families containing 103 individuals with bipolar I disorder (BPI), 26 with bipolar II disorder (BPII), nine with schizoaffective disorder of the bipolar type (SA/BP), and 38 individuals with recurrent unipolar depression (UPR). Evidence for linkage was tested with parametric and non-parametric methods under two definitions of the affected phenotype. Analysis of all 57 families revealed no robust evidence for linkage. Following previous reports we performed separate analyses afte…

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Mutationsanalyse des 5-HT1A-Rezeptor-Gens bei schizophrenen und affektiven Psychosen

Storungen im Serotoninstoffwechsel werden bei einer Vielzahl neuropsychiatrischer Erkrankungen (z. B. Angststorung, Depression, Schizophrenie, Alkoholismus, Migrane, Aggressives Verhalten, Suizidalitat, Tourette-Syndrom) beobachtet. Die Serotonin (5-Hydroxytryptamin, 5-HT) Rezeptoren konnen in mindestens drei Hauptgruppen unterteilt werden und zwar in 5-HTr, 5-HT2- und 5-HT3-Rezeptoren. Beim Menschen konnten bislang funf 5-HTrRezeptorsubtypen kloniert werden: der 5-HT1A, 5-HT1Dα, 5-HT1Dβ, 5-HT1E und der 5-HT1F Rezeptor (Ubersicht bei Shih et al. 1995). Der 5-HT1A ist der pharmakologisch am besten charakterisierte 5-HT1-Subtyp.

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Linkage studies of bipolar disorder in the region of the Darier's disease gene on chromosome 12q23-24.1.

We have recently described a family in which there is cosegregation of major affective disorder with Darier's disease and have mapped this autosomal dominant skin disorder to 12q23-q24.1. This has provided an interesting candidate region for genetic studies of bipolar disorder. We have studied the segregation of seven markers spanning the Darier's disease locus in 45 bipolar disorder pedigrees and found modest evidence in support of linkage under heterogeneity for 5 of these markers. Nonparametric analyses were suggestive of linkage with a marker at the gene encoding a secretory form of phospholipase A2. Our sample has relatively low power to detect linkage under heterogeneity and independe…

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A possible susceptibility locus for bipolar affective disorder in chromosomal region 10q25--q26.

In an attempt to identify susceptibility loci for bipolar affective disorder, we are currently conducting a systematic genome screen with highly polymorphic microsatellite markers at an average marker spacing of 10 cM in a series of 75 families, comprising 66 families from Germany, eight families from Israel, and one family from Italy. The families were ascertained through index cases with bipolar affective disorder. The distribution of diagnoses is as follows: 126 individuals with bipolar I disorder, 40 with bipolar II disorder, 14 with schizoaffective disorder of the bipolar type, 40 individuals with recurrent unipolar depression, 51 with a minor psychiatric diagnosis, and two individuals…

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Genetic relationship between five psychiatric disorders estimated from genome-wide SNPs

AM Vicente - Cross-Disorder Group of the Psychiatric Genomics Consortium Most psychiatric disorders are moderately to highly heritable. The degree to which genetic variation is unique to individual disorders or shared across disorders is unclear. To examine shared genetic etiology, we use genome-wide genotype data from the Psychiatric Genomics Consortium (PGC) for cases and controls in schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD). We apply univariate and bivariate methods for the estimation of genetic variation within and covariation between disorders. SNPs explained 17-29% of the variance in …

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Psychiatric genome-wide association study analyses implicate neuronal, immune and histone pathways

G.B. and S.N. acknowledge funding support for this work from the National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. P.H.L. is supported by US National Institute of Mental Health (NIMH) grant K99MH101367. Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an an…

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Systematic screening for mutations in the promoter and the coding region of the 5-HT1A gene.

In the present study we sought to identify genetic variation in the 5-HT{sub 1A} receptor gene which through alteration of protein function or level of expression might contribute to the genetic predisposition to neuropsychiatric diseases. Genomic DNA samples from 159 unrelated subjects (including 45 schizophrenic, 46 bipolar affective, and 43 patients with Tourette`s syndrome, as well as 25 healthy controls) were investigated by single-strand conformation analysis. Overlapping PCR (polymerase chain reaction) fragments covered the whole coding sequence as well as the 5{prime} untranslated region of the 5-HT{sub 1A} gene. The region upstream to the coding sequence we investigated contains a …

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Systematic screening for mutations in the human serotonin 1F receptor gene in patients with bipolar affective disorder and schizophrenia

Using single strand conformational analysis we screened the complete coding sequence of the serotonin 1F (5-HT{sub 1F}) receptor gene for the presence of DNA sequence variation in a sample of 137 unrelated individuals including 45 schizophrenic patients, 46 bipolar patients, as well as 46 healthy controls. We detected only three rare sequence variants which are characterized by single base pair substitutions, namely a silent T{r_arrow}A transversion in the third position of codon 261 (encoding isoleucine), a silent C{r_arrow}T transition in the third position of codon 176 (encoding histidine), and a C{r_arrow}T transition in position -78 upstream from the start codon. The lack of significan…

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Systematic screening for mutations in the human serotonin-2A (5-HT2A) receptor gene: Identification of two naturally occurring receptor variants and association analysis in schizophrenia

A statistically significant association between a silent mutation (102T/C) in the serotonin-2A (5-HT2A) receptor gene and schizophrenia has recently been reported in a sample of Japanese patients and healthy controls. This finding suggests that genetic predisposition to schizophrenia may be affected by a functional 5-HT2A receptor variant that is in linkage disequilibrium with 102T/C. In the present study, we have sought to identify genetic variation in the 5-HT2A receptor gene by screening genomic DNA samples from 91 unrelated subjects comprising 45 patients with schizophrenia and 46 healthy controls by using single-strand conformation analysis. We have identified four nucleotide sequence …

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