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G Nestadt

Publications and source records attributed to G Nestadt.

At least 37 records · Page 2Linked to original sources
PubMed2000

Personality disorders and normal personality dimensions in obsessive-compulsive disorder.

BACKGROUND: Little is known about personality disorders and normal personality dimensions in relatives of patients with obsessive-compulsive disorder (OCD). AIMS: To determine whether specific personality characteristics are part of a familial spectrum of OCD. METHOD: Clinicians evaluated personality disorders in 72 OCD case and 72 control probands and 198 case and 207 control first-degree relatives. The selfcompleted Revised NEO Personality Inventory was used for assessment of normal personality dimensions. The prevalence of personality disorders and scores on normal personality dimensions were compared between case and control probands and between case and control relatives. RESULTS: Case probands and case relatives had a high prevalence of obsessive-compulsive personality disorder (OCPD) and high neuroticism scores. Neuroticism was associated with OCPD in case but not control relatives. CONCLUSIONS: Neuroticism and OCPD may share a common familial aetiology with OCD.

Adult↗
PubMed1999

Lack of linkage or association between schizophrenia and the polymorphic trinucleotide repeat within the KCNN3 gene on chromosome 1q21.

To determine the importance of a candidate gene KCNN3 (formerly named hSKCa3) in the susceptibility to schizophrenia, we have studied the genotypes of a (CAG)n polymorphism within this gene in the DNAs of the members of 54 multiplex families with this disease. Parametric and nonparametric linkage analysis did not provide evidence for linkage between KCNN3 (that we mapped to chromosome 1q21) and schizophrenia. Furthermore, we observed no difference in the distribution of the (CAG)n alleles between affected and normal individuals. These results do not support the hypothesis that larger KCNN3 alleles are preferentially associated with schizophrenia [Chandy et al. 1998 Mol Psychiatr 3:32-37] in individuals from multiply affected families.

Chromosome Mapping↗
PubMed1999

No evidence for linkage between schizophrenia and markers at chromosome 15q13-14.

Freedman et al. [1997: Proc Natl Acad Sci USA 94:587-592] reported linkage in nine multiplex schizophrenia families to markers on chromosome 15, using impaired neuronal inhibition to repeated auditory stimuli (P50), a neurophysiological deficit associated with schizophrenia, as the phenotype. The highest LOD score obtained (5.3 at theta = 0) was for marker D15S1360 mapped to chromosome 15q13-14, less than 120 kb from the alpha7-nicotinic receptor (CHRNA7) gene. The study also reported a small positive LOD score for D15S1360 when examined for linkage to the schizophrenia phenotype. Following these findings, we examined three polymorphic markers (D15S1360, L76630, and ACTC) on chromosome 15q13-14 near the CHRNA7 gene for linkage to schizophrenia, using 54 pedigrees from an independent study. Alleles for these three markers were genotyped and analyzed using parametric and nonparametric methods. No LOD score above 1.00 was obtained for any marker, and affected sib-pair analysis likewise showed no evidence for linkage. We conclude that in our families the region around the CHRNA7 locus does not contain a major locus for susceptibility to schizophrenia.

Chromosomes, Human, Pair 15↗
PubMed1998

Identification of sequence variants and analysis of the role of the catechol-O-methyl-transferase gene in schizophrenia susceptibility.

BACKGROUND: Deletions of 1.5-2 MB of chromosome 22q11 have been previously associated with schizophrenia. The deleted region includes proximally the region harboring genes involved in DiGeorge and velocardiofacial syndromes. Distally, it includes the gene for catechol-O-methyl-transferase (COMT), an enzyme that catalyzes the O-methylation of catecholamine neurotransmitters, including dopamine, and which therefore is considered a candidate gene for schizophrenia. METHODS: We address the issue of a direct involvement of the COMT gene in the development of schizophrenia by employing the first extensive mutational analysis of this gene in a sample of 157 schizophrenia patients and 129 healthy controls, using single-strand conformation polymorphism and chemical cleavage methodologies. RESULTS: No mutations were found, but several sequence variants were identified, including the genetic polymorphism that underlies the high/low activity of the enzyme (a Val158-->Met change, which results in the creation of an NlaIII restriction site in the low-activity allele). The distribution of the NlaIII genotypes among subsets of schizophrenia patients was analyzed. CONCLUSIONS: The results presented here argue against a major role of COMT in schizophrenia in general (although a minor effect could not be excluded) and represent a first step toward a more refined delineation of the phenotype/genotype relationship between 22q11 microdeletions and schizophrenia susceptibility.

Adult↗
PubMed1998

Schizophrenia susceptibility loci on chromosomes 13q32 and 8p21.

Schizophrenia is a common disorder characterized by psychotic symptoms; diagnostic criteria have been established. Family, twin and adoption studies suggest that both genetic and environmental factors influence susceptibility (heritability is approximately 71%; ref. 2), however, little is known about the aetiology of schizophrenia. Clinical and family studies suggest aetiological heterogeneity. Previously, we reported that regions on chromosomes 22, 3 and 8 may be associated with susceptibility to schizophrenia, and collaborations provided some support for regions on chromosomes 8 and 22 (refs 9-13). We present here a genome-wide scan for schizophrenia susceptibility loci (SSL) using 452 microsatellite markers on 54 multiplex pedigrees. Non-parametric linkage (NPL) analysis provided significant evidence for an SSL on chromosome 13q32 (NPL score=4.18; P=0.00002), and suggestive evidence for another SSL on chromosome 8p21-22 (NPL=3.64; P=0.0001). Parametric linkage analysis provided additional support for these SSL. Linkage evidence at chromosome 8 is weaker than that at chromosome 13, so it is more probable that chromosome 8 may be a false positive linkage. Additional putative SSL were noted on chromosomes 14q13 (NPL=2.57; P=0.005), 7q11 (NPL=2.50, P=0.007) and 22q11 (NPL=2.42, P=0.009). Verification of suggestive SSL on chromosomes 13q and 8p was attempted in a follow-up sample of 51 multiplex pedigrees. This analysis confirmed the SSL in 13q14-q33 (NPL=2.36, P=0.007) and supported the SSL in 8p22-p21 (NPL=1.95, P=0.023).

Adult↗
PubMed1998

Characterizing generalized anxiety: temporal and symptomatic thresholds.

We compared demographic and comorbidity profiles of subjects with varying levels of anxiety pathology to test if the clinical characteristics of generalized anxiety disorder (GAD) subjects differed from those of other subjects with generalized anxiety. Using Diagnostic Interview Schedule data from the 1993 follow-up study of the Baltimore cohort of the Epidemiologic Catchment Area Program, we divided subjects into the following five mutually exclusive symptom categories: a) DSM-III-R GAD; b) 6 months of worry or anxiety with six associated symptoms; c) 1 month of anxiety with or d) without six symptoms; and e) no anxiety. The first three groups were homogeneous with regard to demographic and comorbidity profiles, but their profiles differed from those of subjects with no anxiety or fewer than six symptoms. Thus, requiring six symptoms produced a group with a particular epidemiologic profile. Neither the nature of the subjects' worries nor the duration of symptoms influenced this profile. These results are discussed in terms of GAD's construct validity.

Adult↗
PubMed1998

Incidence of obsessive-compulsive disorder in adults.

This study addressed the incidence of obsessive-compulsive disorder (OCD) in adults in the general population. The Baltimore cohort of 3481 subjects, originally sampled during the 1981 multisite Epidemiologic Catchment Area Study, was traced. From 1993 to 1996, 1920 people were reinterviewed using the Diagnostic Interview Schedule. The incidence of DSM-III-R obsessive-compulsive disorder in adults was estimated at .55 per 1000 person-years. There was a relatively high rate of new cases in elderly women. It appeared that there were two peaks of onset of OCD over the life span, both of which occur later in female subjects. Subjects with adult incidence OCD often presented for psychiatric treatment, though they did not specify obsessive-compulsive symptoms as the reason. The difference in diagnostic criteria between DSM-III and DSM-III-R substantially influenced the threshold for new case identification.

Adolescent↗
PubMed1998

Association of obsessive-compulsive disorder and pathological gambling with Huntington's disease in an Italian pedigree: possible association with Huntington's disease mutation.

This paper describes a pedigree with Huntington's disease (HD), in which three cases of obsessive-compulsive disorder (OCD) and two cases of pathological gambling (PG) were identified. The mutation analysis of the HD gene was carried out in the examined individuals who were at risk for HD. In fact, OCD and PG only occurred in carriers of the HD expansion. The possible implications of this finding are discussed.

Adolescent↗
PubMed1996

A combined analysis of D22S278 marker alleles in affected sib-pairs: support for a susceptibility locus for schizophrenia at chromosome 22q12. Schizophrenia Collaborative Linkage Group (Chromosome 22).

Several groups have reported weak evidence for linkage between schizophrenia and genetic markers located on chromosome 22q using the lod score method of analysis. However these findings involved different genetic markers and methods of analysis, and so were not directly comparable. To resolve this issue we have performed a combined analysis of genotypic data from the marker D22S278 in multiply affected schizophrenic families derived from 11 independent research groups worldwide. This marker was chosen because it showed maximum evidence for linkage in three independent datasets (Vallada et al., Am J Med Genet 60:139-146, 1995; Polymeropoulos et al., Neuropsychiatr Genet 54:93-99, 1994; Lasseter et al., Am J Med Genet, 60:172-173, 1995. Using the affected sib-pair method as implemented by the program ESPA, the combined dataset showed 252 alleles shared compared with 188 alleles not share (chi-square 9.31, 1df, P = 0.001) where parental genotype data was completely known. When sib-pairs for whom parental data was assigned according to probability were included the number of alleles shared was 514.1 compared with 437.8 not shared (chi-square 6.12, 1df, P = 0.006). Similar results were obtained when a likelihood ratio method for sib-pair analysis was used. These results indicate that may be a susceptibility locus for schizophrenia at 22q12.

Alleles↗
PubMed1995

Schizophrenia susceptibility associated with interstitial deletions of chromosome 22q11.

We report the results of two studies examining the genetic overlap between schizophrenia and velocardiofacial syndrome. In study A, we characterize two interstitial deletions identified on chromosome 22q11 in a sample of schizophrenic patients. The size of the deletions was estimated to be between 1.5 and 2 megabases. In study B, we examine whether variations in deletion size are associated with the schizophrenic phenotype in velocardiofacial syndrome patients. Our results show that a region of the genome that has been previously implicated by genetic linkage analysis can harbor genetic lesions that increase the susceptibility to schizophrenia. Our findings should facilitate identification and cloning of the schizophrenia susceptibility gene(s) in this region and identification of more homogeneous subgroups of patients.

Abnormalities, Multiple↗
PubMed1995

Schizophrenia: a genome scan targets chromosomes 3p and 8p as potential sites of susceptibility genes.

Using a systematically ascertained sample of 57 families, each having 2 or more members with a consensus diagnosis of schizophrenia (DSM-III-R criteria), we have carried out linkage studies of 520 loci, covering approximately 70% of the genome for susceptibility loci for schizophrenia. A two-stage strategy based on lod score thresholds from simulation studies of our sample identified regions for further exploration. In each region, a dense map of highly informative dinucleotide repeat polymorphisms (heterozygosity greater than .70) was analyzed using dominant, recessive, and "affected only" models and nonparametric sib pair identity-by-descent methods. For one region, 8p22-p21, affected sib-pair analyses gave a P value = .0001, corresponding to a lod score approximately equal to 3.00. For 8p22-p21, the maximum two-point lod score occurred using the "affected only" recessive model (ZMAX = 2.35; theta M = theta F); allowing for a constant sex difference in recombination fractions found in reference pedigrees, ZMAX = 2.78 (theta M/theta F = 3). For a second region, 3p26-p24, the maximum two-point lod score was 2.34 ("affected only" dominant model), and the affected sib-pair P value was .01. These two regions are worthy of further exploration as potential sites of susceptibility genes for schizophrenia.

Biomarkers↗
PubMed1994

Sequential strategy to identify a susceptibility gene for schizophrenia: report of potential linkage on chromosome 22q12-q13.1: Part 1.

To identify genes responsible for the susceptibility for schizophrenia, and to test the hypothesis that schizophrenia is etiologically heterogeneous, we have studied 39 multiplex families from a systematic sample of schizophrenic patients. Using a complex autosomal dominant model, which considers only those with a diagnosis of schizophrenia or schizoaffective disorder as affected, a random search of the genome for detection of linkage was undertaken. Pairwise linkage analyses suggest a potential linkage (LRH = 34.7 or maximum lod score = 1.54) for one region (22q12-q13.1). Reanalyses, varying parameters in the dominant model, maximized the LRH at 660.7 (maximum lod score 2.82). This finding is of sufficient interest to warrant further investigation through collaborative studies.

Adult↗
PubMed1994

Follow-up of a report of a potential linkage for schizophrenia on chromosome 22q12-q13.1: Part 2.

A collaboration involving four groups of investigators (Johns Hopkins University/Massachusetts Institute of Technology; Medical College of Virginia/The Health Research Board, Dublin; Institute of Psychiatry, London/University of Wales, Cardiff; Centre National de la Recherche Scientifique, Paris) was organized to confirm results suggestive of a schizophrenia susceptibility locus on chromosome 22 identified by the JHU/MIT group after a random search of the genome. Diagnostic, laboratory, and analytical reliability exercises were conducted among the groups to ensure uniformity of procedures. Data from genotyping of 3 dinucleotide repeat polymorphisms (at the loci D22S268, IL2RB, D22S307) for a combined replication sample of 256 families, each having 2 or more affected individuals with DNA, were analysed using a complex autosomal dominant model. This study provided no evidence for linkage or heterogeneity for the region 22q12-q13 under this model. We conclude that if this region confers susceptibility to schizophrenia, it must be in only a small proportion of families. Collaborative efforts to obtain large samples must continue to play an important role in the genetic search for clues to complex psychiatric disorders such as schizophrenia.

Adult↗