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D Campion

Publications and source records attributed to D Campion.

At least 73 records · Page 4Linked to original sources

Mutations of the presenilin I gene in families with early-onset Alzheimer's disease.

We analyzed 12 families with autosomal dominant early-onset Alzheimer' s disease (EOAD)for mutations in the coding region of the presenilin I (PSNLI) gene corresponding to the AD3 locus on chromosome 14q24.3. A total of eight missense mutations at codons 82, 115, 139, 163, 231, 264, 392, and 410 including six novel mutations, were identified in eight families. Cosegregation of the mutations with EOAD was confirmed in three families, one including 36 affected individuals. This study underlines the great allelic heterogeneity and the large distribution of the mutations within the PSNLI coding region. Our results support the notion that PSNLI is the major gene involved in autosomal dominant EOAD.

Age of Onset↗

A large pedigree with early-onset Alzheimer's disease: clinical, neuropathologic, and genetic characterization.

We present clinical, neuropsychological, and neuropathologic data on a large pedigree including 34 subjects with early-onset progressive dementia. The mean (+/- SD) age at onset was 46 +/- 3.5 years and the mean age at death 52.6 +/- 5.7 years. Twelve patients were clinically diagnosed as having probable Alzheimer's disease (AD) according to the NINCDS-ADRDA criteria. Neuropsychological evaluation, performed at a moderate stage of the disease, was available in six subjects and showed a classic pattern of cognitive deficit. Myoclonus and extrapyramidal signs were common, and seizures were present in all affected subjects. There were neuropathologic changes typical of AD in two brains. A significant lod score of 5.48 was observed at a recombination fraction of theta = 0.0 with the genetic marker D14S43, thereby establishing that the responsible gene was located on chromosome 14q24.3. These results suggest that epilepsy could represent a particular feature in AD families linked to chromosome 14q.

Age of Onset↗

A rare allele of a microsatellite located in the tyrosine hydroxylase gene found in schizophrenic patients.

We investigated the frequency of a rare variant of a common microsatellite tetrarepeat allele in the tyrosine hydroxylase gene in 2 independent ethnic groups of schizophrenic patients and their matched controls. In a French population we found the rare variant allele in 5 of 94 (5%) unrelated chronic schizophrenic patients and in none of 145 unaffected controls, thus yielding a significant association (p < 0.01) between schizophrenia and the tyrosine hydroxylase gene. Similarly, in a replication study, we found the rare allele in 4 of 44 (9%) unrelated chronic schizophrenic patients and in none of 44 unaffected controls in a Tunisian population. Albeit the reason of this association is at the moment unknown, it is possible that this polymorphism in the tyrosine hydroxylase gene may be involved in the regulation of its activity.

Adult↗

[Phenotype of familial forms of early-onset Alzheimer's disease linked to chromosome 14. Clinical and neuropsychological characteristics of a large group].

We report the clinical features and neuropsychological data of chromosome-14 linked early-onset Alzheimer's disease in a large family (FAD-RO1). Information available in the literature from eight additional chromosome 14-linked Alzheimer's disease kindreds was compared with the data obtained from six kindreds with amyloid precursor protein gene mutations (APP). In the chromosome 14-linked families the disease has an earlier onset and a shorter duration than in families with APP mutations, with an age at death lower than sixty years of age. Seizures, myoclonus and extra pyramidal signs were frequently present in the cases of FAD-RO1 as in six chromosome 14-linked kindreds, but these features were absent in two other ones. The high frequency of seizures (> 80%) in FAD-RO1 and two other chromosome 14-linked kindreds is remarkable. Seizures and myoclonus were encountered at a lower prevalence in APP kindreds. This review suggests that some clinical features are more prevalent in chromosome 14-linked than in APP kindreds but a phenotypic heterogeneity does exist within and between families. The profile of deterioration of the neuropsychological performances, as illustrated by the FAD-RO1 members, shows that chromosome 14-linked kindreds do not demonstrate a specific expression in comparison to APP kindreds. Memory was first impaired. Deficits in visuo-spatial and visuopractic abilities were then noted. Finally the verbal performance deteriorated.

Adult↗

Genetic study of dopamine D1, D2, and D4 receptors in schizophrenia.

The goal of this study was to define precisely the involvement of the dopamine D1, D2, and D4 receptor genes in the etiology of schizophrenia. A linkage analysis using the lod score method was performed in 37 families originating from France (n = 14) and from the Island of La Réunion in the Indian Ocean (n = 23). No evidence of linkage between schizophrenia and genetic markers located at these loci was found. A simulation study was carried out to gauge the significance of these results. The conclusions of a nonparametric linkage test (i.e., the affected pedigree member method) were equally negative. For each genetic marker, an allelic association with the disease was also sought: 80 unrelated patients and 80 healthy control subjects were tested, and no significant association was found. These results, which are in agreement with those obtained by other groups, do not support the involvement of the dopamine D1, D2, and D4 receptor genes in the pathogenesis of schizophrenia.

Female↗

Pseudoautosomal region in schizophrenia: linkage analysis of seven loci by sib-pair and lod-score methods.

In a previous study, we reported a nonrandom segregation between schizophrenia and the pseudoautosomal locus DXYS14 in a sample of 33 sibships. That study has been extended by the addition of 16 new sibships from 16 different families. Data from six other loci of the pseudoautosomal region and of the immediately adjacent part of the X specific region have also been analyzed. Two methods of linkage analysis were used: the affected sibling pair (ASP) method and the lod-score method. Lod-score analyses were performed on the basis of three different models--A, B, and C--all shown to be consistent with the epidemiological data on schizophrenia. No clear evidence for linkage was obtained with any of these models. However, whatever the genetic model and the disease classification, maximum lod scores were positive with most of the markers, with the highest scores generally being obtained for the DXYS14 locus. When the ASP method was used, the earlier finding of nonrandom segregation between schizophrenia and the DXYS14 locus was still supported in this larger data set, at an increased level of statistical significance. Findings of ASP analyses were not significant for the other loci. Thus, findings obtained from analyses using the ASP method, but not the lod-score method, were consistent with the pseudoautosomal hypothesis for schizophrenia.

Family↗

No major role for the dopamine D2 receptor Ser-->Cys311 mutation in schizophrenia.

A new structural polymorphism (Ser311/Cys311) in the dopamine D2 receptor (DRD2) gene has recently been reported to be associated with schizophrenia, particularly in patients with a positive family history of schizophrenia (Arinimi et al., 1994). However these findings remain controversial (Asherson et al., 1994; Nanko et al., 1994; Nöthen et al., 1994; Shaikh et al., 1994). Thus we investigated the role of the Cys311 mutation in schizophrenia using both association and family studies. First, we screened for the Cys311 mutation in 113 unrelated Caucasian schizophrenics (mean age 42 +/- 0.6; 34 females and 79 males) including 25 familial cases, and 184 unrelated controls (mean age 49 +/- 0.5, 74 females and 110 males) free of any psychiatric disorders. Diagnoses were ascertained according to DSM-III criteria (Campion et al., 1994). All patients and controls were native to the area of Rouen.

Alleles↗

Failure to find evidence for linkage or association between the dopamine D3 receptor gene and schizophrenia.

OBJECTIVE: This study was performed to assess the possible involvement of the dopamine D3 receptor gene (DRD3) in the etiology of schizophrenia. The authors' approach included a population study and a family study using both parametric (lod score) and nonparametric (affected pedigree member) methods of linkage analysis. METHOD: Two different DNA markers were studied at the DRD3 locus. The family study included 35 multiplex families of schizophrenic subjects for the linkage analyses. The population study involved 50 unrelated schizophrenic subjects and 50 normal comparison subjects from the same ethnic and geographic origin. RESULTS: Whichever clinical classification was used to define the pathological phenotype (schizophrenia or schizophrenia spectrum), the results of the lod score and affected pedigree member studies did not provide any evidence of linkage of the DRD3 gene to the illness. The negative results of the association study reinforce these results. CONCLUSIONS: The hypothesis that the DRD3 gene has a predisposing role in schizophrenia was not supported by these population and family studies. However, the possibility that this gene has a role in the etiology of the disease cannot be definitely excluded because of the intrinsic limitations of the methods of analysis and the number of subjects studied.

Alleles↗

Is a single mutation at the same locus responsible for all affected cases in a large Alzheimer pedigree (FAD4)?

Analysis of marker segregation in the large Alzheimer pedigree, FAD4, leads to the conclusion, with a type I error of 5%, of linkage heterogeneity between two branches of the pedigree: the disease cosegregates with chromosome 21 markers flanking the APP area in one branch and not in the other one. Thus, we conclude that a single mutation in the chromosome 21 region surrounding APP cannot be responsible for all the affected cases in this pedigree.

Alleles↗

SPEM impairment in drug-naive schizophrenic patients: evidence for a trait marker.

Smooth-pursuit eye movements (SPEM) were assessed in healthy subjects and in drug-naive, chronic, and residual schizophrenic patients. SPEM gain was found to be decreased in all the schizophrenic patients who also exhibited a significant increase in the rate of saccades. The frequency of square-wave jerks was the same in schizophrenic patients and normal controls, suggesting that the primary abnormality in schizophrenic patients was a low gain rather than a defect of the saccadic system. Patients were retested 1 month later, and stability of gain was high even in formerly drug-naive subjects who had been treated for 1 month with neuroleptic drugs. Altogether these results confirm the conclusions of most previous studies, extend them to drug-naive schizophrenic patients, and favor the hypothesis that SPEM impairment is a trait marker in schizophrenia.

Adult↗

Failure to replicate linkage between chromosome 5q11-q13 markers and schizophrenia in 28 families.

Sherrington et al. (1988) reported linkage between markers located on the 5q11-q13 region of chromosome 5 and schizophrenia in five Icelandic and two British families. To date, however, all attempts to replicate the initial finding have failed. Using three markers of chromosome 5, we have studied 28 additional French pedigrees. When our data were analyzed both with parametric (i.e., lod scores) and nonparametric methods, we found no evidence of linkage. Thus, we were unable to replicate the earlier report by Sherrington et al.

Chromosomes, Human, Pair 5↗

Relationship of HLA to schizophrenia not supported in multiplex families.

The role of the human histocompatibility complex (HLA) in the pathogenesis of schizophrenia has been suggested in previous reports. We conducted a genetic study in 33 new families. Our linkage analysis, which used the affected sib-pair method, did not provide evidence for nonrandom assortment. Moreover, the results of an association study using the "haplotype relative risk" method failed to confirm the positive association between HLA A9 and schizophrenia. Taken together, our data did not support any relationship of HLA type to schizophrenia.

Genetic Linkage↗

Clinical subtypes and age at onset in schizophrenic siblings.

This study examines the concordance of clinical subtypes and age at onset of schizophrenia in 42 sibships of multiply affected schizophrenic patients. Subtypes were defined by four major diagnostic systems (DSM-III, DSM-III-R, ICD-10, and Tsuang-Winokur criteria) and rated both for the first hospitalization and long-term diagnosis. When a sibship method was used, no concordance for subtypes was found in siblings. Age at onset, analyzed as a continuous variable with the intraclass correlation method, was found to be correlated in siblings. This finding suggest that the search for continuous traits distributed in families of schizophrenic patients might constitute an alternative to discrete category-based family studies.

Age Factors↗