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J Feingold

Publications and source records attributed to J Feingold.

At least 73 records · Page 4Linked to original sources
PubMed1998

Meta-analysis of DRD3 gene and schizophrenia: ethnic heterogeneity and significant association in Caucasians.

The involvement of dopamine in the etiology of schizophrenia is suggested by a number of neurobiological and pharmacological data, the dopamine D3 receptor (DRD3) being selectively expressed in brain regions which may be specifically involved in the risk for schizophrenia. The gene coding for DRD3 has thus been extensively analyzed. Since the initial report providing substantial evidence for an association of homozygosity of either allele of the gene coding for DRD3 (BalI polymorphisms) with schizophrenia, a flurry of replicating studies has appeared, which have been split into confirmations and nonreplications in North European Caucasian, Mediterranean, Asian, American, and African populations. The involvement of DRD3 polymorphisms thus remains questionable, particularly as no linkage studies have favored a nonrandom segregation of DRD3 alleles and schizophrenia. We performed a metaanalysis from 29 independent samples, from 24 different association studies so far published, allowing the examination of 2,619 schizophrenic patients and 2,517 controls. No significant differences of genotype counts were noted between patients and controls for the whole sample, considering frequency of any genotype. Starting from the high variability of the genotypes in different geographical areas, the impact of ethnic heterogeneity was taken into account. When the studies were reorganized in five groups according to geographical origin of samples, both homozygosity and 1-1 genotype revealed significant heterogeneity (P < 0.05). We specifically found an excess of homozygosity and 1-1 genotype in schizophrenic patients only in the African and Caucasian groups (P < 0.05). The present analysis suggests a small but significant effect of DRD3 in the susceptibility to schizophrenia, at least in Caucasians.

Deoxyribonucleases, Type II Site-Specific↗
PubMed1998

Lack of association between anorexia nervosa and D3 dopamine receptor gene.

BACKGROUND: Evidence from family and twin studies suggests a genetic contribution to the etiology of anorexia nervosa. Different genes could contribute to the vulnerability to anorexia nervosa, but dopamine could be more specifically implicated in anorexia nervosa because of pharmacologic, endocrine, and neurobiological specificities. The dopamine receptor D3 (DRD3) may be of additional interest, since it is specifically located in the limbic area, an area implicated in reward and reinforcement behavior. METHODS: We performed an association study between 39 patients with severe (requiring hospitalization and with young age at onset) anorexia nervosa (DSM-III-R), and 42 controls, with the Bal I polymorphism in exon I of the DRD3 gene. RESULTS: There was no significant difference between patients with anorexia nervosa and controls in allele frequencies or genotype count. The association was still negative between subgroups separated according to family history of anorexia nervosa or comorbid mood disorders. CONCLUSIONS: Despite the fact that the number of patients tested is small, there is good evidence that the Bal I DRD3 polymorphism does not play a major role in the genetic component of anorexia nervosa. It would be useful to test polymorphisms of the other genes coding for dopamine receptors.

Adolescent↗
PubMed1998

Association between the tryptophan hydroxylase gene and manic-depressive illness.

BACKGROUND: Genes encoding proteins involved in serotonergic metabolism are major candidates in association studies of mood disorders and suicidal behavior. This association study explores whether the tryptophan hydroxylase (TPH) gene, which codes for the rate-limiting enzyme of serotonin biosynthesis, is a susceptibility factor for manic-depressive illness, with or without a history of suicide attempts. METHODS: The TPH intron 7 A218C polymorphism was determined using a polymerase chain reaction-based method in DNA samples from 152 patients with bipolar disorder and 94 healthy control subjects. RESULTS: There was a significant association between TPH genotypes and manic-depressive illness. Among patients with bipolar disorder, no association was found between TPH alleles and suicidal behavior. CONCLUSIONS: This result suggests the involvement of the TPH gene in susceptibility to manic-depressive illness. This preliminary result requires confirmation in further groups of patients and controls.

Adult↗
PubMed1998

Hemoglobins in Togolese newborns: Hb S, Hb C, Hb Bart's, and alpha-globin gene status.

The gene frequency of the most important hemoglobin (Hb) abnormalities is reported in a population of 171 Togolese newborns. Hb phenotypes, hematological parameters, and the more frequently described alpha-gene deletions were analyzed. Structural abnormalities of beta-globin were observed in 35.7% of the children with a gene frequency of 0.105 for beta(S) and 0.091 for beta(C). The frequency of the different alpha-globin genotypes was alpha alpha/ = 0.71, -alpha/ = 0.28, and alpha alpha alpha/ = 0.01. All of the individuals homozygous for the -alpha genotypes, and most of the heterozygous individuals, carried Hb Bart's. Within the alpha alpha/alpha alpha and the -alpha/alpha alpha groups, several individuals with or without Hb Bart's were found; they did not differ from the others by their red blood cell (RBC) parameters but by their levels of fetal hemoglobin (Hb F). The African alpha2 polymorphism marker, characterized by the replacement of G by TCGGCCC at position 7238 (EMBL HSHBA4, 1993) and of T 7174 by G, was found in 21 newborns. The mean value of Hb F was calculated for each genotype, the mean (G)gamma percentage was 69.4 +/- 4.0%, and the gene frequency of the AgammaT marker was 0.10; this marker was linked to the normal beta-globin cluster.

Blood Cell Count↗
PubMed1998

The epsilon4 allele of the apolipoprotein E gene as a potential protective factor for exudative age-related macular degeneration.

PURPOSE: Apolipoprotein E (ApoE) is a polymorphic protein that plays a central part in plasma metabolism of lipids and in central nervous system lipid homeostasis. Our purpose was to evaluate the potential role of ApoE polymorphism in the occurrence of exudative age-related macular degeneration associated with drusen, which contain lipids. METHODS: We analyzed apolipoprotein E genotypes in 116 unrelated patients with exudative age-related macular degeneration in one eye and hard drusen (n = 39) or soft drusen (n = 77) in the other eye, and compared the results with those of age-matched and sex-matched control subjects (n = 168). Apolipoprotein E alleles were detected by a ploymerase chain reaction-based method. RESULTS: A lower frequency of the epsilon4 allele carriers was observed in the exudative age-related macular degeneration group compared with control subjects (12.1% vs 28.6%, respectively; P < .0009). The epsilon4 allele was less frequent in the age-related macular degeneration group compared with control subjects (0.073 vs 0.149, respectively; P < .006). This decreased frequency of the epsilon4 allele was mainly observed in the soft drusen subgroup compared with control subjects (0.045 vs 0.149, respectively; P < .0009). CONCLUSION: This lower relative frequency of the epsilon4 allele supports the hypothesis that the ApoE gene is a genetic protective factor identified in age-related macular degeneration.

Aged↗
PubMed1998

Multiple mutations in a specific gene in a small population.

Hereditary diseases have been reported with relatively high frequency in some small populations. Founder effect and genetic drift, associated or not with selective advantage of heterozygotes in case of recessive diseases, are the main explanations. Therefore, if we consider one population and one particular disease, only one deleterious allele should be observed. Determination of mutations has shown that in most cases the situation is more complex; more than one mutation is found among the patients. This finding can be explained by a multiple founder effect, with genetic drift and new mutations.

Founder Effect↗
PubMed1998

Recommendations for medical management of hereditary breast and ovarian cancer: the French National Ad Hoc Committee.

BACKGROUND AND PURPOSE: Almost 10% of breast and ovarian cancers are familial, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite uncertainty about the management of female gene carriers, consensus guidelines have been established to assist practitioners and consultees in making health care decisions. METHODOLOGY: The Ad Hoc Committee was composed of 14 experts appointed by the French National Institute for Health and Medical Research, all of whom attended eleven workshops at which more than 3500 articles were systematically analyzed. Five additional experts critically analysed the first version of the report. CRITERIA AND DECISION PROCESS: On a probability scale of the risk of developing breast or ovarian cancers, two thresholds were defined for use in determining whether an intervention would be worthwhile. The first is the threshold above which an intervention can be envisaged or recommended, and the second is the one below which an intervention can be ruled out; between the two, the decision has to be made on a case-by-case basis. SCREENING AND PREVENTIVE STRATEGIES ANALYZED: With respect to breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. With respect to ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: For each strategy the following points were addressed: the information to be given to the consultee, the procedure and the indications. In addition, the committee's opinion about BRCA1 and BRCA2 mutation screening is that population-based, or even large-scale, implementation are not justified. Although no scientific evidence is available, the committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and participation in clinical trials.

Breast Neoplasms↗
PubMed1998

Genotype-phenotype correlations in familial hypertrophic cardiomyopathy. A comparison between mutations in the cardiac protein-C and the beta-myosin heavy chain genes.

BACKGROUND: The gene involved in familial hypertrophic cardiomyopathy on chromosome 11 was recently identified as the cardiac myosin binding protein-C (MyBP-C) gene. The phenotype of two families associated with mutation in this gene is described here and compared to that of five families with mutations in the beta-myosin heavy chain gene. METHODS AND RESULTS: In adults (n = 33) bearing a splice acceptor site mutation in the MyBP-C gene, penetrance of familial hypertrophic cardiomyopathy was incomplete (69%) and ventricular hypertrophy mild. Among 37 clinical, electrocardiographic and echocardiographic parameters analysed, the only difference with the beta-MHC group (n = 35) was a shorter acceleration time of systolic flow in the pulmonary artery (P < 0.05). Sensitivity and specificity of diagnostic criteria were similar for the two genes. Cumulative survival rate for the splice acceptor site mutation (90% at 50 years old) was mid-way between that observed with a malignant (Arg403Leu: 42%) and a benign mutation (Arg403Trp: 100%) in the beta myosin heavy chain gene (P = 0.002). CONCLUSIONS: The detailed phenotype associated with a mutation in the MyBP-C gene was no different from that associated with mutations in the beta myosin heavy chain gene, except for prognosis which appeared more benign. These preliminary results suggest that there is no locus-specific genotype-phenotype correlation for the two genes analysed.

Adult↗
PubMed1998

A high rate (20%-30%) of parental consanguinity in cytochrome-oxidase deficiency.

By studying a large series of 157 patients, we found that complex I (33%), complex IV (28%), and complex I+IV (28%) deficiencies were the most common causes of respiratory chain (RC) defects in childhood. Truncal hypotonia (36%), antenatal (20%) and postnatal (31%) growth retardation, cardiomyopathy (24%), encephalopathy (20%), and liver failure (20%) were the main clinical features in our series. No correlation between the type of RC defect and the clinical presentation was noted, but complex I and complex I+IV deficiencies were significantly more frequent in cases of cardiomyopathy (P<.01) and hepatic failure (P<.05), respectively. The sex ratio (male/female) in our entire series was mostly balanced but was skewed toward males being affected with complex I deficiency (sex ratio R=1.68). Interestingly, a high rate of parental consanguinity was observed in complex IV (20%) and complex I+IV (28%) deficiencies. When parental consanguinity was related to geographic origin, an even higher rate of inbreeding was observed in North African families (76%, P<.01). This study gives strong support to the view that an autosomal recessive mode of inheritance is involved in most cases of mitochondrial disorders in childhood, a feature that is particularly relevant to genetic counseling for this devastating condition.

Abnormalities, Multiple↗
PubMed1998

Are cognitive changes the first symptoms of Huntington's disease? A study of gene carriers.

BACKGROUND: Huntington's disease is a neurodegenerative disorder due to an excessive number of CAG repeats in the IT15 gene on chromosome 4. The first symptoms are typically choreic movements or psychiatric disorders, whereas global cognitive decline generally becomes obvious later. This study was aimed at detecting early subtle cognitive deficits in asymptomatic gene carriers. METHODS: As part of the testing procedure for predictive diagnosis of Huntington's disease, 91 asymptomatic at risk candidates had a neuropsychological examination, evaluating global efficiency, attention, memory (Wechsler memory scale and California verbal learning test), and executive functions. RESULTS: The groups of carriers (n=42) and non-carriers (n=49) differed only on a few memory variables. When we considered the group of gene carriers as a whole, significant correlations emerged between the number of CAG repeats and (a) performance on several tests of executive functions, and (b) performance on the hard pairs associates of the Wechsler memory scale. Further analysis of performance on this memory subtest led to the division of the group of carriers into two subgroups, without any overlap. The performance of subjects without cognitive deficits (n=32) was similar to that of non-carriers on all tests. The subjects with cognitive deficits (n=10) differed from both carriers without cognitive deficits and non-carriers over a wide array of variables measuring executive functions and memory. Moreover, qualitative aspects of the performance of carriers with cognitive deficits in the California verbal learning test closely resembled those of patients diagnosed as having Huntington's disease. CONCLUSION: This suggests that these subjects already have Huntington's disease, despite a total lack of motor and psychiatric signs. An ongoing follow up study is testing the prediction that they will develop the full range of symptoms of the disease earlier than carriers without cognitive deficits.

Adolescent↗
PubMed1998

Genetic control of blood infection levels in human malaria: evidence for a complex genetic model.

There is now accumulating evidence for the involvement of genetic factors in the control of immune response against malaria. These arguments come from numerous animal models, from population studies showing associations of red blood cell genetic defects as well as HLA antigens with severe malaria, and from familial studies including a recent segregation analysis, which led to detection of a major gene effect predisposing to high infection levels. The heterogeneity and complexity of this genetic control is one of the main findings of these previous studies, and probably a major cause of the difficulty in developing an effective malaria vaccine. A segregation analysis of blood infection levels is performed here in 44 pedigrees living in the tropical rain forest of southern Cameroon and exposed to high vectorial transmission intensity. The results confirm the existence of complex genetic factors controlling blood infection levels in human malaria but are not consistent with the parent-offspring transmission of a single Mendelian gene. This study also shows the dramatic effect of age on infection levels and its interaction with a putative major gene suggesting that genetic related differences are much more important in children than in adults. Further genetic studies focused on children may help to identify the nature of the genetic factors involved in the expression of human malaria, by means of linkage analyses using both familial information and genetic markers.

Adolescent↗
PubMed1998

[INSERM-FNCLCC collective expert's report. Recommendations for management of women having a genetic risk of developing breast and/or ovarian cancer. National Federation of Centers of the Fight Against Cancer].

BACKGROUND: Almost 10% of breast and ovarian cancer are inherited, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite the uncertainty, consensus guidelines were defined to assist practitioners', and patients' decisions about the health care decisions to be made. METHODOLOGY: The Ad Hoc Committee consisted of 14 experts designated by the French National Institute for Health and Medical Research. They all attended eleven workshops at which a systematic analytical review of more than 3500 articles was carried out. Five additional experts critically analyzed the first version of the report. PROCESS: Two thresholds were defined on a probability scale giving the risk of developing breast or ovarian cancer, to serve as a means of deciding as whether an intervention is worthwhile. The first threshold is that above which an intervention can be envisaged or recommended; the second is that under which an intervention can be ruled out; between the two, the decision has to be made on a each by case basis. SCREENING AND PREVENTIVE STRATEGIES ANALYZED: About breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. About ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: With each strategy the following points were dealt with: the information to be delivered to the consultant, the procedure and the indications. The Committee's opinion about BRCA mutation screening is that population-based or even large scale implementation are not justified. The Committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and involvement in clinical trials.

Anticarcinogenic Agents↗
PubMed1998

An abnormal distribution of delta F508 genotypes in cystic fibrosis patient registries.

Delta F508 mutation of the CFTR gene is the most frequent deleterious allele involved in cystic fibrosis (CF). We have studied the distribution of the three genotypes, delta F508/delta F508, delta F508/x, x/x, in the American, Canadian and French data registries concerning CF; "x" represents the non-delta F508 mutations. In the three registries the observed distribution of the three genotypes differs from the expected one, calculated according to the Hardy and Weinberg equilibrium. Three factors could explain this discrepancy: Wahlund's effect, misinterpretation of the molecular diagnosis, or an ascertainment bias in relation with the severity of the disease. This last factor is the most likely.

Adolescent↗
PubMed1998

Prevalence of the C282Y mutation in Brittany: penetrance of genetic hemochromatosis?

Hemochromatosis (GH) is an inborn error of iron metabolism, characterized by progressive iron loading that, if untreated, causes high morbidity and death. The gene responsible for the disease (HFE), located 4.5 megabases telomeric to the HLA-A locus, encodes a protein homologous to class I MHC molecules. A main mutation, C282Y, has been identified within the gene. Although hemochromatosis is considered as the most frequent inherited disease in the populations of Northern European origin, its prevalence in Brittany had not been evaluated yet. In this issue we report the C282Y mutation frequency in a cohort of 1000 newborns from maternity hospitals of the four breton départements. The homozygote frequency was 5/1000 and heterozygote frequency was 12%; such high frequencies raise the question of the penetrance of the disease and the relevance of systematic genotypic screening for hemochromatosis.

Alleles↗
PubMed1998

[Determining the genetic component of common diseases].

The etiology of many human common diseases is complex and involves a combination of genetic and environmental factors. Genetic factors in most cases are common polymorphisms. Genetic epidemiology, which aim is to identify these factors addresses three sequential questions: Do diseases cluster in families. Is familial clustering related to genetic factors. How is genetic susceptibility inherited. In searching for disease genes, two strategies are possible: Association and/or linkage studies to candidate genes. Whole genome scans.

Cluster Analysis↗
PubMed1997

Apolipoprotein E gene polymorphism in early and late onset bipolar patients.

To explore the involvement of apolipoprotein E gene (APO E) in major depression, we studied the APO E gene polymorphism in a sample of 156 unrelated bipolar patients and 91 healthy volunteers. This population was stratified for age at onset of the affective disorder (onset before 18 years, after 45 years and between 18 and 45 years). Early onset bipolar patients with psychotic symptoms exhibited a significant increase of epsilon4 allele frequency (28.9%) compared to either other bipolar patients (13.1%, chi2 = 6.52, df = 1, P < 0.02) or controls (12.1%, chi2 = 7.01, df = 1, P < 0.01). The association between epsilon4 and early onset bipolar disorder (BPD) with psychotic symptoms suggests that APO E gene is a risk factor for a subgroup of BPD, or influences the phenotypic expression (i.e. psychotic symptoms or age at onset) of manic depressive illness.

Adult↗