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Biomedical subjects

D Di Bella

Publications and source records attributed to D Di Bella.

At least 19 recordsLinked to original sources

Combined family trio and case-control analysis of the COMT Val158Met polymorphism in European patients with anorexia nervosa.

The high activity Val158 (H) allele of the dopamine-metabolizing enzyme catechol-O-methyltransferase (COMT) was associated with anorexia nervosa (AN) in a recent family trio-based study of patients from Israel. In an attempt to replicate this finding, we performed a combined family trio and case-control study in an European population from seven centers in six different countries (Austria, Germany, Great Britain, Italy [Milan], Italy [Florence], Slovenia, and Spain), together contributing a total of 372 family trios, 684 controls and 266 cases. TDT analyses of high (H) and low (L) alleles in family trios showed that H allele and L allele were each transmitted 101 times (chi(2) = 0, ns). Allele-wise case-control analysis using separate samples simply combined from the centers was also not significant, with the frequencies of the H allele 50% in cases and same in controls. Stratified analysis of data from all centers gave an odds ratio of 0.98 (Cornfield 95% confidence limits 0.78-1.24). Analysis by genotype was likewise not significant (overall chi(2) = 0.42). Because we were not able to support the primary hypothesis that Val158Met is a risk factor for AN, we did not perform secondary analysis of minimum body mass index (mBMI), age at onset or illness subtype (restricting or binge purging anorexia). Overall we found no support for the hypothesis that the Val158 allele of COMT gene is associated with AN in our combined European sample.

Alleles↗

The 5-HT(2A) -1438G/A polymorphism in anorexia nervosa: a combined analysis of 316 trios from six European centres.

Several case-control association studies have raised the possibility that the A allele of a -1438 G/A polymorphism in the type 2A serotonin receptor (HTR2A) gene may be a risk factor for anorexia nervosa. However the absence of linkage and the existence of negative association studies raise the possibility of false positive findings, resulting from population stratification or lack of statistical power. To address this controversy we recruited a sample of 316 patients with anorexia nervosa from six European centres, and utilised a family-based transmission disequilibrium (TDT) approach to analyse the HTR2A-1438 G/A polymorphism. Age at onset and minimal BMI were also taken into consideration in order to detect clinical heterogeneity or a quantitative trait effect. The TDT approach showed that the A allele was transmitted 133 times and not transmitted 148 times (McNemar chi(2) = 0.29, df = 1, P = 0.59). Also, the haplotype-based haplotype relative risk method showed no evidence for association of the A allele, in samples from each centre (chi(2) < 2.15, df = 1, P > 0.14) and in the total sample (chi(2) = 0.55, df = 1; P = 0.46). Furthermore, we found no evidence for heterogeneity of the A allele frequency between samples (chi(2) = 2.54, df = 4, P = 0.64), either according to minimal-BMI (F1/242 = 2.14, P = 0.45) or age at onset (F1/224 = 2.39; P = 0.12). QTL-TDT analyses also showed no direct role of the A allele on these traits. We thus found no evidence for a significant role of the 5-HT(2A) gene in anorexia nervosa. Previous results may have been exposed to stratification bias (which we controlled by the TDT method) and/or the risk of type 1 error (from which we were less exposed because of the sample size).

Adolescent↗

Obsessive-Compulsive Disorder, 5-HTTLPR polymorphism and treatment response.

Recently, a role for a functional polymorphism within the promoter region of the serotonin transporter gene (5-HTTLPR) in conferring susceptibility to Obsessive Compulsive Disorder (OCD) has been suggested. The aim of this study was to test the hypothesis that allelic variation of the 5-HTTLPR could be associated with OCD susceptibility or influence the drug response in OCD. One hundred and eighty-one OCD patients were recruited; 92 patients underwent a standardized treatment with fluvoxamine. No significant differences in allele/genotype distribution of the 5-HTTLPR were found between 191 controls and OCD. No differences in fluvoxamine response in the three genotypes groups in OCD were found, considering Yale-Brown Obsessive Compulsive Scale (YBOCS) total scores. Nevertheless, a significant time per genotype interaction was found for the YBOCS subtotal compulsion scores. Considering patients without tic disorder co-diagnosis, a significant time per genotype interaction for both YBOCS total scores and compulsion scores was found.

Adult↗

An association study between 5-HTTLPR polymorphism, COMT polymorphism, and Tourette's syndrome.

Several lines of evidence suggest that a genetic component underlies Tourette's syndrome (TS). We investigated both the role of the insertion/deletion polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and that of the Val-158-Met substitution in the catechol-O-methyl-transferase (COMT) gene in conferring susceptibility to TS. Fifty-two TS patients were recruited and compared with a control group of 63 healthy subjects. Neither a genotypic nor an allelic association was found; subdividing TS patients according to clinical variables, such as a co-diagnosis of obsessive-compulsive disorder (OCD) and a positive family history for obsessive compulsive disorder or tics, also failed to reveal a significant association. The lack of significance for 5-HTTLPR and COMT polymorphisms in conferring liability to TS does not exclude a role of different functional polymorphisms in genes coding for serotonergic or dopaminergic structures in the etiology of TS. In fact, TS is a complex disorder and these genes most likely have only a minor genetic effect in its etiology.

Adult↗

Polymorphic MAO-A and 5-HT-transporter genes: analysis of interactions in panic disorder.

Recurrent panic attacks, anticipatory anxiety and phobic avoidance characterise panic disorder. The influence of genetic factors on liability to the disease has been the object of several linkage and association studies and appears to relate to an oligo- or polygenic rather than a monogenic mode of inheritance. Recently, an excess of high activity monoamine oxidase A (MAO-A) gene promoter alleles was found in female patients with panic disorder. An analysis of possible synergistic effects of the MAO-A gene promoter variant and the short serotonin transporter (5-HTT) gene promoter variant in panic disorder was performed in a German and an Italian sample (combined panic disorder n = 144, combined controls n = 175). There was no significant difference in odds ratios, suggesting that the observed increase of genetic liability by the long MAO-A gene promoter allele is not modified by the 5-HTT gene promoter polymorphism.

Adult↗

No interaction between serotonin transporter gene and dopamine receptor D4 gene in symptomatology of major psychoses.

Previously, we reported an association of the dopamine receptor D4 (DRD4) gene with delusional symptomatology of major psychoses. However, DRD4 variants accounted for only 2% of the phenotypic variance, indicating that contributions from other genes were probable. The serotonin transporter gene is a primary candidate in major psychoses, and a functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) has recently been reported to be associated with a number of psychopathological conditions. In the present study we investigated the original cohort of subjects to evaluate the 5-HTTLPR possible influence on the psychopathology of major psychoses in interaction with DRD4. Four hundred and sixty-one inpatients affected by major psychoses were assessed by the Operational Criteria Checklist for Psychotic Illness (OPCRIT) and were also typed for the 5-HTTLPR and DRD4 variants using polymerase chain reaction techniques. Mania, depression, delusion, and disorganization were the four symptomatologic factors used as phenotype definition. 5-HTTLPR variants did not significantly influence the previously reported association of DRD4 with delusional symptoms. No interaction was observed on the other symptom factors. The serotonin transporter gene does not, therefore, interact with DRD4 in determining the symptomatology of major psychoses.

Adolescent↗

Dopamine receptor D4 gene is not associated with major psychoses.

We previously reported an association between dopamine receptor D4 (DRD4) gene exon 1 variants and delusional disorder. The aim of this investigation was to study the DRD4 gene exon 1 and 3 variants in schizophrenia, delusional, bipolar, and unipolar disorders. We studied 651 inpatients affected by schizophrenia (n = 229), delusional (n = 86), bipolar (n = 210), and unipolar (n = 126) disorders (DSM III-R) and 471 healthy controls; these were typed for DRD4 variants at the first and third exon using polymerase chain reaction techniques. DRD4 variants were not associated with schizophrenic and delusional subjects even when possible confounders like gender and onset were considered. A marginal association between DRD4 exon 3 variants with unipolar (excess of DRD4*2/4, p = 0.004) and bipolar (excess of DRD4*2/4, p = 0.001) disorders was observed, both associations drop to insignificance when corrected for multiple testing. Our results exclude that coding variants of the DRD4 exon 1 and 3 may play a major role in conferring susceptibility to major psychoses; moreover, we could not replicate the association of DRD4 exon 1 variant with delusional disorder.

Adult↗

Dopamine receptor D2 and D4 genes, GABA(A) alpha-1 subunit genes and response to lithium prophylaxis in mood disorders.

Lithium is an effective prophylactic agent in mood disorders, and genetic factors are likely to modulate individual susceptibility to lithium treatment. The aim of this study is to investigate the influence of dopamine receptor D2 (DRD2), D4 exon 3 (DRD4), and gamma-aminobutyric acid type A (GABA(A)) receptor alpha-1 subunit (GABRA1) gene variants on the efficacy of lithium prophylaxis in mood disorders. Patients with mood disorders (N = 125: bipolar subtype, n = 100; major depressive disorder subtype, n = 25) were followed prospectively for an average of 53 months and were typed for DRD2 (Ser311/Cys311: n = 121, VNTR: n = 63), DRD4 (n = 125) and GABRA1 (n = 61) variants using polymerase chain reaction (PCR) techniques. DRD2, DRD4 and GABRA1 variants were not associated with response to lithium. A trend was observed toward a better outcome of DRD4* 2/4 subjects, but it was due to only two subjects. Consideration of possible stratification effects like gender, polarity, family history, age at onset and duration of lithium treatment did not reveal any association either. DRD2, DRD4 and GABRA1 variants therefore do not appear to be associated with the outcome of lithium prophylaxis in mood disorders.

Adult↗

No interaction of GABA(A) alpha-1 subunit and dopamine receptor D4 exon 3 genes in symptomatology of major psychoses.

Previously, we reported on an association of the dopamine receptor D4 (DRD4) gene with delusional symptomatology of major psychoses. However, despite the strength of the association, it only accounted for 2% of the variance, indicating that contributions from other genes were probable. In the present study, we investigated the original cohort of subjects to evaluate the gene for the gamma-aminobutyric acid type A (GABA(A)) receptor alpha-1 subunit (GABRA1). The possible association of GABRA1 with the psychopathology of major psychoses was tested both alone and in interaction with DRD4. Four hundred and sixty-one inpatients affected by major psychoses were assessed by the operational criteria checklist for psychotic illness (OPCRIT) and were also typed for the DRD4 and GABRA1 variants using PCR techniques. Mania, depression, delusion, and disorganization were the four symptomatologic factors used as phenotype definitions. GABRA1 variants were not associated with these symptomatologic factors, and consideration of possible stratification effects such as sex and psychiatric diagnosis also did not reveal any association. GABRA1 variants did not significantly influence the association of DRD4 with delusional symptoms. No interaction was observed on the other symptom factors. The GABA(A) alpha-1 subunit gene does not, therefore, interact with DRD4 in the symptomatology of major psychoses.

Adult↗

Serotonin transporter gene (5-HTTLPR) is not associated with depressive symptomatology in mood disorders.

Disturbances of the serotoninergic neutrotransmitter system have been implicated in the pathogenesis of mood disorders. A functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) has been recently reported to be associated with both unipolar and bipolar disorder. In this study, we investigated the possibility that the 5-HTTLPR might be associated with depressive symptomatology in a sample of mood disorder subjects. One hundred and thirty-two psychiatric inpatients affected by major depressive (n = 67) and bipolar (n = 65) disorder (DSM-IV) were assessed at admission by the Hamilton Depression Rating Scale (HAMD-21, divided into Core, Sleep, Activity, Psychic anxiety, Somatic anxiety and Delusion clusters) and were typed using PCR techniques. The only prior treatment permitted was low dose benzodiazepines (<5 mg diazepam or equivalent); no prior (<2 weeks) antidepressant or neuroleptic treatment was allowed. 5-HTTLPR variants were not associated with total depressive symptomatology as measured by HAMD. The short 5-HTTLPR variant was marginally associated with higher psychic anxiety scores (F = 7.11, d.f. = 1,262, P = 0.008). The association was stronger among bipolars and early onset subjects. 5-HTTLPR variants were not associated with the remaining symptom clusters. The upstream regulatory region of the serotonin transporter gene has not, therefore, a major influence on the depressive symptomatology in mood disorder subjects.

Alleles↗

Excess of high activity monoamine oxidase A gene promoter alleles in female patients with panic disorder.

A genetic contribution to the pathogenesis of panic disorder has been demonstrated by clinical genetic studies. Molecular genetic studies have focused on candidate genes suggested by the molecular mechanisms implied in the action of drugs utilized for therapy or in challenge tests. One class of drugs effective in the treatment of panic disorder is represented by monoamine oxidase A inhibitors. Therefore, the monoamine oxidase A gene on chromosome X is a prime candidate gene. In the present study we investigated a novel repeat polymorphism in the promoter of the monoamine oxidase A gene for association with panic disorder in two independent samples (German sample, n = 80; Italian sample, n = 129). Two alleles (3 and 4 repeats) were most common and constituted >97% of the observed alleles. Functional characterization in a luciferase assay demonstrated that the longer alleles (3a, 4 and 5) were more active than allele 3. Among females of both the German and the Italian samples of panic disorder patients (combined, n = 209) the longer alleles (3a, 4 and 5) were significantly more frequent than among females of the corresponding control samples (combined, n = 190, chi2 = 10.27, df = 1, P = 0.001). Together with the observation that inhibition of monoamine oxidase A is clinically effective in the treatment of panic disorder these findings suggest that increased monoamine oxidase A activity is a risk factor for panic disorder in female patients.

Alleles↗

Self-esteem in remitted patients with mood disorders is not associated with the dopamine receptor D4 and the serotonin transporter genes.

Disturbances of the dopaminergic and serotoninergic neurotransmitter systems have been implicated in the pathogenesis of depressive symptoms. Associations have been reported between markers of the two neurotransmitter systems and the presence of illness or severity of depressive episodes, but no attention has been focused on the periods of remission. The present report focuses on a possible association of self-esteem in remitted mood disorder patients with the functional polymorphism located in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) and the dopamine receptor D4 (DRD4). Inpatients (N=162) affected by bipolar (n=103) and unipolar (n=59) disorder (DSM III-R) were assessed by the Self-Esteem Scale (SES, Rosenberg, 1965) and were typed for DRD4 and 5-HTTLPR (n=58 subjects) variants at the third exon using polymerase chain reaction (PCR) techniques. Neither DRD4 nor 5-HTTLPR variants were associated with SES scores, and consideration of possible stratification effects such as sex and psychiatric diagnosis did not reveal any association either. The serotonin transporter and dopamine receptor D4 genes do not, therefore, influence self-esteem in remitted mood disorder subjects.

Adult↗

5HT2C CYS23/SER23 polymorphism is not associated with obsessive-compulsive disorder.

A great deal of evidence suggests that a genetic component underlies obsessive-compulsive disorder (OCD). The response to serotonergic medications and the worsening of obsessive symptoms after administration of serotonergic agonists indicate that serotonergic mechanisms are involved in OCD. We investigated the role of the Cys23Ser mutation of the 5HT2C receptor gene in the etiology of this disorder by performing an association study comparing a sample of 109 OCD patients with a sample of 107 healthy control subjects. No allelic or genotypic association of OCD with the 5HT2C receptor gene mutation was revealed in our data. We also extended the association analysis to a subsample of 39 OCD patients that had previously been submitted to a challenge test with clomipramine. In the subsample of OCD patients that received the challenge with clomipramine, no association between the 5HT2C receptor gene mutation and response to the challenge test was found. Our results exclude any specific role of the Cys23Ser mutation of 5HT2C receptor gene in the etiology of OCD: it seems probable that more complex genetic models are needed to explain the involvement of serotonergic elements in the etiology of this disorder.

Adult↗

Polymorphism within the promoter of the serotonin transporter gene and antidepressant efficacy of fluvoxamine.

Depression with psychotic features has been shown to respond to selective serotonin reuptake inhibitors (SSRIs). The serotonin transporter (5-HTT) is a prime target for SSRIs. A functional polymorphism within the promoter region of the 5-HTT gene, leading to different transcriptional efficiency, was recently reported. We tested the hypothesis that allelic variation of the 5-HTT promoter could be related to the antidepressant response to fluvoxamine and/or augmentation with pindolol (a serotonin autoreceptors antagonist) which has been suggested as an augmentation therapy for nonresponders. One hundred and two inpatients with major depression with psychotic features were randomly assigned to treatment with a fixed dose of fluvoxamine and either placebo or pindolol for 6 weeks. Depression severity was assessed once a week using the Hamilton Depression Rating Scale. Allelic variation in each subject was determined using a PCR-based method. Data were analyzed with a three-way repeated measures analysis of variance. Both homozygotes for the long variant (l/l) of the 5-HTT promoter and heterozygotes (l/s) showed a better response to fluvoxamine than homozygotes for the short variant (s/s). In the group treated with fluvoxamine plus pindolol all the genotypes acted like l/l treated with fluvoxamine alone. Fluvoxamine efficacy in delusional depression seems to be related to allelic variation within the promoter of the 5-HTT gene. Even though other factors may be implicated, genotyping at 5-HTT promoter may represent a promising tool to individualize the pharmacological treatment of depression.

Antidepressive Agents, Second-Generation↗

GABAA alpha-1 subunit gene not associated with depressive symptomatology in mood disorders.

Considerable evidence implicates the neurotransmitter gamma-aminobutyric acid (GABA) in the biochemical pathophysiology of mood disorders. In this study, we investigated the possibility that the gene for the gamma-aminobutyric acid type A (GABAA) receptor alpha-1 subunit (GABRA1) might be associated with depressive symptomatology in a sample of mood disorder subjects. Sixty-seven inpatients affected by unipolar (n = 37) and bipolar (n = 30) disorder (DSMIV) were assessed at admission by the Hamilton depression rating scale (HAMD) and were typed using polymerase chain reaction (PCR) techniques. GABRA1 variants were not associated with depressive symptomatology, and consideration of possible stratification effects such as sex, psychiatric diagnosis and illness severity did not reveal any association either. GABAA alpha-1 subunit gene is not, therefore, associated with depressive symptomatology in mood disorder subjects.

Adult↗

CO2-induced panic attacks: a twin study.

OBJECTIVE: The authors investigated the role of genetic factors in 35% CO2-induced panic attacks. METHOD: Ninety twins recruited from the general population were challenged with one-vital-capacity inhalations of 35% CO2-65% O2. Probandwise concordance rates were calculated and rates compared for monozygotic and for dizygotic twins. RESULTS: A significantly higher concordance was found for 35% CO2-induced panic attacks among monozygotic than dizygotic twins (55.6% versus 12.5%). CONCLUSIONS: These results suggest a relevant role of genetic factors in 35% CO2-induced panic attacks.

Adult↗