Biomedical subjects

Michael Ritsner

Publications and source records attributed to Michael Ritsner.

At least 19 recordsLinked to original sources

PubMed2006

Differences in blood pregnenolone and dehydroepiandrosterone levels between schizophrenia patients and healthy subjects.

BACKGROUND AND OBJECTIVE: Contradictory and confusing reports on serum dehydroepiandrosterone (DHEA) levels in schizophrenia led us to compare the serum concentration of its precursor, pregnenolone (PREG), between medicated schizophrenia patients and healthy subjects. The neurosteroid levels were monitored for two months and the relationship of these neurosteroids with schizophrenic symptomatology, emotional distress, and anxiety was examined. METHOD: We determined blood levels of PREG, and DHEA in 15 schizophrenia patients and 12 healthy controls at four time points: at the start of the study, after 2, 4 and 8 weeks. Analysis of covariance and canonical correlations across four time points were applied. RESULTS: Controlling for age, serum concentrations of PREG were lower, while the DHEA level and the molar ratio values of DHEA/PREG were higher in schizophrenia patients compared to healthy controls. Both levels of PREG and DHEA and their molar ratio did not change significantly during the study's period either among schizophrenia patients or healthy controls. The blood levels of PREG appear to be associated with trait-anxiety scores in the schizophrenia patients, while associations of clinical symptoms with two neurosteroids did not reach a significant level when the confounding effect of emotional distress, and anxiety scores was controlled. CONCLUSION: Low serum pregnenolone concentrations in schizophrenia appear to be associated with trait-anxiety scores independent of symptoms. Further research into the role of pregnenolone in schizophrenia is warranted.

Adult↗

PubMed2006

State and trait related predictors of serum cortisol to DHEA(S) molar ratios and hormone concentrations in schizophrenia patients.

OBJECTIVE: In previous studies we have demonstrated high serum molar ratios of cortisol to dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) [together abbreviated DHEA(S)], and the value of both cortisol/DHEA(S) molar ratios for prediction of responsivity to antipsychotic treatment in schizophrenia patients. The present study aimed to examine the contribution of anxiety, and severity of symptoms to the prediction of serum cortisol, DHEA(S) levels and two molar ratios across three examinations. METHOD: Serum concentrations of cortisol and DHEA(S)were examined in 43 schizophrenia inpatients and in 20 age matched healthy controls at baseline, and after 2 and 4 weeks. The Positive and Negative Symptom Scale and the State-Trait Anxiety Inventory scores were used as independent variables for multiple regression analysis. RESULTS: Despite clinical improvement during the study period cortisol/DHEA(S) molar ratios were found persistently elevated as compared to healthy controls. Multiple regression analysis revealed that across three examinations cortisol/DHEA(S) molar ratios negatively associated with trait-anxiety (partial R(2)=7-14%) rather than with negative symptoms (partial R(2)=3-6%). Age and age of onset account for 12.7% for variability of cortisol/DHEAS ratio. Serum cortisol concentrations are predicted by trait and state-anxiety, activation symptoms and daily doses of antipsychotics. A small portion of variability in serum DHEA levels (R(2)=9%) is associated with symptom severity, while DHEAS levels were predicted by age at examination and age of onset. CONCLUSION: Elevated serum cortisol/DHEA(S) molar ratios were attributed to trait-anxiety and age rather than to clinical symptoms. The findings may indicate persistent dysfunction of the hypothalamic-pituitary-adrenal axis that is independent of the patients' clinical state.

Adult↗

PubMed2006

Determinants of changes in perceived quality of life in the course of schizophrenia.

This study aimed to identify factors that influence changes in satisfaction with quality of life (QOL) of schizophrenia patients. Baseline and follow up data for 148 schizophrenia patients were obtained at hospital admission and 16 months later. Relationships between changes over time in the general QOL index, and various factors were investigated using factor, multiple regression, and partial correlation analyses. Findings indicate that baseline levels of activation symptoms, emotional distress, task oriented coping, self-esteem and friend support together explain 41% of the variability in the general QOL index 16 months later. Changes in the general QOL of schizophrenia patients over time is associated with anergia, and paranoid symptoms, emotional distress, side effects, self-esteem, emotion and avoidance related coping styles, expressed emotion, and other social support. Determinants of change in QOL of patients were different being in hospital or out of hospital in the real world. No significant association of age, education, and follow up duration, with general QOL. Based on obtained data three types of overlapping factors were defined: (1) distressing, and protective; (2) primary and secondary; and (3) factors that remained constant or changed over time. Presented data are discussed within the framework of the Distress/Protection model of QOL. The conceptualization of three types of factors influencing QOL outcomes in this model demonstrates their predictive value, and may assist investigators and mental health workers in the interpretation of QOL data that may be used to improve patients' QOL outcomes.

Adolescent↗

PubMed2006

Changes in stability of first-admission psychiatric diagnoses over 14 years, based on cross-sectional data at three time points.

BACKGROUND: Stability of diagnoses over time is an important criterion of reliability of any diagnostic system. AIMS: To compare the stability of diagnoses among hospitalized psychiatric patients over 14 years, based on cross-sectional data at three time points. METHOD: Diagnoses extracted from the National Psychiatric Case Register concerning psychiatric patients first admitted during 1989 (n=2996) were compared to those who were admitted during 1996 (n=3021) and 2003 (n=4041). Stability of diagnostic categories was measured by positive predictive value of admission diagnosis at discharge from hospital. RESULTS: There was no significant difference in diagnostic stability for most diagnostic categories between 1989 and 1996 patient cohorts. However, over the seven following years (cohort 2003) the diagnostic stability had been substantially increased: by 19% for affective disorders, by 18% for childhood disorders, by 17% for organic conditions, by 14% for neurotic disorders, by 12% for both schizophrenia and drug and alcohol dependence. CONCLUSIONS: In long-term perspective, reliability of most diagnostic categories of mental disorders has clearly improved.

Adolescent↗

PubMed2005

Familiality in a five-factor model of schizophrenia psychopathology: findings from a 16-month follow-up study.

We sought to examine stability associations between family history and variability of schizophrenia symptoms repeatedly examined during a naturalistic follow-up study. The Positive and Negative Syndrome Scale, the Insight and Treatment Attitudes Questionnaire, and the Abnormal Involuntary Movement Scale were administered to 69 patients with familial and 79 patients with sporadic schizophrenia, at hospital admission and at stabilization stage (about 16 months later). Analysis of covariance was applied to identify the association of symptom factors with familiality of schizophrenia. We found that schizophrenia patients with positive family histories had significantly higher dysphoric, activation and negative factors. However, familiality of activation and negative factors were dependent on additional variables such as age of onset (both factors), baseline ratings, insight, and side effects (negative factor). No significant association of family history with intensity of positive and autistic preoccupation factors was found. Familial schizophrenia is characterized by higher severity of dysphoric mood factors that may represent impaired emotional reactivity. It is suggested that dysphoric mood may be a useful phenotype for molecular genetic studies of schizophrenia with positive family history.

Adolescent↗

PubMed2005

Alterations in DHEA metabolism in schizophrenia: two-month case-control study.

OBJECTIVE: The goals of this study were to determine whether alterations in serum dehydroepiandrosterone (DHEA), its sulfated conjugate (DHEAS), androstenedione, testosterone, and progesterone concentrations occur in schizophrenia patients compared with healthy controls over two months, and their associations with psychopathology, emotional distress, and antipsychotic treatment. METHOD: Serum hormones were repeatedly determined for 21 antipsychotic-treated male DSM-IV schizophrenia patients and 14 healthy controls. Observations were at four time points: upon entry into the study, and after 2, 4 and 8 weeks. RESULTS: In schizophrenia patients compared with healthy controls serum concentration of DHEA and androstenedione found increased, but that of DHEAS decreased, while progesterone and testosterone showed normal levels. Schizophrenia patients were also characterized by elevated androstenedione/DHEAS molar ratios, and reduced DHEAS/DHEA and testosterone/androstenedione molar ratios compared with healthy controls. Concentrations and molar ratios of serum hormones did not significantly change during the study either among schizophrenia patients, or healthy controls. Among patients alterations in DHEA, DHEAS and androstenedione were associated with emotional distress, anxiety, dysphoric mood, positive and activation symptoms, serum prolactin levels, but were not related to age, antipsychotic agents, and extrapyramidal side effects. CONCLUSIONS: Alterations in DHEA metabolism in schizophrenia are attributed to the distress, anxiety, severity of symptoms, prolactin levels, and may represent a marker for impaired hormonal responses to stress. These findings should be considered when evaluating the discrepancies in DHEA studies in schizophrenia.

Adult↗

PubMed2005

Condensed version of the Quality of Life Scale for schizophrenia for use in outcome studies.

The Quality of Life Scale (QLS(21)) is widely used in clinical trials involving schizophrenia patients. This study aimed to identify a core subset of QLS(21) items that maintains the validity and psychometric properties of the complete version. A parsimonious subset of items from the QLS(21) that can accurately predict the total scale score was sought and evaluated in 133 schizophrenia patients, using the heuristic algorithm for a regression model. Two additional data sets were used for model validation: a subset of 124 patients who participated in the model construction and who completed the QLS(21) 1 year later as well as a new sample of 40 inpatients. Patients were examined with the Positive and Negative Syndrome Scale (PANSS), the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), the Talbieh Brief Distress Inventory (TBDI), the Extrapyramidal Symptom Rating Scale (ESRS) and the Global Assessment of Functioning Scale (GAF). Using only five QLS items (social initiatives, adequacy, acquaintances, motivation, and time utilization; QLS(5)) as predictors, the correlation was 0.9805 between the predicted and true QLS totals. Two validation samples confirmed this finding. Additional analyses indicate that the QLS(5) exhibited similar performance to the QLS(21) regarding construct validity, test-retest reliability and responsiveness to changes over time. Thus, the five-item condensed Quality of Life Scale for schizophrenia maintains the validity of the full QLS, and has the advantage of shorter administration time. Utilization of the revised QLS(5) in routine care and clinical trials may potentially facilitate evaluation of treatment outcomes in schizophrenia.

Adolescent↗

PubMed2005

Quality of life and temperament factors in schizophrenia: comparative study of patients, their siblings and controls.

This study aimed to determine which temperament factors are associated with quality of life (QOL) in schizophrenia based on a triplet design comparing patients with their non-affected siblings and healthy control subjects. Forty-seven DSM-IV clinically stable schizophrenia outpatients, 47 non-affected siblings, and 56 non-patients matched for gender and age were evaluated using the Tridimensional Personality Questionnaire and the Quality of Life Enjoyment and Life Satisfaction Questionaire. As expected, schizophrenia patients reported significantly poorer QOL in most specific domains and in general. They also revealed significantly higher scores on harm avoidance and scored lower on reward dependence, than both their siblings and controls. Tridimensional Personality Questionnaire temperament factors revealed no differences between the controls and the siblings. When differences between patients, their siblings and controls were adjusted for gender, age at examination, and education, ANOVA demonstrated that temperament factors contributed to poor satisfaction with physical health, social relationships and subjective feelings in schizophrenia patients. Harm avoidance was associated with general QOL independent of severity of psychopathology. Thus, this study suggests that temperament factors that are not necessarily part of the deterioration process of the illness are associated with the quality of life of schizophrenia patients. These and other non-illness related factors should be considered when evaluating quality of life outcomes in intervention studies.

Case-Control Studies↗

PubMed2005

Validity of an abbreviated quality of life enjoyment and satisfaction questionnaire (Q-LES-Q-18) for schizophrenia, schizoaffective, and mood disorder patients.

We sought to identify a core subset of Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) items that maintains the validity and psychometric properties of the basic version. A parsimonious subset of items from the Q-LES-Q that can accurately predict the basic Q-LES-Q domain mean scores was sought and evaluated in 339 inpatients meeting DSM-IV criteria for schizophrenia, schizoaffective, and mood disorders. Three additional data sets were used for validation. Assessments included Q-LES-Q, Quality of Life Scale, Lancashire Quality of Life Profile, rating scales for psychopathology, medication side effects, and self-reported emotional distress, self-esteem, self-efficacy, and social support. We found that 18-items predicted basic Q-LES-Q domains (physical health, subjective feelings, leisure time activities, social relationships) and general index scores with high accuracy. Q-LES-Q-18 showed high reliability, validity, and stability of test-retest ratings. Thus, Q-LES-Q-18, a brief, self-administered questionnaire may aid in monitoring quality of life outcomes of schizophrenia, schizoaffective, and mood disorder patients.

Adult↗

PubMed2005

Cortisol/dehydroepiandrosterone ratio and responses to antipsychotic treatment in schizophrenia.

Dehydroepiandrosterone (DHEA) or their sulfate conjugate (DHEAS) (together abbreviated DHEA(S)) exert multiple effects in the central nervous system, and may be involved in the pathophysiological processes in schizophrenia. This prospective study aimed to investigate whether serum cortisol/DHEA(S) molar ratios are associated with response to antipsychotic treatment during the exacerbation of schizophrenia. Serum DHEA(S) and cortisol were determined at baseline, and 2 and 4 weeks later for 43 medicated schizophrenia inpatients with acute exacerbation. The patients were treated with stable doses of antipsychotic agents up to 2 weeks prior to entering the study and for the 4-week duration of the study after which they were classified as either responders or nonresponders to treatment. Findings suggest that responders had significantly higher serum cortisol levels and cortisol/DHEA(S) ratios compared with nonresponders. These differences remained significant at three time points controlling for gender, age, severity of symptoms and emotional distress, benzodiazepines, type or dosage of antipsychotic agents, and background variables. The logistic regression model shows advantages of both cortisol/DHEA(S) molar ratios vs serum cortisol and DHEA(S) concentrations for prediction of responsivity to antipsychotic treatment. No significant canonical correlations were observed between changes from baseline through end-of-study in hormonal values and severity of symptoms and emotional distress among responders and nonresponders. Thus, these data provide evidence that elevated serum cortisol and cortisol/DHEA(S) ratios may serve as markers of biological mechanisms that are involved in responsivity of schizophrenia patients to antipsychotic treatment.

Adult↗

PubMed2004

Temperament types are associated with weak self-construct, elevated distress and emotion-oriented coping in schizophrenia: evidence for a complex vulnerability marker?

Knowledge concerning temperament factors involved in vulnerability to schizophrenia is limited. We hypothesized that temperament and self-variables (emotional distress, coping styles, self-efficacy and self-esteem) might present a complex trait marker for underlying vulnerability to schizophrenia. We sought to (1) assess temperament dimensions and types in schizophrenia patients and healthy controls using the Tridimensional Personality Questionnaire (TPQ), and (2) explore their association with symptom dimensions, emotional distress, coping styles, self-constructs, demographic and background variables. We evaluated 90 consecutively recruited DSM-IV schizophrenia patients and 136 healthy controls matched for gender and age. We found that the harm avoidance (HA) factor was higher, while reward dependence (RD) was lower in schizophrenia patients than in healthy controls. Relationships of negative symptoms to novelty seeking (NS) and general psychopathology with both NS and HA show a confounding relation to self-variables. TPQ temperament types were defined by dichotomization into high and low according to medians of the three TPQ temperament dimensions. The odds ratios for the HA and HA/NS temperament types were significantly higher, while the NS/RD type was lower in schizophrenia patients than in healthy controls. HA/NS, HA/RD and high-HA/NS/RD types revealed higher scores for emotional distress, emotion-oriented coping and lower scores on self-constructs. No links were found between temperament types and schizophrenia symptom dimensions, task and avoidance oriented coping, or demographic and background variables. Thus, our findings strengthen the hypothesis that temperament types, when associated with elevated emotional distress, emotion-oriented coping and weak self-constructs, might represent a complex trait marker for underlying vulnerability to schizophrenia.

Adaptation, Psychological↗

PubMed2004

Is the G72/G30 locus associated with schizophrenia? single nucleotide polymorphisms, haplotypes, and gene expression analysis.

BACKGROUND: The genes G72/G30 were recently implicated in schizophrenia in both Canadian and Russian populations. We hypothesized that 1) polymorphic changes in this gene region might be associated with schizophrenia in the Ashkenazi Jewish population and that 2) changes in G72/G30 gene expression might be expected in schizophrenic patients compared with control subjects. METHODS: Eleven single nucleotide polymorphisms (SNPs) encompassing the G72/G30 genes were typed in the genomic deoxyribonucleic acid (DNA) from 60 schizophrenic patients and 130 matched control subjects of Ashkenazi ethnic origin. Case-control comparisons were based on linkage disequilibrium (LD) and haplotype frequency estimations. Gene expression analysis of G72 and G30 was performed on 88 postmortem dorsolateral prefrontal cortex samples. RESULTS: Linkage disequilibrium analysis revealed two main SNP blocks. Haplotype analysis on block II, containing three SNPs external to the genes, demonstrated an association with schizophrenia. Gene expression analysis exhibited correlations between expression levels of the G72 and G30 genes, as well as a tendency toward overexpression of the G72 gene in schizophrenic brain samples of 44 schizophrenic patients compared with 44 control subjects. CONCLUSIONS: It is likely that the G72/G30 region is involved in susceptibility to schizophrenia in the Ashkenazi population. The elevation in expression of the G72 gene coincides with the glutamatergic theory of schizophrenia.

Adolescent↗

PubMed2004

Elevation of the cortisol/dehydroepiandrosterone ratio in schizophrenia patients.

Dehydroepiandrosterone (DHEA) and its sulfate derivative DHEA-S are neurosteroids, produced in the brain, and neuroactive steroids, produced in the adrenals and affecting the brain. We compared the ratios of serum cortisol/DHEA or DHEA-S in schizophrenia patients with normal subjects, and determined the correlation of these ratios with psychopathology and distress. Early morning plasma concentrations of DHEA, DHEA-S, and cortisol were determined by radioimmunassay in 40 medicated schizophrenia inpatients, and 15 healthy subjects with similar age and sex distribution. Subjects were assessed for psychopathology using the Positive and Negative Syndrome Scale (PANSS) and the Montgomery and Asberg Depression Rating Scale (MADRS), anxiety, anger, emotional and somatic distress levels. Schizophrenia inpatients demonstrated significantly higher levels of state and trait anxiety, anger expression index, emotional and somatic self-reported distress scores. Cortisol/DHEA and cortisol/DHEA-S ratios were significantly higher in schizophrenia patients than in healthy comparison subjects. Both ratios correlated positively with age and duration of illness; cortisol/DHEA-S ratio also showed positive association with age of illness onset. When age, illness duration and age of onset were controlled, cortisol/DHEA-S ratio significantly correlated with severity of depression (MADRS, r=0.33, p=0.048), state and trait anxiety (r=0.43, p=0.008 and r=0.40, p=0.014, respectively), trait anger (r=0.41, p=0.012), angry temperament (r=0.46, p=0.004), anger expression index (r=0.36, p=0.033), and hostility (r=0.42, p=0.010). No significant association was found between these ratios and severity of psychopathology, and type or dosage of antipsychotic agents. Thus, elevated cortisol/DHEA and/or cortisol/DHEA-S ratios in schizophrenia patients are positively associated with higher scores for anxiety and anger, depression and hostility, age and age of onset/duration of illness, but are independent of severity of psychopathology (PANSS) and antipsychotic treatment.

Adult↗

PubMed2004

Perceived quality of life in schizophrenia: relationships to sleep quality.

We examined the relationship between perceived quality of life (QOL) and subjective quality of sleep among schizophrenia patients, and its relation to symptom severity, side effects and emotional distress. One hundred and forty five schizophrenia patients were comprehensively evaluated with standardized measures of symptom severity, adverse effects, emotional distress, QOL, and sleep quality (the Pittsburgh Sleep Quality Index, PSQI). Partial correlation and multiple regression analyses were performed. Poor sleepers reported lower mean scores on all QOL domains, they were more depressed and distressed, and had more adverse effects to medications with concomitant distress than good sleepers. The negative relationship between complaints of poor sleep quality and QOL measures remained significant when the confounding effect of depression, side effects, and distress was partialled from the correlation matrix. Daytime dysfunction (a component of the PSQI) accounted for 12.6% of the variance in QOL index scores. Thus, poor QOL reported by schizophrenia patients is substantially associated with poor sleep quality. This association appears both independently and synergistically with depression, distress and side effects of medications.

Adolescent↗

PubMed2004

Aggregability of red blood cells of schizophrenia patients with negative syndrome is selectively enhanced.

Schizophrenia patients can be categorized into positive and negative syndromes (PS and NS) by the behavioral criteria of the Positive and Negative Syndrome Scale (PANSS), but these symptoms can also be evaluated as a continuous trait. Both types exhibit cerebral microcirculatory disorders, which are ameliorated by drug treatment in PS but not in NS patients. Red blood cell (RBC) aggregability plays a major role in the microcirculation. Previously reported changes in RBC membrane phospholipid composition indicate a difference in aggregability between RBCs of NS and PS patients. In this study the aggregability of PS RBCs and NS RBCs was analyzed using a computerized cell flow-properties analyzer, as a physiological marker of NS and PS. Results showed that while the aggregability of PS RBCs was normal, that of NS RBCs was markedly enhanced and strongly correlated with the NS score. The results exhibited stability and reproducibility over 1 to 8 weeks test-retest and were independent of gender, age at testing and onset of illness, fibrinogen levels, smoking, and current medication. NS RBCs have constitutively elevated aggregability, which can contribute to cerebral microcirculatory disorders and may be a biological marker for distinguishing between PS and NS in genetic studies of schizophrenia.

Adult↗

PubMed2004

Subjective response to antipsychotics of schizophrenia patients treated in routine clinical practice: a naturalistic comparative study.

In routine practice, subjective response to antipsychotics is becoming a critical outcome measure among schizophrenia patients. This study sought to compare subjective response to atypical (risperidone and olanzapine) and typical antipsychotic drugs. Using a naturalistic cross-sectional design, we examined subjective response to antipsychotics (satisfaction with medication and subjective tolerability), psychopathology, side effects, emotional distress, and awareness in schizophrenia patients stabilized on atypical (n = 78) and typical (n = 55) drugs. Analysis of variance and multiple regression analysis were applied. We found that atypical drugs were superior to typical antipsychotics in both measures of subjective response, which were positively correlated (r = 0.52, P < 0.001). Poor subjective response was associated with severity of emotional distress, negative, and activation symptoms in the atypical group and with extrapyramidal side effects and positive symptoms in the typical group. Awareness of treatment is a positive factor that accounted for 20% and 34% of variation in the subjective responses to atypical and typical antipsychotic drugs, respectively. Demographic variables, age of onset, illness duration, and adjunctive drugs did not relate significantly to subjective response to antipsychotic drugs. Thus, atypical drugs are characterized by better subjective response compared with typical antipsychotics; their determinants differed considerably. Satisfaction with medication together with subjective tolerability needs to be considered in clinical trials.

Adult↗

PubMed2004

Quality of life outcomes of risperidone, olanzapine, and typical antipsychotics among schizophrenia patients treated in routine clinical practice: a naturalistic comparative study.

Findings in previous studies investigating the beneficial effect of risperidone and olanzapine versus typical antipsychotics on quality of life (QOL) are controversial since they did not adjust for various factors contributing to QOL. To test this assumption in a naturalistic cross-sectional design, we evaluated general and domain-specific QOL scores for baseline data of schizophrenia outpatients stabilized on atypical (N = 78, risperidone or olanzapine) and typical (N = 55) agents. Self-report and observer-rated QOL outcomes of both risperidone and olanzapine with typical antipsychotic therapy were compared across demographic, illness-related, and treatment-related factors using analysis of variance, multivariate analysis of variance, and correlation analysis. No significant differences were found in QOL outcomes of risperidone-treated and olanzapine-treated patients. Both self-report and rater-observed QOL measures indicated superiority of atypical over typical antipsychotic agents after adjusting for daily doses, duration of treatment, subjective tolerability, and adjuvant antidepressants. Lower daily doses and longer antipsychotic treatment were associated with better QOL. Self-report and observer-rated QOL scores correlated positively (r = 0.64, P < 0.001). Gender, marital status, age, education, living arrangement and employment status, age of onset, illness duration, symptom severity, emotional distress, subtypes of schizophrenia, and side effects did not affect QOL outcomes in either group. Risperidone and olanzapine revealed an advantage over typical agents in terms of QOL. Findings suggest that when calculating the beneficial effects of atypical antipsychotic therapy on QOL outcomes, daily doses, duration of treatment, and subjective tolerability may be intervening variables and should be adjusted accordingly to clearly appreciate benefits of atypical antipsychotics.

Adult↗

PubMed2003

Association study of CAG repeats in the KCNN3 gene in Israeli patients with major psychosis.

OBJECTIVES: Several studies reported contradictory findings regarding the association of major psychosis with CAG repeats in the KCNN3 gene. We investigated the contribution of the CAG repeat at the KCNN3 gene, localized to chromosome 1q21.3, to the genetic susceptibility for schizophrenia, schizoaffective and bipolar disorders. METHODS: Analysis of the number of CAG repeats and the differences in allele length were performed for Israeli Ashkenazi Jews, non-Ashkenazi Jews, and Arabs diagnosed with major psychosis (n=181) versus matched ethnic controls (n=207). RESULTS: We found no significant difference in the number of CAG repeats between the entire sample of patients and controls. However, an analysis of the differences of allele length revealed a significantly greater number of patients with identical allele length (43.1%) when compared with normal controls (30.4%). Furthermore, an earlier age of non-paranoid schizophrenia onset was found associated with differences in allele sizes. There were no significant differences in the number of CAG repeats and the differences in allele length when subjects were grouped according to gender, ethnic origins of their parents, family history, and diagnostic groups. CONCLUSIONS: Our results support the hypothesis that a contribution of the KCNN3 gene to genetic susceptibility to major psychosis and their phenotypic polymorphism may be related to the difference of allele length rather than to the number of CAG repeats.

Arabs↗