Failure to find DUP25 in patients with anxiety disorders,in control individuals,or in previously reported positive control cell lines

Investigation of the co-occurrence of panic and phobic disorders with joint laxity led to the identification of various forms of interstitial duplications involving human chromosome 15q24-q26 (named "DUP25") in a Spanish population. DUP25 was observed in 68 of 70 (97%) patients assigned the diagnosis panic disorder/agoraphobia. DUP25 was also found in 14 of 189 (7%) control individuals. In the present study, we replicated the experimental conditions described by Gratacòs and colleagues in which fluorescence in situ hybridization was used to examine metaphase chromosomes of patients with panic disorder/social phobia and of control individuals from a southern region of the United Kingdom, the primary aim being to determine the prevalence of this chromosomal rearrangement in a geographically and ethnically distinct population. DUP25 was not observed in any of our 16 patients or 40 control samples or in three previously reported DUP25-positive control (Centre d'Etude du Polymorphisme Humain) cell lines, indicating a highly significant difference in the frequency of DUP25 between the study by Gratacòs and colleagues and the present investigation.     

No evidence for DUP25 in patients with panic disorder using a quantitative real-time PCR approach

A duplication of chromosome 15q24-q26 (DUP25) has been reported to be associated with anxiety disorders. We tested for the presence of DUP25 in a sample of 50 patients with panic disorder and 50 controls using a quantitative real-time PCR approach. Contrary to the original finding, our results were compatible with the absence of DUP25, and no significant difference could be detected between patients and controls (P=1.0). Thus, our study does not support the hypothesis of an involvement of DUP25 in panic disorder.     

Redefined genomic architecture in 15q24 directed by patient deletion/duplication breakpoint mapping

We report four new patients with a submicroscopic deletion in 15q24 manifesting developmental delay, short stature, hypotonia, digital abnormalities, joint laxity, genital abnormalities, and characteristic facial features. These clinical features are shared with six recently reported patients with a 15q24 microdeletion, supporting the notion that this is a recognizable syndrome. We describe a case of an ~2.6 Mb microduplication involving a portion of the minimal deletion critical region in a 15-year-old male with short stature, mild mental retardation, attention deficit hyperactivity disorder, Asperger syndrome, decreased joint mobility, digital abnormalities, and characteristic facial features. Some of these features are shared with a recently reported case with a 15q24 microduplication involving the minimal deletion critical region. We also report two siblings and their mother with duplication adjacent and distal to this region exhibiting mild developmental delay, hypotonia, tapering fingers, characteristic facial features, and prominent ears. The deletion and duplication breakpoints were mapped by array comparative genomic hybridization and the genomic structure in 15q24 was analyzed further. Surprisingly, in addition to the previously recognized three low-copy repeat clusters (BP1, BP2, and BP3), we identified two other paralogous low-copy repeat clusters that likely mediated the formation of alternative sized 15q24 genomic rearrangements via non-allelic homologous recombination.     

Psychiatric genetics: a frightful chromosome.

A duplication of part of chromosome 15q, apparently inherited in a non-Mendelian fashion, has been found to be strongly associated with phobic disorders. This unusual genetic mechanism may partly explain the heritability of phobias and other complex traits.     

Respiratory and psychiatric abnormalities in chronic symptomatic hyperventilation.

Many physicians believe that the hyperventilation syndrome is invariably associated with anxiety or undiagnosed organic disease such as asthma and pulmonary embolus, or both. Twenty one patients referred by specialist physicians with unexplained somatic symptoms and unequivocal chronic hypocapnia (resting end tidal Pco2 less than or equal to 4 kPa (30 mm Hg) on repeated occasions during prolonged measurement) were investigated. All but one complained of inability to take a satisfying breath. Standard lung function test results and chest radiographs were normal in all patients, but histamine challenge showed bronchial hyper-reactivity in two of 20 patients tested, and skin tests to common allergens were positive in three of 18. Ventilation-perfusion scanning was abnormal in a further three of 15 patients studied, with unmatched perfusion defects in two and isolated ventilation defects in one. None of the 21 had thyrotoxicosis, severe coronary heart disease, or other relevant cardiovascular abnormalities. Ten of the 21 patients were neurotic and suffered from chronic psychiatric disturbance characterised by anxiety, panic, and phobic symptoms. The remainder had no detectable psychiatric disorders but reported proportionately more somatic than anxiety symptoms. Severe hyperventilation can occur in the absence of formal psychiatric or detectable respiratory or other organic abnormalities. Asthma and pulmonary embolus must be specifically excluded.     

Genome scan for loci predisposing to anxiety disorders using a novel multivariate approach: strong evidence for a chromosome 4 risk locus

We conducted a 10-centimorgan linkage autosomal genome scan in a set of 19 extended American pedigrees (219 subjects) ascertained through probands with panic disorder. Several anxiety disorders--including social phobia, agoraphobia, and simple phobia--in addition to panic disorder segregate in these families. In previous studies of this sample, linkage analyses were based separately on each of the individual categorical affection diagnoses. Given the substantial comorbidity between anxiety disorders and their probable shared genetic liability, it is clear that this method discards a considerable amount of information. In this article, we propose a new approach that considers panic disorder, simple phobia, social phobia, and agoraphobia as expressions of the same multivariate, putatively genetically influenced trait. We applied the most powerful multipoint Haseman-Elston method, using the grade of membership score generated from a fuzzy clustering of these phenotypes as the dependent variable in Haseman-Elston regression. One region on chromosome 4q31-q34, at marker D4S413 (with multipoint and single-point nominal P values < .00001), showed strong evidence of linkage (genomewide significance at P<.05). The same region is known to be the site of a neuropeptide Y receptor gene, NPY1R (4q31-q32), that was recently connected to anxiolytic-like effects in rats. Several other regions on four chromosomes (4q21.21-22.3, 5q14.2-14.3, 8p23.1, and 14q22.3-23.3) met criteria for suggestive linkage (multipoint nominal P values < .01). Family-by-family analysis did not show any strong evidence of heterogeneity. Our findings support the notion that the major anxiety disorders, including phobias and panic disorder, are complex traits that share at least one susceptibility locus. This method could be applied to other complex traits for which shared genetic-liability factors are thought to be important, such as substance dependencies.     

Analysis of TBX1 variation in patients with psychotic and affective disorders

A significant portion of patients with 22q11 deletion syndrome (22q11DS) develop psychiatric disorders, including schizophrenia and other psychotic and affective symptoms, and the responsible gene/s are assumed to also play a significant role in the etiology of nonsyndromic psychiatric disease. The most common psychiatric diagnosis among patients with 22q11DS is schizophrenia, thought to result from neurotransmitter imbalances and also from disturbed brain development. Several genes in the 22q11 region with known or suspected roles in neurotransmitter metabolism have been analyzed in patients with isolated schizophrenia; however, their contribution to the disease remains controversial. Haploinsufficiency of the TBX1 gene has been shown to be sufficient to cause the core physical malformations associated with 22q11DS in mice and humans and via abnormal brain development could contribute to 22q11DS-related and isolated psychiatric disease. 22q11DS populations also have increased rates of psychiatric conditions other than schizophrenia, including mood disorders. We therefore analyzed variations at the TBX1 locus in a cohort of 446 white patients with psychiatric disorders relevant to 22q11DS and 436 ethnically matched controls. The main diagnoses included schizophrenia (n = 226), schizoaffective disorder (n = 67), bipolar disorder (n = 82), and major depressive disorder (n = 29). We genotyped nine tag SNPs in this sample but did not observe significant differences in allele or haplotype frequencies in any of the analyzed groups (all affected, schizophrenia and schizoaffective disorder, schizophrenia alone, and bipolar disorder and major depressive disorder) compared with the control group. Based on these results we conclude that TBX1 variation does not make a strong contribution to the genetic etiology of nonsyndromic forms of psychiatric disorders commonly seen in patients with 22q11DS.     

Subtypes of Ataques de Nervios: The Influence of Coexisting Psychiatric Diagnosis

The current study assesses the relationship between presenting symptomatology of the self-labeled Hispanic popular diagnosis of ataques de nervios and the specific co-morbid psychiatric diagnoses. Hispanic subjects seeking treatment at an anxiety disorders clinic (n = 156) were assessed with a specially designed self-report instrument for both traditional ataque de nervios and panic symptoms, and with structured or semi-structured psychiatric interviews for Axis-I disorders. This report focuses on 102 subjects with ataque de nervios who also met criteria for panic disorder, other anxiety disorders, or an affective disorder. Distinct ataque symptom patterns correlated with co-existing panic disorder, affective disorders, or other anxiety disorders. Individuals with both ataque and panic disorder reported the most asphyxia, fear of dying, and increased fear during their ataques. People with ataques who also met criteria for affective disorder reported the most anger, screaming, becoming aggressive, and breaking things during ataques. Ataque positive subjects with other anxiety disorders were less salient for both panic-like and emotional-anger symptoms. The findings suggest that (a) ataque de nervios is a popular label referring to several distinct patterns of loss of emotional control, (b) the type of loss of emotional control is influenced by the associated psychiatric disorder, and (c) ataque symptom patterns may be a useful clinical marker for detecting psychiatric disorders. Further study is needed to examine the relationship between ataque de nervios and psychiatric disorders, as well as the relationship to cultural, demographic, environmental, and personality factors.     

Molecular analysis of velo-cardio-facial syndrome patients with psychiatric disorders.

Velo-cardio-facial syndrome (VCFS) is characterized by conotruncal cardiac defects, cleft palate, learning disabilities, and characteristic facial appearance and is associated with hemizygous deletions within 22q11. A newly recognized clinical feature is the presence of psychiatric illness in children and adults with VCFS. To ascertain the relationship between psychiatric illness, VCFS, and chromosome 22 deletions, we evaluated 26 VCFS patients by clinical and molecular biological methods. The VCFS children and adolescents were found to share a set of psychiatric disorders, including bipolar spectrum disorders and attention-deficit disorder with hyperactivity. The adult patients, >18 years of age, were affected with bipolar spectrum disorders. Four of six adult patients had psychotic symptoms manifested as paranoid and grandiose delusions. Loss-of-heterozygosity analysis of all 26 patients revealed that all but 3 had a large 3-Mb common deletion. One patient had a nested distal deletion and two did not have a detectable deletion. Somatic cell hybrids were developed from the two patients who did not have a detectable deletion within 22q11 and were analyzed with a large number of sequence tagged sites. A deletion was not detected among the two patients at a resolution of 21 kb. There was no correlation between the phenotype and the presence of the deletion within 22q11. The remarkably high prevalence of bipolar spectrum disorders, in association with the congenital anomalies of VCFS and its occurrence among nondeleted VCFS patients, suggest a common genetic etiology.     

Role of corticotropin releasing factor in anxiety disorders: a translational research perspective

Anxiety disorders are a group of mental disorders that include generalized anxiety disorder (GAD), panic disorder, phobic disorders (e.g., specific phobias, agoraphobia, social phobia) and posttraumatic stress disorder (PTSD). Anxiety disorders are among the most common of all mental disorders and, when coupled with an awareness of the disability and reduced quality of life they convey, they must be recognized as a serious public health problem. Over 20 years of preclinical studies point to a role for the CRF system in anxiety and stress responses. Clinical studies have supported a model of CRF dysfunction in depression and more recently a potential contribution to specific anxiety disorders (i.e., panic disorder and PTSD). Much work remains in both the clinical and preclinical fields to inform models of CRF function and its contribution to anxiety. First, we will review the current findings of CRF and HPA axis abnormalities in anxiety disorders. Second, we will discuss startle reflex measures as a tool for translational research to determine the role of the CRF system in development and maintenance of clinical anxiety.