Multi-ancestry genome-wide association study of major depression aids locus discovery, fine mapping, gene prioritization and causal inference

Most genome-wide association studies (GWAS) of major depression (MD) have been conducted in samples of European ancestry. Here we report a multi-ancestry GWAS of MD, adding data from 21 cohorts with 88,316 MD cases and 902,757 controls to previously reported data. This analysis used a range of measures to define MD and included samples of African (36% of effective sample size), East Asian (26%) and South Asian (6%) ancestry and Hispanic/Latin American participants (32%). The multi-ancestry GWAS identified 53 significantly associated novel loci. For loci from GWAS in European ancestry samples, fewer than expected were transferable to other ancestry groups. Fine mapping benefited from additional sample diversity. A transcriptome-wide association study identified 205 significantly associated novel genes. These findings suggest that, for MD, increasing ancestral and global diversity in genetic studies may be particularly important to ensure discovery of core genes and inform about transferability of findings.

Psychosis Endophenotypes: A Gene-Set-Specific Polygenic Risk Score Analysis

BACKGROUND AND HYPOTHESIS

Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes.

STUDY DESIGN

We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score.

STUDY RESULTS

After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: -1.15 µV; 95% CI: -1.70 to -0.59 µV; P = 6 × 10-5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores.

CONCLUSIONS

Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models.

Multiple psychiatric polygenic risk scores predict associations between childhood adversity and bipolar disorder

BACKGROUND

It remains unclear how adverse childhood experiences (ACE) and increased genetic risk for bipolar disorder (BD) interact to influence BD symptom outcomes. Here we calculated multiple psychiatric polygenic risk scores (PRS) and used the measures of ACE to understand these gene-environment interactions.

METHOD

885 BD subjects were included for analyses. BD, ADHD, MDD and SCZ PRSs were calculated using the PRS-CS-auto method. ACEs were evaluated using the Children Life Event Questionnaire (CLEQ). Participants were divided into groups based on the presence of ACE and the total number of ACEs. The associations between total ACE number, PRSs and their interactions were evaluated using multiple linear and logistic regressions. Secondary analyses were performed to evaluate the influence of ACE and PRS on sub-phenotypes of BD.

RESULTS

The number of ACEs increased with the ADHD PRS. BD participants who had ACEs showed an earlier age of BD onset and higher odds of having rapid cycling. Increased BD PRS was associated with increased odds of developing psychotic symptoms. Higher ADHD PRS was associated with increased odds of having rapid cycling. No prediction effect was observed from MDD and SCZ PRS. And, we found no significant interaction between ACE numbers and any of the PRSs in predicting any selected BD sub-phenotypes.

LIMITATIONS

The study was limited by sample size, ACE definition, and cross-sectional data collection method.

CONCLUSIONS

The findings consolidate the importance of considering multiple psychiatric PRSs in predicting symptom outcomes among BD patients.

Investigating the association between schizophrenia and distance visual acuity: Mendelian randomisation study

BACKGROUND

Increased rates of visual impairment are observed in people with schizophrenia.

AIMS

We assessed whether genetically predicted poor distance acuity is causally associated with schizophrenia, and whether genetically predicted schizophrenia is causally associated with poorer visual acuity.

METHOD

We used bidirectional, two-sample Mendelian randomisation to assess the effect of poor distance acuity on schizophrenia risk, poorer visual acuity on schizophrenia risk and schizophrenia on visual acuity, in European and East Asian ancestry samples ranging from approximately 14 000 to 500 000 participants. Genetic instrumental variables were obtained from the largest available summary statistics: for schizophrenia, from the Psychiatric Genomics Consortium; for visual acuity, from the UK Biobank; and for poor distance acuity, from a meta-analysis of case-control samples. We used the inverse variance-weighted method and sensitivity analyses to test validity of results.

RESULTS

We found little evidence that poor distance acuity was causally associated with schizophrenia (odds ratio 1.00, 95% CI 0.91-1.10). Genetically predicted schizophrenia was associated with poorer visual acuity (mean difference in logMAR score: 0.024, 95% CI 0.014-0.033) in European ancestry samples, with a similar but less precise effect that in smaller East Asian ancestry samples (mean difference: 0.186, 95% CI -0.008 to 0.379).

CONCLUSIONS

Genetic evidence supports schizophrenia being a causal risk factor for poorer visual acuity, but not the converse. This highlights the importance of visual care for people with psychosis and refutes previous hypotheses that visual impairment is a potential target for prevention of schizophrenia.

The APPLE Tree programme: Active Prevention in People at risk of dementia through Lifestyle, bEhaviour change and Technology to build REsiliEnce-randomised controlled trial

BACKGROUND

Large-scale trials of multidomain interventions show that modifying lifestyle and psychological risk factors can slow cognitive decline. We aim to determine if a lower intensity, personally tailored secondary dementia prevention programme for older people with subjective or mild objective memory decline, informed by behaviour change theory, reduces cognitive decline over 2 years.

METHODS

A multi-site, single-blind randomised controlled trial recruiting 704 older adults at high dementia risk due to mild cognitive impairment (MCI) or subjective cognitive decline (SCD). Participants are randomised using 1:1 allocation ratio to the APPLE Tree intervention versus control arm (dementia prevention information), stratified by site. The intervention explores and implements strategies to promote healthy lifestyle, increase pleasurable activities and social connections and improve long-term condition self-management. Two facilitators trained and supervised by a clinical psychologist deliver ten, 1-h group video call sessions over 6 months (approximately every fortnight), video-call 'tea breaks' (less structured, facilitated social sessions) in intervening weeks and individual goal-setting phone calls every 2 weeks. From 6 to 12 months, participants meet monthly for 'tea breaks', with those not attending receiving monthly goal-setting phone calls. Participants receive a food delivery, pedometer and website access to cognitive training and information about lifestyle modification. Follow-ups for all outcome measures are at 12 and 24 months. The primary outcome is cognition (Neuropsychological Test Battery (NTB) score) at 24 months. Secondary outcomes are quality of life, cost per quality-adjusted life year (QALY) and wellbeing and lifestyle factors the intervention targets (diet, vascular risk, body weight, activity, sleep, anxiety, depression, social networks and loneliness, alcohol intake and smoking). Participants from purposively selected sites participate in qualitative process evaluation interviews, which will be analysed using thematic analytic methods.

DISCUSSION

If effective, the intervention design, involving remote delivery and non-clinical facilitators, would facilitate intervention roll-out to older people with memory concerns.

TRIAL REGISTRATION

ISRCTN17325135 . Registration date 27 November 2019.

The Genetic Architecture of Depression in Individuals of East Asian Ancestry: A Genome-Wide Association Study

Importance

Most previous genome-wide association studies (GWAS) of depression have used data from individuals of European descent. This limits the understanding of the underlying biology of depression and raises questions about the transferability of findings between populations.

Objective

To investigate the genetics of depression among individuals of East Asian and European descent living in different geographic locations, and with different outcome definitions for depression.

Design, Setting, and Participants

Genome-wide association analyses followed by meta-analysis, which included data from 9 cohort and case-control data sets comprising individuals with depression and control individuals of East Asian descent. This study was conducted between January 2019 and May 2021.

Exposures

Associations of genetic variants with depression risk were assessed using generalized linear mixed models and logistic regression. The results were combined across studies using fixed-effects meta-analyses. These were subsequently also meta-analyzed with the largest published GWAS for depression among individuals of European descent. Additional meta-analyses were carried out separately by outcome definition (clinical depression vs symptom-based depression) and region (East Asian countries vs Western countries) for East Asian ancestry cohorts.

Main Outcomes and Measures

Depression status was defined based on health records and self-report questionnaires.

Results

There were a total of 194 548 study participants (approximate mean age, 51.3 years; 62.8% women). Participants included 15 771 individuals with depression and 178 777 control individuals of East Asian descent. Five novel associations were identified, including 1 in the meta-analysis for broad depression among those of East Asian descent: rs4656484 (β = -0.018, SE = 0.003, P = 4.43x10-8) at 1q24.1. Another locus at 7p21.2 was associated in a meta-analysis restricted to geographically East Asian studies (β = 0.028, SE = 0.005, P = 6.48x10-9 for rs10240457). The lead variants of these 2 novel loci were not associated with depression risk in European ancestry cohorts (β = -0.003, SE = 0.005, P = .53 for rs4656484 and β = -0.005, SE = 0.004, P = .28 for rs10240457). Only 11% of depression loci previously identified in individuals of European descent reached nominal significance levels in the individuals of East Asian descent. The transancestry genetic correlation between cohorts of East Asian and European descent for clinical depression was r = 0.413 (SE = 0.159). Clinical depression risk was negatively genetically correlated with body mass index in individuals of East Asian descent (r = -0.212, SE = 0.084), contrary to findings for individuals of European descent.

Conclusions and Relevance

These results support caution against generalizing findings about depression risk factors across populations and highlight the need to increase the ancestral and geographic diversity of samples with consistent phenotyping.

Longitudinal association of apolipoprotein E and sleep with incident dementia

INTRODUCTION

Few longitudinal studies have explored the association between apolipoprotein E gene (APOE) status, sleep disturbances, and incident dementia among middle-aged participants.

METHODS

Cox regression analyses explored the association of sleep duration, insomnia, and daytime napping with incident all-cause dementia and their interaction with APOE genetic risk among 397,777 middle-aged adults.

RESULTS

During a median of 10.8 years follow-up, sleeping more or fewer than 7 hours was associated with a higher dementia risk (hazard ratio [HR] for 5 vs 7 hours: 1.35, 95% confidence interval [CI] 1.11-1.64; HR for 9 vs 7 hours: 1.59; 95% CI 1.37-1.85) as was daytime napping (HR for often/all of the time vs never/rarely: 1.67; 95% CI 1.37-2.03). Stratified analyses revealed that the effects of sleep disturbances were similar across all APOE genetic risk groups.

DISCUSSION

Short and long sleep duration and daytime napping in middle-aged individuals are associated with the development of dementia in later life. Sleep duration and quality are important for everyone regardless of their genetic risk by APOE genotype.

DNA methylation meta-analysis reveals cellular alterations in psychosis and markers of treatment-resistant schizophrenia

We performed a systematic analysis of blood DNA methylation profiles from 4483 participants from seven independent cohorts identifying differentially methylated positions (DMPs) associated with psychosis, schizophrenia, and treatment-resistant schizophrenia. Psychosis cases were characterized by significant differences in measures of blood cell proportions and elevated smoking exposure derived from the DNA methylation data, with the largest differences seen in treatment-resistant schizophrenia patients. We implemented a stringent pipeline to meta-analyze epigenome-wide association study (EWAS) results across datasets, identifying 95 DMPs associated with psychosis and 1048 DMPs associated with schizophrenia, with evidence of colocalization to regions nominated by genetic association studies of disease. Many schizophrenia-associated DNA methylation differences were only present in patients with treatment-resistant schizophrenia, potentially reflecting exposure to the atypical antipsychotic clozapine. Our results highlight how DNA methylation data can be leveraged to identify physiological (e.g., differential cell counts) and environmental (e.g., smoking) factors associated with psychosis and molecular biomarkers of treatment-resistant schizophrenia.

Predictors for a dementia gene mutation based on gene-panel next-generation sequencing of a large dementia referral series

Next-generation genetic sequencing (NGS) technologies facilitate the screening of multiple genes linked to neurodegenerative dementia, but there are few reports about their use in clinical practice. Which patients would most profit from testing, and information on the likelihood of discovery of a causal variant in a clinical syndrome, are conspicuously absent from the literature, mostly for a lack of large-scale studies. We applied a validated NGS dementia panel to 3241 patients with dementia and healthy aged controls; 13,152 variants were classified by likelihood of pathogenicity. We identified 354 deleterious variants (DV, 12.6% of patients); 39 were novel DVs. Age at clinical onset, clinical syndrome and family history each strongly predict the likelihood of finding a DV, but healthcare setting and gender did not. DVs were frequently found in genes not usually associated with the clinical syndrome. Patients recruited from primary referral centres were compared with those seen at higher-level research centres and a national clinical neurogenetic laboratory; rates of discovery were comparable, making selection bias unlikely and the results generalisable to clinical practice. We estimated penetrance of DVs using large-scale online genomic population databases and found 71 with evidence of reduced penetrance. Two DVs in the same patient were found more frequently than expected. These data should provide a basis for more informed counselling and clinical decision making.

APPLE-Tree (Active Prevention in People at risk of dementia: Lifestyle, bEhaviour change and Technology to REducE cognitive and functional decline) programme: Protocol

BACKGROUND

Observational studies indicate that approximately a third of dementia cases are attributable to modifiable cardiometabolic, physical and mental health, and social and lifestyle risk factors. There is evidence that intensive behaviour change interventions targeting these factors can reduce cognitive decline. [Figure: see text] METHODS AND ANALYSIS: We will design and test a low intensity, secondary dementia-prevention programme (Active Prevention in People at risk of dementia: Lifestyle, bEhaviour change and Technology to REducE cognitive and functional decline, "APPLE-Tree") to slow cognitive decline in people with subjective cognitive decline with or without objective cognitive impairment. We will embed our work within social science research to understand how dementia prevention is currently delivered and structured. We will carry out systematic reviews and around 50 qualitative interviews with stakeholders, using findings to coproduce the APPLE-Tree intervention. We plan a 10-session group intervention, involving personalised goal-setting, with individual sessions for those unable or unwilling to attend groups, delivered by psychology assistants who will be trained and supervised by clinical psychologists. The coproduction group (including public and patient involvement [PPI], academic and clinical/third-sector professional representatives) will use the Behaviour Change Wheel theoretical framework to develop it. We will recruit and randomly allocate 704 participants, 1:1 to the intervention: informational control group. This sample size is sufficient to detect a between-group difference at 2 years of 0.15 on the primary outcome (cognition: modified neuropsychological test battery; 90% power, 5% significance, effect size 0.25, SD 0.6).

DISSEMINATION

We will work with Public Health England and third-sector partners to produce an effective national implementation approach, so that if our intervention works, it is used in practice.

Communication and understanding of mild cognitive impairment diagnoses

BACKGROUND

Communication of mild cognitive impairment (MCI) diagnoses is challenging due to its heterogeneity and unclear prognosis.

AIM

To identify how MCI is communicated and to explore the relationship with patient and companion understanding.

METHOD

Conversation analysis identified whether MCI was named and explained in 43 video recorded diagnosis feedback meetings. Afterward, patients and companions were asked to name the diagnosis to assess understanding.

RESULTS

Mild cognitive impairment was not named in 21% meetings. Symptoms were explained as (a) a result of vascular conditions (49%), (b) a stage between normal ageing and dementia (30%), or (c) caused by psychological factors (21%). Fifty-four percentage of prognosis discussions included mention of dementia. There was no association between symptom explanations and whether prognosis discussions included dementia. Fifty-seven percentage patients and 37% companions reported not having or not knowing their diagnosis after the meeting. They were more likely to report MCI when prognosis discussions included dementia.

CONCLUSIONS

Doctors offer three different explanations of MCI to patients. The increased risk of dementia was not discussed in half the diagnostic feedback meetings. This is likely to reflect the heterogeneity in the definition, cause and likely prognosis of MCI presentations. Clearer and more consistent communication, particularly about the increased risk of dementia, may increase patient understanding and enable lifestyle changes to prevent some people progressing to dementia.

Ultra-Rare Genetic Variation in the Epilepsies: A Whole-Exome Sequencing Study of 17,606 Individuals

Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA_A receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.

Involving patients with dementia in decisions to initiate treatment: effect on patient acceptance, satisfaction and medication prescription

BACKGROUND

Shared decision-making is advocated but may be affected by cognitive impairment. Measures of shared decision-making provide global descriptions of communication without detailed analysis of the subtle ways in which doctors invite patient input.AimsWe aimed to explore medication decisions in dementia, using a standardised Treatment Recommendation Coding Scheme.

METHOD

We analysed 71 video-recorded dementia diagnostic meetings from nine memory clinics. Recommendations were coded as pronouncements ('I will start you on medication'), proposals ('Shall we try medication?'), suggestions ('Would you like to try medication?'), offers ('I can prescribe medication') or assertions ('There is medication'). Patient responses were coded as acceptance ('I'd like to have that'), active resistance ('I'm not very keen') and passive resistance (minimal or no response). Cognitive test scores, prescription rates and satisfaction were assessed and associations were explored.

RESULTS

Doctors used suggestions in 42% of meetings, proposals in 25%, assertions in 13%, pronouncements in 11% and offers in 9%. Over 80% of patients did not indicate clear acceptance. Patients were most likely to actively resist after suggestions. There was no association between cognitive impairment and recommendation format. Patients were less satisfied with pronouncements. Patient preference did not influence whether medication was prescribed.

CONCLUSIONS

Doctors initially nominate people with dementia as the decision maker, and this is unaffected by cognitive impairment. Over 80% of patients resisted starting medication, mostly through passive resistance, the most common form of disagreement in communication. Medication still tended to be prescribed, indicating that factors other than patient preference affect prescription.Declarations of interestNone.

Prevalence of attention deficit hyperactivity disorder symptoms in patients with schizophrenia

OBJECTIVE

To investigate the frequency of childhood and adult attention deficit hyperactivity disorder (ADHD) symptoms in a cohort of patients with schizophrenia (SCZ).

METHODS

A systematic review was conducted to evaluate existing evidence. Two self-report questionnaires were used to investigate adult ADHD and childhood ADHD symptoms in 126 patients with ICD-10 diagnoses of SCZ.

RESULTS

Five studies were included in the systematic review, with the prevalence of childhood and adult ADHD in SCZ subjects ranging between 17-57% and 10-47% respectively. Within our cohort, 47% of patients reported positive screening for ADHD symptoms either in childhood or adulthood. 23% reported symptomatology consistent with both childhood and adult ADHD.

CONCLUSIONS

We demonstrate a greater presence of ADHD symptomatology in SCZ compared to that reported for ADHD in the general population. Our findings highlight the importance of improved clinical assessment and treatment considerations in a subgroup of patients with SCZ.

Delineating the psychiatric and behavioral phenotype of recurrent 2q13 deletions and duplications

Recurrent deletions and duplications at the 2q13 locus have been associated with developmental delay (DD) and dysmorphisms. We aimed to undertake detailed clinical characterization of individuals with 2q13 copy number variations (CNVs), with a focus on behavioral and psychiatric phenotypes. Participants were recruited via the Unique chromosomal disorder support group, U.K. National Health Service Regional Genetics Centres, and the DatabasE of genomiC varIation and Phenotype in Humans using Ensembl Resources (DECIPHER) database. A review of published 2q13 patient case reports was undertaken to enable combined phenotypic analysis. We present a new case series of 2q13 CNV carriers (21 deletion, 4 duplication) and the largest ever combined analysis with data from published studies, making a total of 54 deletion and 23 duplication carriers. DD/intellectual disabilities was identified in the majority of carriers (79% deletion, 70% duplication), although in the new cases 52% had an IQ in the borderline or normal range. Despite the median age of the new cases being only 9 years, 64% had a clinical psychiatric diagnosis. Combined analysis found attention deficit hyperactivity disorder (ADHD) to be the most frequent diagnosis (48% deletion, 60% duplication), followed by autism spectrum disorders (33% deletion, 17% duplication). Aggressive (33%) and self-injurious behaviors (33%) were also identified in the new cases. CNVs at 2q13 are typically associated with DD with mildly impaired intelligence, and a high rate of childhood psychiatric diagnoses-particularly ADHD. We have further characterized the clinical phenotype related to imbalances of the 2q13 region and identified it as a region of interest for the neurobiological investigation of ADHD.

Neurodevelopmental risk copy number variants in adults with intellectual disabilities and comorbid psychiatric disorders

BACKGROUND

Copy number variants (CNVs) are established risk factors for neurodevelopmental disorders. To date the study of CNVs in psychiatric illness has focused on single disorder populations. The role of CNVs in individuals with intellectual disabilities and psychiatric comorbidities are less well characterised.AimsTo determine the type and frequency of CNVs in adults with intellectual disabilities and comorbid psychiatric disorders.

METHOD

A chromosomal microarray analysis of 599 adults recruited from intellectual disabilities psychiatry services at three European sites.

RESULTS

The yield of pathogenic CNVs was high - 13%. Focusing on established neurodevelopmental disorder risk loci we find a significantly higher frequency in individuals with intellectual disabilities and comorbid psychiatric disorder (10%) compared with healthy controls (1.2%, P<0.0001), schizophrenia (3.1%, P<0.0001) and intellectual disability/autism spectrum disorder (6.5%, P < 0.00084) populations.

CONCLUSIONS

In the largest sample of adults with intellectual disabilities and comorbid psychiatric disorders to date, we find a high rate of pathogenic CNVs. This has clinical implications for the use of genetic investigations in intellectual disability psychiatry.Declaration of interestNone.

How do doctors deliver a diagnosis of dementia in memory clinics?

BACKGROUND

Dementia diagnosis rates are increasing. Guidelines recommend that people with dementia should be told their diagnosis clearly and honestly to facilitate future planning. Aims To analyse how doctors deliver a dementia diagnosis in practice.

METHOD

Conversation analysis was conducted on 81 video-recorded diagnosis feedback meetings with 20 doctors from nine UK memory clinics.

RESULTS

All doctors named dementia; 59% (n = 48) approached the diagnosis indirectly but delicately ('this is dementia') and 41% (n = 33) approached this directly but bluntly ('you have Alzheimer's disease'). Direct approaches were used more often with people with lower cognitive test scores. Doctors emphasised that the dementia was mild and tended to downplay its progression, with some avoiding discussing prognosis altogether.

CONCLUSIONS

Doctors are naming dementia to patients. Direct approaches reflect attempts to ensure clear diagnosis. Downplaying and avoiding prognosis demonstrates concerns about preserving hope but may compromise understanding about and planning for the future. Declaration of interest None.

Genetic testing in intellectual disability psychiatry: Opinions and practices of UK child and intellectual disability psychiatrists

Background

An increasing number of genetic causes of intellectual disabilities (ID) are identifiable by clinical genetic testing, offering the prospect of bespoke patient management. However, little is known about the practices of psychiatrists and their views on genetic testing.

Method

We undertook an online survey of 215 psychiatrists, who were contacted via the Royal College of Psychiatrist's Child and Adolescent and Intellectual Disability Psychiatry mailing lists.

Results

In comparison with child and adolescent psychiatrists, intellectual disability psychiatrists ordered more genetic tests, referred more patients to genetic services, and were overall more confident in the genetic testing process. Respondents tended to agree that genetic diagnoses can help patient management; however, management changes were infrequently found in clinical practice.

Conclusions

Differences are apparent in the existing views and practices of child and adolescent and intellectual disability psychiatrists. Developing training and collaboration with colleagues working in genetic services could help to reduce discrepancies and improve clinical practice.

Cortical venous disease severity in MELAS syndrome correlates with brain lesion development

PURPOSE

MELAS syndrome is a mitochondrial disorder typified by recurrent stroke-like episodes, seizures, and progressive brain injury. Abnormal mitochondria have been found in arterial walls implicating a vasculogenic etiology. We have observed abnormal cortical vein T2/FLAIR signal in MELAS patients, potentially representing wall thickening and sluggish flow. We sought to examine the relationship of hyperintense veins and brain lesions in MELAS.

METHODS

Imaging databases at two children's hospitals were searched for brain MRIs from MELAS patients. Artifact, sedated exams, and lack of 2D-T2/FLAIR sequences were exclusion criteria. Each exam was assigned a venous score based on number of T2/FLAIR hyperintense veins: 1 = <10, 2 = 10 to 20, 3 = >20. Cumulative brain lesions and venous score in MELAS and aged-matched normal exams were compared by Mann-Whitney test.

RESULTS

A total of 106 exams from 14 unique MELAS patients (mean 16 ± 3 years) and 30 exams from normal aged-matched patients (mean 15 ± 3 years) were evaluated. Median venous score between MELAS and control patients significantly differed (3 versus 1; p < 0.001). In the MELAS group, venous score correlated with presence (median = 3) or absence (median = 1) of cumulative brain lesions. In all 8 MELAS patients who developed lesions, venous hyperintensity was present prior to, during, and after lesion onset. Venous score did not correlate with brain lesion acuity.

CONCLUSION

Abnormal venous signal correlates with cumulative brain lesion severity in MELAS syndrome. Cortical venous stenosis, congestion, and venous ischemia may be mechanisms of brain injury. Identification of cortical venous pathology may aid in diagnosis and could be predictive of lesion development.

An integrated genetic-epigenetic analysis of schizophrenia: evidence for co-localization of genetic associations and differential DNA methylation

BACKGROUND

Schizophrenia is a highly heritable, neuropsychiatric disorder characterized by episodic psychosis and altered cognitive function. Despite success in identifying genetic variants associated with schizophrenia, there remains uncertainty about the causal genes involved in disease pathogenesis and how their function is regulated.

RESULTS

We performed a multi-stage epigenome-wide association study, quantifying genome-wide patterns of DNA methylation in a total of 1714 individuals from three independent sample cohorts. We have identified multiple differentially methylated positions and regions consistently associated with schizophrenia across the three cohorts; these effects are independent of important confounders such as smoking. We also show that epigenetic variation at multiple loci across the genome contributes to the polygenic nature of schizophrenia. Finally, we show how DNA methylation quantitative trait loci in combination with Bayesian co-localization analyses can be used to annotate extended genomic regions nominated by studies of schizophrenia, and to identify potential regulatory variation causally involved in disease.

CONCLUSIONS

This study represents the first systematic integrated analysis of genetic and epigenetic variation in schizophrenia, introducing a methodological approach that can be used to inform epigenome-wide association study analyses of other complex traits and diseases. We demonstrate the utility of using a polygenic risk score to identify molecular variation associated with etiological variation, and of using DNA methylation quantitative trait loci to refine the functional and regulatory variation associated with schizophrenia risk variants. Finally, we present strong evidence for the co-localization of genetic associations for schizophrenia and differential DNA methylation.

Dementia diagnostic criteria in Down syndrome

OBJECTIVE

Dementia is a common clinical presentation among older adults with Down syndrome. The presentation of dementia in Down syndrome differs compared with typical Alzheimer's disease. The performance of manualised dementia criteria in the International Classification of Diseases (ICD)-10 and Diagnostic and Statistical Manual of Mental Disorders-IV-Text Revision (DSM-IV-TR) is uncertain in this population.We aimed to determine the concurrent validity and reliability of clinicians' diagnoses of dementia against ICD-10 and DSM-IV-TR diagnoses. Validity of clinical diagnoses were also explored by establishing the stability of diagnoses over time.

METHODS

We used clinical data from memory assessments of 85 people with Down syndrome, of whom 64 (75.3%) had a diagnosis of dementia. The cases of dementia were presented to expert raters who rated the case as dementia or no dementia using ICD-10 and DSM-IV-TR criteria and their own clinical judgement.

RESULTS

We found that clinician's judgement corresponded best with clinically diagnosed cases of dementia, identifying 84.4% cases of clinically diagnosed dementia at the time of diagnosis. ICD-10 criteria identified 70.3% cases, and DSM-IV-TR criteria identified 56.3% cases at the time of clinically diagnosed dementia. Over time, the proportion of cases meeting ICD-10 or DSM-IV-TR diagnoses increased, suggesting that experienced clinicians used their clinical knowledge of dementia presentation in Down syndrome to diagnose the disorder at an earlier stage than would have been possible had they relied on the classic description contained in the diagnostic systems.

CONCLUSIONS

Clinical diagnosis of dementia in Down syndrome is valid and reliable and can be used as the standard against which new criteria such as the DSM-5 are measured.

Use of interactive teaching techniques to introduce mental health training to medical schools in a resource poor setting

OBJECTIVE

There are currently no practising psychiatrists in Somaliland. In 2007 the first medical students graduated from universities in Somaliland without mental health training. We aimed to pilot an intensive but flexible package of mental health training to all senior medical students and interns using interactive training techniques and to evaluate its effectiveness by assessing knowledge, skills and attitudes.

METHODS

Teaching techniques included didactic lectures, case based discussion groups and role playing. Informal feedback informed a flexible teaching package. Assessment tools designed specifically for this course included a pre and post course MCQ exam and an OSCE. Changes in students' attitudes were evaluated using a questionnaire administered before and after the course. In addition, a questionnaire administered following the course evaluated the changes students perceived in their knowledge and attitudes to mental health.

RESULTS

The MCQ improved from 50.7% pre course to 64.4% post course (p = 9.73 E-08). Students achieved an average overall OSCE mark of 71%. The pre and post attitudes questionnaire was most significantly different for statements relevant to aetiology, stigma and the overlap between mental and physical health. The statement most strongly agreed with after the course was 'I now understand more about the overlap between mental and physical health'.

CONCLUSION

Interactive teaching provided a learning experience for both students and trainers. On site and distance learning based on the teaching described here has widened the scope of the training possible in psychiatry and allowed the provision of regular teaching, supervision and peer support in Somaliland. However, the current lack of local expertise means that important issues of sustainability need to be considered in future work.

Polygenic dissection of the bipolar phenotype

BACKGROUND

Recent data provide strong support for a substantial common polygenic contribution (i.e. many alleles each of small effect) to genetic susceptibility for schizophrenia and overlapping susceptibility for bipolar disorder.

AIMS

To test hypotheses about the relationship between schizophrenia and psychotic types of bipolar disorder.

METHOD

Using a polygenic score analysis to test whether schizophrenia polygenic risk alleles, en masse, significantly discriminate between individuals with bipolar disorder with and without psychotic features. The primary sample included 1829 participants with bipolar disorder and the replication sample comprised 506 people with bipolar disorder.

RESULTS

The subset of participants with Research Diagnostic Criteria schizoaffective bipolar disorder (n = 277) were significantly discriminated from the remaining participants with bipolar disorder (n = 1552) in both the primary (P = 0.00059) and the replication data-sets (P = 0.0070). In contrast, those with psychotic bipolar disorder as a whole were not significantly different from those with non-psychotic bipolar disorder in either data-set.

CONCLUSIONS

Genetic susceptibility influences at least two major domains of psychopathological variation in the schizophrenia-bipolar disorder clinical spectrum: one that relates to expression of a 'bipolar disorder-like' phenotype and one that is associated with expression of 'schizophrenia-like' psychotic symptoms.

Genome-wide association study of suicide attempts in mood disorder patients

OBJECTIVE

Family and twin studies suggest that liability for suicide attempts is heritable and distinct from mood disorder susceptibility. The authors therefore examined the association between common genomewide variation and lifetime suicide attempts.

METHOD

The authors analyzed data on lifetime suicide attempts from genomewide association studies of bipolar I and II disorder as well as major depressive disorder. Bipolar disorder subjects were drawn from the Systematic Treatment Enhancement Program for Bipolar Disorder cohort, the Wellcome Trust Case Control Consortium bipolar cohort, and the University College London cohort. Replication was pursued in the NIMH Genetic Association Information Network bipolar disorder project and a German clinical cohort. Depression subjects were drawn from the Sequential Treatment Alternatives to Relieve Depression cohort, with replication in the Netherlands Study of Depression and Anxiety/Netherlands Twin Register depression cohort.

RESULTS

Strongest evidence of association for suicide attempt in bipolar disorder was observed in a region without identified genes (rs1466846); five loci also showed suggestive evidence of association. In major depression, strongest evidence of association was observed for a single nucleotide polymorphism in ABI3BP, with six loci also showing suggestive association. Replication cohorts did not provide further support for these loci. However, meta-analysis incorporating approximately 8,700 mood disorder subjects identified four additional regions that met the threshold for suggestive association, including the locus containing the gene coding for protein kinase C-epsilon, previously implicated in models of mood and anxiety.

CONCLUSIONS

The results suggest that inherited risk for suicide among mood disorder patients is unlikely to be the result of individual common variants of large effect. They nonetheless provide suggestive evidence for multiple loci, which merit further investigation.

DISC1 association, heterogeneity and interplay in schizophrenia and bipolar disorder

Disrupted in schizophrenia 1 (DISC1) has been associated with risk of schizophrenia, schizoaffective disorder, bipolar disorder, major depression, autism and Asperger syndrome, but apart from in the original translocation family, true causal variants have yet to be confirmed. Here we report a harmonized association study for DISC1 in European cohorts of schizophrenia and bipolar disorder. We identify regions of significant association, demonstrate allele frequency heterogeneity and provide preliminary evidence for modifying interplay between variants. Whereas no associations survived permutation analysis in the combined data set, significant corrected associations were observed for bipolar disorder at rs1538979 in the Finnish cohorts (uncorrected P=0.00020; corrected P=0.016; odds ratio=2.73+/-95% confidence interval (CI) 1.42-5.27) and at rs821577 in the London cohort (uncorrected P=0.00070; corrected P=0.040; odds ratio=1.64+/-95% CI 1.23-2.19). The rs821577 single nucleotide polymorphism (SNP) showed evidence for increased risk within the combined European cohorts (odds ratio=1.27+/-95% CI 1.07-1.51), even though significant corrected association was not detected (uncorrected P=0.0058; corrected P=0.28). After conditioning the European data set on the two risk alleles, reanalysis revealed a third significant SNP association (uncorrected P=0.00050; corrected P=0.025). This SNP showed evidence for interplay, either increasing or decreasing risk, dependent upon the presence or absence of rs1538979 or rs821577. These findings provide further support for the role of DISC1 in psychiatric illness and demonstrate the presence of locus heterogeneity, with the effect that clinically relevant genetic variants may go undetected by standard analysis of combined cohorts.

A genomewide association study of response to lithium for prevention of recurrence in bipolar disorder

OBJECTIVE

Lithium remains a first-line treatment for bipolar disorder, but the mechanisms by which it prevents the recurrence of mood episodes are not known. The authors utilized data from a genomewide association study to examine associations between single nucleotide polymorphisms (SNPs) and the outcome of lithium treatment in two cohorts of patients with bipolar I disorder or bipolar II disorder.

METHOD

The hazard for mood episode recurrence was examined among 1,177 patients with bipolar I disorder or bipolar II disorder, including 458 individuals treated with lithium carbonate or citrate, who were participants in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) cohort. SNPs showing the greatest evidence of association in Cox regression models were then examined for association with positive lithium response among 359 bipolar I or II disorder patients treated with lithium carbonate or citrate in a second cohort from the University College London.

RESULTS

The strongest association in the STEP-BD cohort (minimum p=5.5 x 10(-7)) was identified for a region on chromosome 10p15 (rs10795189). Of the regions showing suggestive evidence (p<5 x 10(-4)) of association with lithium response, five were further associated with positive lithium response in the University College London cohort, including SNPs in a region on chromosome 4q32 spanning a gene coding for the glutamate/alpha-amino-3-hydroxy-5-methyl-4-isoxazolpropionate (AMPA) receptor GRIA2.

CONCLUSIONS

Multiple novel loci merit further examination for association with lithium response in bipolar disorder patients, including one region that spans the GRIA2 gene, for which expression has been shown to be regulated by lithium treatment.

Relationship of primary mitochondrial respiratory chain dysfunction to fiber type abnormalities in skeletal muscle

Variation in the size and relative proportion of type 1 and type 2 muscle fibers can occur in a number of conditions, including structural myopathies, neuropathies, and various syndromes. In most cases, the pathogenesis of such fiber type changes is unknown and the etiology is heterogeneous. Skeletal muscle mitochondrial respiratory chain analysis was performed in 10 children aged 3 weeks to 5 years with abnormalities in muscle fiber type, size, and proportion. Five children were classified as having definite, four as probable, and one as possible mitochondrial disease. Type 1 fiber predominance was the most common histological finding (six of 10). On light microscopy, four cases had subtle concomitants of a mitochondriopathy, including mildly increased glycogen, lipid, and/or succinate dehydrogenase staining, and one case had more prominent evidence of underlying mitochondrial disease with marked subsarcolemmal staining. Most cases (nine of 10) had abnormal mitochondrial morphology on electron microscopy. All were found to have mitochondrial electron transport chain (ETC) abnormalities and met diagnostic criteria for mitochondrial disease. We did not ascertain any patients who had isolated fiber type abnormalities and normal respiratory chain analysis during the period of study. We conclude that mitochondrial ETC disorders may represent an etiology of at least a subset of muscle fiber type abnormalities. To establish an etiologic diagnosis and to determine the frequency of such changes in mitochondrial disease, we suggest analysis of ETC function in individuals with fiber type changes in skeletal muscle, even in the absence of light histological features suggestive of mitochondrial disorders.

Grepafloxacin pharmacokinetics in individuals with hepatic dysfunction

The pharmacokinetics of grepafloxacin, a new broad spectrum fluoroquinolone antibiotic, were studied in 2 trials involving 14 healthy volunteers, 10 individuals with mild (Child-Pugh Class A) impairment of liver function, and 12 with moderate (Child-Pugh Class B or C) hepatic impairment. All participants received an oral dose of grepafloxacin 400 mg, daily for 7 days, and plasma and urine grepafloxacin concentrations were measured over 7 days. The pooled data from participants with impaired liver function showed that, compared with healthy individuals, peak plasma grepafloxacin concentrations, area under the plasma concentration-time curve and proportion of the dose excreted in the urine were increased. In addition, apparent total clearance was reduced in the presence of hepatic dysfunction. Peak concentrations were increased by 36% and 48% in individuals with Class A and B disease, respectively; the corresponding reductions in clearance were 33% and 55%, respectively. Child-Pugh scores and components of the scores showed no correlation with any pharmacokinetic variables. Based on these findings, we recommend a daily grepafloxacin dose of 400 mg in patients with mild hepatic impairment, irrespective of the severity of infection. Grepafloxacin should not be used in patients with moderate or severe liver disease.

Raccoon roundworm (Baylisascaris procyonis) encephalitis: case report and field investigation

Baylisascaris procyonis is a common and widespread parasite of raccoons in the United States and Canada. With large raccoon populations occurring in many areas, the potential risk of human infection with B procyonis is high. We report a case of severe raccoon roundworm (B procyonis) encephalitis in a young child to illustrate the unique clinical, diagnostic, and treatment aspects, as well as public health concerns of B procyonis infection. Acute and convalescent serum and cerebrospinal fluid samples from the patient were tested for antibodies against B procyonis to assist in documenting infection. An extensive field survey of the patient's residence and the surrounding community was performed to investigate raccoon abundance and to determine the extent of raccoon fecal contamination and B procyonis eggs in the environment. The patient evidenced serologic conversion, and the field investigation demonstrated a raccoon population far in excess of anything previously reported. There was abundant evidence of B procyonis eggs associated with numerous sites of raccoon defecation around the patient's residence and elsewhere in the community. Because B procyonis can produce such severe central nervous system disease in young children, it is important that pediatricians are familiar with this infection. The public should be made aware of the hazards associated with raccoons and B procyonis to hopefully prevent future cases of B procyonis infection.

Evidence for a locally driven mucosal response and the presence of mitochondrial antigens in saliva in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is often considered to be a dry gland disease caused by frequent involvement of salivary and lacrimal glands. Although high titers of antimitochondrial autoantibodies (AMA) have long been recognized in PBC, little is known about the presence of mitochondrial autoantigens in mucosal compartments such as saliva. We investigated saliva and sera in PBC patients and controls for the presence of AMA and mitochondrial antigens. In PBC saliva, AMA were detected in 45 of 49 (92%), with specificity directed against pyruvate dehydrogenase complex (PDC-E2) alone in 22 of 49 (45%), against PDC-E2 and branched-chain 2-oxo-acid dehydrogenase complex E2 (BCOADC-E2) in 4 of 49 (8%), to PDC-E2 and 2-oxoglutarate dehydrogenase complex E2 (OGDC-E2) in 9 of 49 (18%), and to the 3 antigens together in 10 of 49 (20%). Isotyping of the saliva AMA showed that 80% of the patients had immunoglobulin A (IgA) against PDC-E2, 18% had IgM-specific PDC-E2, and 35% had IgG specific PDC-E2. Similar to serum and bile anti-PDC-E2 IgA antibodies, the saliva autoantibodies localized their reactivity to the inner lipoyl domain of PDC-E2. Furthermore, saliva from patients with PBC but not controls inhibited pyruvate dehydrogenase enzyme activity in vitro. In addition, and of particular interest, we detected a molecule with a molecular weight corresponding to PDC-E2 (74 kd) in PBC but not control saliva. These findings make several important points: first, there appears to be localized mucosal immunity in the secretory system of PBC; second, AMA are readily detected in PBC saliva; and third, PDC-E2 may be present in the saliva of PBC.

Cerebral palsy and neurodegenerative disease

Cerebral palsy refers to a neurologic disorder of motor skills that is static in nature and is the result of injury to the brain before its development is complete. Many neurodegenerative or metabolic disorders have a slow rate of progression and can be misdiagnosed as cerebral palsy. Diseases that have been misdiagnosed as cerebral palsy are presented here to provide the clinician with framework for the complex evaluation of these patients.

Evidence for linkage to psychosis and cerebral asymmetry (relative hand skill) on the X chromosome

The hypothesis that psychosis arises as a part of the genetic diversity associated with the evolution of language generates the prediction that illness will be linked to a gene determining cerebral asymmetry, which, from the evidence of sex chromosome aneuploidies, is present in homologous form on the X and Y chromosomes. We investigated evidence of linkage to markers on the X chromosome in 1) 178 families multiply affected with schizophrenia or schizoaffective disorder with a series of 16 markers spanning the centromere (study 1), and 2) 180 pairs of left-handed brothers with 14 markers spanning the whole chromosome (study 2). In study 1, excess allele-sharing was observed in brother-brother pairs (but not brother-sister or a small sample of sister-sister pairs) over a region of approximately 20 cM, with a maximum LOD score of 1.5 at DXS991. In study 2, an association between allele-sharing and degree of left-handedness was observed extending over approximately 60 cM, with a maximum lod score of 2.8 at DXS990 (approximately 20 cM from DXS991). Within the overlap of allele-sharing is located a block in Xq21 that transposed to the Y chromosome in recent hominid evolution and is now represented as two segments on Yp. In one of two XX males with psychosis we found that the breakpoint on the Y is located within the distal region of homology to the block in Xq21. These findings are consistent with the hypothesis that an X-Y homologous determinant of cerebral asymmetry carries the variation that contributes to the predisposition to psychotic illness.

Imaging patterns of neonatal hypoglycemia

PURPOSE

Our purpose was to report the patterns of injury observed in five patients who suffered brain damage consequent to neonatal hypoglycemia.

METHODS

The imaging studies and clinical records of five patients with brain damage caused by neonatal hypoglycemia were reviewed retrospectively. Patterns of injury were compared with those described in the literature and those seen in neonatal hypoxic-ischemic injury.

RESULTS

Diffuse cortical and subcortical white matter damage was seen, with the parietal and occipital lobes affected most severely. Globus pallidus injury was present in one patient who had the most severe cortical injury.

CONCLUSION

We found a specific pattern of injury that correlates well with the sparse pathologic and imaging reports on neonatal hypoglycemia. We speculate that the patterns of damage are the result of regional hypoperfusion and excitatory toxicity with cell-type-specific injury.

Involvement of the pontomedullary corticospinal tracts: a useful finding in the diagnosis of X-linked adrenoleukodystrophy

PURPOSE

To determine whether pontomedullary corticospinal tract involvement is a common and specific finding of adrenoleukodystrophy on MR images.

METHODS

MR images of 10 patients with biochemically proved adrenoleukodystrophy who were examined during the last 6 years were reviewed retrospectively to determine the frequency of corticospinal tract involvement in the medulla, pons, mesencephalon, internal capsules, and corona radiata. MR images of 10 patients with other leukodystrophies (three with Krabbe disease, two with Alexander disease, two with metachromatic leukodystrophy, two with Pelizaeus-Merzbacher disease, and one with Canavan disease) were reviewed with specific attention to the pontomedullary corticospinal tracts.

RESULTS

Medullary and pontine corticospinal tract involvement was present in eight of the 10 patients with adrenoleukodystrophy. Mesencephalic and internal capsular involvement was present in three patients. The coronal radiata portion of the corticospinal tracts was not involved in any of the 10 patients. No pontomedullary corticospinal tract involvement was identified in any of the 10 patients with other leukodystrophies. The difference in the frequency of pontomedullary corticospinal tract involvement between the two groups was highly significant.

CONCLUSION

Pontomedullary corticospinal tract involvement is a common finding in adrenoleukodystrophy and is unusual in other leukodystrophies. Awareness of this finding can facilitate the radiologic diagnosis of this disease and may expedite management of affected patients.

Assessment of noninvasive lower extremity arterial testing versus pulse exam

Palpation of pedal pulses was compared to noninvasive testing in 100 patients referred to a vascular laboratory. Subjects were 65 +/- 13 (mean +/- s.d.) years old. The right dorsalis pedis (DP) artery served as the reference artery for comparison of Doppler studies with physical examination of the pulses. Absolute Doppler pressures in the right DP were 129 +/- 50 mm Hg. The right ankle:brachial index (ABI) was 0.86 +/- 0.32. There were significant differences in ABI in those with (0.68 +/- 0.28) vs without (0.95 +/- 0.31) claudication in either extremity (p < 0.001). Rest pain was also associated with lower ABI (P < 0.04). Diabetics, hypertensives, claudicants and those with ischemic rest pain were less likely to have palpable pulses (P < 0.035). With right DP pressure >/= 118 mm Hg, 63 per cent of subjects had a palpable DP pulse, whereas 68 per cent with ABI > 0.82 had a palpable right DP. Of those (n = 35) with a right DP pressure < 118 mm Hg, only 6 per cent (n = 2) had a palpable pulse, whereas 5 per cent (2/40) with ABI </= 0.82 had palpable DP pulses. Based on these findings, it was predicted that a pulse would likely not be palpable in the left DP with a pressure < 118 mm Hg or with AB </= 0.82. The prediction based on systolic ankle pressures was correct, with 66 per cent sensitivity and 91 per cent specificity. The predication that a left DP pulse would not be palpable with AB </= 0.82 was more accurate (78% sensitive, 97% specific). Presence of a palpable DP pulse suggests the presence of a Doppler pressure >/= 188 mm Hg and ABI > 0.82. The range of ankle pressures with palpable right DP pulses was 64-220 mm Hg, whereas the range with nonpalpable DP was 42-300 mm Hg. Given the frequent disparity of pulse exam and ankle pressures, noninvasive Doppler testing may be necessary for many patients to accurately assess the vascular status of the leg.

Failure to find a chromosome 18 pericentric linkage in families with schizophrenia

A recent report of a possible linkage of bipolar affective disorder to a pericentric region of chromosome 18 initiated the present investigation to search for a similar linkage in 32 families with schizophrenia. The results of a study using 5 markers mapped to this region show negative lod scores and only weak evidence for any linkage by nonparametric analyses. If the previously reported finding is a true positive linkage for bipolar disorder, then either it is unlikely to be related to the genetics of schizophrenia, or the proportion of families linked to this region is small.

Supplementary sensorimotor area seizures in children and adolescents

RATIONALE

Some types of seizures in children may be difficult to recognize; the diagnosis of seizures arising near the mesial posterior frontal supplementary sensorimotor area (SSMA) may be especially challenging. Such seizures have been well described in adults, but few pediatric cases have been reported even though onset is typically in childhood.

METHODS

We studied 11 children and adolescents with SSMA seizures diagnosed by prolonged video electroencephalography (EEG).

RESULTS

Mean age at onset was 5.8 years, and diagnosis by video EEG was made at a mean age of 12 years. Children had at least borderline intelligence and few abnormal findings on neurologic examination. Seizures were typically brief, frequent, and predominantly nocturnal, with bilateral tonic posturing, gross proximal limb movements, and preserved consciousness. Magnetic resonance imaging showed normal findings or a superior or mesial posterior frontal tumor or cortical dysplasia. Routine EEG findings were usually normal, but prolonged EEG showed epileptiform discharges over the vertex. Seizure onset in the region of the SSMA was confirmed by subdural EEG in six patients who were studied for epilepsy surgery. Five patients had seizure-free outcome or worthwhile improvement after operation. Two nonoperated patients are seizure-free on antiepileptic medication, and three are undergoing surgical evaluation.

CONCLUSIONS

Diagnosis of SSMA seizures in children may be challenging because of unusual symptoms (bilateral tonic limb involvement with preserved consciousness) and frequently normal routine EEG findings. Video EEG may be necessary for diagnosis, and magnetic resonance imaging may reveal a focal lesion. Increased recognition of this seizure type in pediatric patients should lead to earlier diagnosis for optimal medical or surgical treatment.

Affective illness and schizophrenia in families with multiple schizophrenic members: independent illnesses or variant gene(s)?

Affective disorder occurs in some families with schizophrenia, and schizophrenic patients often describe concurrent episode(s) of depression that may lead them to be diagnosed schizoaffective. The present study examines the pattern of affective disorder in families with two or more members with schizophrenia or schizoaffective disorder. We find that affective disorders are more frequently inherited from the same parental side of the family as schizophrenia-like psychosis. When unipolar, it more often is expressed in female than male relatives (particularly mothers), and when bipolar it is more likely in males. In contrast, schizophrenia with and without depression is equally prevalent in both sexes. Unipolar illness was more common in relatives of schizophrenics whose illnesses are characterized by recurrent episodes of depression than in those whose are not. These data are consistent with the hypothesis that the same genes could contribute to susceptibility to both schizophrenia and affective disorder in some families, and that sex and phenotypic expression are in some way related. However, the phenomenon of high rates of depression in mothers of schizophrenic patients needs explanation.

Doppler echocardiography and the early diagnosis of carditis in acute rheumatic fever

BACKGROUND

The incidence of acute rheumatic fever in New Zealand remains relatively high. Reliable early diagnosis of carditis is difficult and important in management.

AIM

To determine if Doppler echocardiography contributed to the early diagnosis of carditis in acute rheumatic fever.

METHODS

Forty-seven patients admitted to hospital with suspected acute rheumatic fever and 19 control patients, with a febrile illness due to a documented non-cardiac bacterial infection, were assessed two days and two weeks following admission. Presence or absence of clinical carditis was determined by a cardiologist unaware of the suspected diagnosis, from clinical examination, chest radiograph, electrocardiogram (ECG) and two dimensional echocardiogram. Doppler echocardiography was then performed and interpreted by a second cardiologist unaware of the diagnosis. After completion of the study the Jones criteria were applied, to categorise the patients with suspected acute rheumatic fever into four groups for the final diagnosis: no acute rheumatic fever, possible acute rheumatic fever, definite acute rheumatic fever without carditis, and definite acute rheumatic fever with carditis.

RESULTS

In 19 patients with a final diagnosis of acute rheumatic fever and carditis at the baseline assessment carditis was detected by clinical assessment in 15 patients, compared with 19 patients with evidence of significant valve regurgitation by Doppler echocardiography. Following the two week assessment, all 19 patients had both clinical and Doppler evidence of carditis. Five patients with a final clinical diagnosis of possible acute rheumatic fever or definite acute rheumatic fever without carditis, had a Doppler abnormality detected. There was no clinical or Doppler abnormality in the febrile controls.

CONCLUSIONS

Doppler echocardiography is more sensitive than clinical assessment in the detection of carditis in acute rheumatic fever, and can contribute to earlier diagnosis.

Lipopeliosis. An immunohistochemical and clinicopathologic study of five cases

Lipopeliosis is an unusual liver lesion in which sinusoids become engorged by fat globules. It arises in newly transplanted donor livers that display varying degrees of fatty change. If, after transplantation, hepatocyte necrosis secondary to ischemic or preservation injury occurs, the fat escaping the hepatocytes becomes sequestered in the sinusoidal spaces. We previously described this lesion in a case report; we now describe four more cases to define better the incidence, immunohistochemical features, and clinical spectrum. Of 101 transplanted livers, the lesion was noted in five of 28 (18%), with both preservation injury and mild to moderate fatty change present 1 week following transplantation. Factor VIII-related antigen, collagen IV immunoperoxidase, and oil red O stains confirmed the engorgement of sinusoids by fat droplets, and a stain for CD68-positive cells identified a macrophage reaction around the fat droplets. The patient in our original report developed severe graft dysfunction with residual scarring of the centrilobular zone. Two of the four additional cases had no residual side effects from the lipopeliosis; however, two cases were associated with loss of graft. We conclude that lipopeliosis may be fairly common (5% of transplants). Its clinical outcome can vary greatly and most probably depends on the extent of hepatocellular necrosis.

Search for linkage to schizophrenia on the X and Y chromosomes

Markers for X chromosome loci were used in linkage studies of a large group of small families (n = 126) with at least two schizophrenic members in one sibship. Based on the hypothesis that a gene for schizophrenia could be X-Y linked, with homologous loci on both X and Y, our analyses included all families regardless of the pattern of familial inheritance. Lod scores were computed with both standard X-linked and a novel X-Y model, and sib-pair analyses were performed for all markers examining the sharing of maternal alleles. Small positive lod scores were obtained for loci pericentromeric, from Xp11.4 to Xq12. Lod scores were also computed separately in families selected for evidence of maternal inheritance and absence of male to male transmission of psychosis. The lod score for linkage to the locus DXS7 reached a maximum of 1.83 at 0.08% recombination, assuming dominant inheritance on the X chromosome in these families (n = 34). Further investigation of the X-Y homologous gene hypothesis focussing on this region is warranted.