POS0088-PARE CHANGES IN PATIENT-REPORTED OUTCOME SCORES DURING COVID-19 PANDEMIC: DATA FROM THE ArthritisPower REGISTRY

Background

The COVID-19 pandemic causes concern among patients with autoimmune and rheumatic disease (ARD) due to increased risk of infection and heightened isolation from social distancing.1

Objectives

Examine how mean patient-reported outcome (PRO) scores for mental, social and physical health fluctuated after COVID-19 vaccine availability was widespread in US.

Methods

We conducted and reported on2 an initial analysis of January 2020 – April 2021 where US participants (pts) of the ArthritisPower (AP) registry completed PROMIS measures of physical health (Physical Function, Pain Interference, Fatigue, Sleep Disturbance), mental health (Anger, Anxiety, Depression) and social health (Social Isolation, Emotional Support). Follow-up analysis was conducted May – December 2021. Only pts from initial analysis were included in follow-up. Null hypothesis was no change in monthly average scores across 23-month pandemic period. Analysis of means compared monthly assessment mean scores to overall mean score for each measure during study period. Pts with < 2 assessment time points and osteoarthritis with no ARD were excluded from analysis.

Results

Total of 49,940 PRO scores were contributed by 2,266 pts during 23-month period, with 8,393 of the scores contributed from May – December 2021. Mean (standard deviation, SD) number of observations per pt was 5.6 (12.5). Pts were 87.6% female, 86.7% white, mean age of 52.1 (12.7) years. Rheumatoid arthritis (n=1,131, 49.9%) was the most common condition. Most commonly reported measures were Pain Interference, Fatigue, Sleep Disturbance and Physical Function, each with >11,000 total results (Table 1).

Table 1.

Avg assessment scores+ by month, mean (SD)

Pain Interf (n= 11536)Fatigue (n= 11591)Sleep Disturb (n= 11257)Physical Func (n= 11202)Depression (n=1489)Anxiety (n= 1066)Social Iso (n=698)Emot Support (n=578)Anger (n=523)Study Period^63.3 (7.8)62.6 (9.5)58.1 (9.0)37.7 (7.6)60.8 (9.2)62.4 (10.5)61.9 (10.2)40.8 (9.8)61.5 (12.8)May 202161.9 (8.2)*60.9 (9.7)*55.2 (8.8)*38.9 (8.5)59.5 (9.2)61.9 (9.8)60.2 (13.3)38.1 (8.3)59.6 (14.5)June61.6 (6.9)*60.9 (9.6)*54.8 (8.9)*38.3 (7.8)59.2 (7.0)60.6 (9.6)61.8 (12.0)39.3 (10.3)60.2 (10.9)July61.8 (7.4)*60.8 (10.2)*56.0 (8.6)*38.1 (7.9)61.0 (7.8)59.9 (12.1)66.8 (8.5)*39.4 (9.7)62.4 (9.7)Aug61.2 (8.5)*60.7 (10.4)*55.8 (9.6)*38.5 (8.5)57.7 (7.9)*58.2 (10.3)*57.2 (11.1)36.9 (12.2)53.3 (19.4)Sep62.4 (8.5)62.3 (10.0)56.2 (8.3)37.3 (7.6)58.7 (8.0)57.7 (11.3)*68.1 (12.8)36.7 (12.1)58.7 (12.0)Oct63.1 (8.4)63.3 (9.9)57.6 (8.6)37.3 (8.0)59.9 (9.9)62.3 (9.0)64.3 (10.3)37.3 (11.4)64.6 (10.2)Nov62.6 (6.8)63.2 (10.0)55.8 (8.6)*36.9 (7.0)59.1 (8.8)61.3 (6.8)61.4 (10.9)38.6 (11.7)60.3 (12.4)Dec62.9 (8.3)64.0 (9.6)56.5 (8.4)37.4 (8.1)60.7 (8.4)63.8 (5.3)65.1 (7.5)38.5 (13.5)68.6 (5.0)*

+PROMIS measures scored 0-100; mean 50 for general US population; 1SD = 10 points

^Study period: January 2020 – December 2021

. *Statistical significance (p<0.05); analysis of means (ANOM)

Pts’ mental and social health assessment scores improved then worsened during last 8 months of 2021 (Figure 1). Overall mean scores were: Anxiety 62.4 (12.5), Social Isolation 61.9 (10.5), and Anger 61.5 (12.8). From July – August, Social Isolation decreased by 1 SD. Compared to overall assessment mean, Anger declined by > ½ SD (53.3 [19.4]) in August and Anxiety declined by ½ SD (57.7 [11.3]) in September. By December, Anger rose by > ½ SD (68.6 [5.0]) of assessment mean. Pain Interference (mean: 63.3 [7.8]), Fatigue (62.6 [9.5]), and Sleep Disturbance (58.1 [9.0]) scores were significantly lower in May, June, July and August compared to the assessment mean, though none decreased by > ½ SD.

Conclusion

ARD members of AP had mental, social and physical health scores improve during summer of 2021, corresponding with widespread availability of vaccines. However mental and social health scores worsened by December as US faced new variants of the virus.

References

[1]George M, et al. Rheumatol. 2021;48:603-7.

[2]Gavigan K, et al. Arth Rheumatol. 2021;73(suppl 10).

Acknowledgements

This work was partially supported through a Patient-Centered Outcomes Research Institute (PCORI) award (PPRN-1306-04811). All statements in this poster, including its findings and conclusions, are solely those of the authors and do not necessarily represent the views of PCORI, its Board of Governors or Methodology Committee.

Disclosure of Interests

Kelly Gavigan: None declared, Esteban Rivera: None declared, Jeffrey R. Curtis Consultant of: Gilead, Novartis, and Samsung, Grant/research support from: AbbVie, Amgen, BMS, Corrona, Eli Lilly and Company, Janssen, Myriad, Pfizer, Regeneron, Roche, and UCB, Shilpa Venkatachalam: None declared, Laura Stradford: None declared, David Curtis: None declared, W. Benjamin Nowell Grant/research support from: William B. Nowell is the Principal Investigator on grants/contracts from AbbVie, Eli Lilly and Company, and PCORI, and an employee of the Global Healthy Living Foundation (GHLF). GHLF receives grants, sponsorships and contracts from pharmaceutical manufacturers and private foundations. A full list of GHLF funders is publicly available here: https://www.ghlf.org/our-partners/.

Clinical features of UK Biobank subjects carrying loss of function variants in genes implicated in schizophrenia pathogenesis

Introduction

The SCHEMA consortium has identified ten genes in which severely damaging variants substantially increase schizophrenia risk.

Objectives

To characterise the clinical features of carriers of variants causing complete loss of function (LOF) of these genes.

Methods

This research was conducted using the UK Biobank Resource and 200,000 exome-sequenced volunteers were screened to identify carriers of LOF variants in these genes. For these subjects, data fields were extracted which reflected educational and occupational functioning as well as clinical features including diagnoses and medication.

Results

LOF variants in CACNA1G were commoner than in SCHEMA cases, suggesting this was not a real schizophrenia susceptibility gene. 159 subjects carried LOF variants in one of the other nine genes and overall they did not have poorer educational or occupational functioning or increased mental or physical health problems. Detailed examination revealed that one had schizophrenia, one had psychotic depression and two had a developmental disorder. Otherwise, a number of subjects had features of minor mental illness such as depression or anxiety and these rates were somewhat increased in subjects carrying LOF variants in HERC1, of whom more than half reported having consulted their GP for such problems. However the majority appeared to be entirely normal from a neuropsychiatric point of view.

Conclusions

Although particular genetic variants can substantially increase the risk of schizophrenia, most people carrying them are entirely normal. This further supports the concept of schizophrenia as a distinct illness rather than representing the extreme of a trait which is present in the population.

Disclosure

No significant relationships.

Healthcare-associated infections and the prescribing of antibiotics in hospitalized patients of the Caribbean Community (CARICOM) states: a mixed-methods systematic review

BACKGROUND

Healthcare-associated infections (HCAIs) and variation in antibiotic prescribing pose a significant public health challenge in hospitals of low-resource countries.

AIM

To critically appraise and synthesize the evidence on HCAI and the prescribing of antibiotics in Caribbean Community (CARICOM) states.

METHODS

All primary qualitative and quantitative studies that addressed HCAI, and the prescribing of antibiotics in hospitalized patients of CARICOM states were included. Ovid Medline, Embase, Global Health, and regional databases were searched. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Findings were presented in narrative and table formats.

FINDINGS

Twenty-one studies met the inclusion criteria for this mixed-methods systematic review (MMSR). Studies were from four different CARICOM states: Trinidad and Tobago, Jamaica, Haiti, and Antigua and Barbuda. Intensive care units (ICUs) had the highest rate of infections (67% over four years). Surgical site infections were discussed by seven studies and ranged from 1.5% to 7.3%. For inpatients with contaminated or infected wounds, rates ranged from 29% to 83%. Empiric and prophylactic therapies were common and inappropriately prescribed. Resources and training for healthcare workers in infection control and antimicrobial stewardship were insufficient. Few qualitative studies existed, so it was not possible to integrate evidence from qualitative and quantitative paradigms.

CONCLUSION

Evidence from CARICOM states shows high rates of HCAI and inappropriately prescribed antibiotics, primarily in ICUs. Disease surveillance, infection control, and antimicrobial stewardship programmes require urgent evidence-based improvements.

Thermal Imaging of Root Caries In Vivo

Improved methods are needed to assess the structure and activity of lesions on root surfaces in order to improve clinical decision making. Conventional visual and tactile methods for assessing lesion activity are not reliable, and the clinician is often unable to evaluate if the lesion is progressing or has remineralized. An important marker of an arrested lesion is a highly mineralized surface zone that forms when mineral is deposited in the outer layer of the lesion. In vitro studies have shown that a mineralized surface zone influences the kinetics of water evaporation and the surface temperature while drying. Temperature changes can be monitored by measuring the thermal emission with thermal imaging. Studies have also shown that the depth and severity of demineralization and the thickness of the highly mineralized transparent surface zone on arrested lesions can be measured nondestructively with optical coherence tomography (OCT). Thermal imaging at 8-µm to 13-µm wavelengths was completed on 30 test subjects with a suspected active root caries lesion by monitoring thermal emission from the tooth surfaces during 30 s of air drying. Lesions were also evaluated using cross-polarization OCT (CP-OCT) during lesion dehydration to identify transparent surface zones indicative of arrested lesions and determine if shrinkage occurred during drying. The overall thermal emission recorded during drying was significantly different (P < 0.001) when comparing sound tooth surfaces, lesion areas identified as arrested, and lesion areas identified as active, demonstrating that thermal imaging is a promising approach for the clinical assessment of lesion activity on root surfaces. Ten of the lesions in this study had distinct areas with transparent surface zones that were visible in CP-OCT images. Shrinkage was detected with CP-OCT during drying for 12 lesions. This study confirms that these novel approaches for assessing lesion activity on root surfaces can be implemented in vivo.

THU0564 PARTICIPANT ENGAGEMENT IN AN ARTHRITISPOWER REAL-WORLD STUDY TO CAPTURE SMARTWATCH AND PATIENT-REPORTED OUTCOME DATA AMONG RHEUMATOID ARTHRITIS PATIENTS

Background:

Clear characterization of how different types of patient-generated data reflect patient experience is needed to guide integration of electronic patient-reported outcome (ePRO) measures and biometrics in generating real-word evidence (RWE) related to rheumatoid arthritis (RA).

Objectives:

To characterize the level of participant (pt) engagement/adherence and data completeness in an ongoing study of 250 RA pts enrolled in the Digital Tracking of Arthritis Longitudinally (DIGITAL) study1of the ArthritisPower real-world registry.

Methods:

ArthritisPower pts with RA were invited to join a digital RWE study with 14-day lead-in and 12-week main study period. In the lead-in, pts were required to electronically complete: a) two daily single-item Pain and Fatigue numeric rating scales and b) longer weekly sets of ePROs. Successful completers of the lead-in were mailed a smartwatch (Fitbit Versa) and study materials. The smartwatch collected activity, heart rate, and sleep duration/quality biosensor data; a study-specific customization of the ArthritisPower mobile application collected ePROs. The main study period included automated and manual reminders/prompts about completing ePROs, wearing the smartwatch and regularly syncing it. Study coordinators monitored pt data and contacted pts via email, text and/or phone to resolve adherence issues during the conduct of the study based on pre-determined rules triggering pt contact. Rules were based chiefly on consecutive spans of missing data. Pts were considered adherent in giving complete data for each week if providing (1) daily ePROs for ≥5 of 7 days/week, (2) weekly ePROs and (3) ≥80% of synced activity data for ≥5 of 7 days/week. Composite adherence for the first month of the main study period required meeting >70% weekly adherence parameters during the first 30 days, ie completing daily ePROs for ≥5 of 7 days/week, weekly ePROs ≥3 of 4 weeks and ≥80% of synced activity data for ≥5 of 7 days/week.

Results:

As of December 2019, 170 ArthritisPower members enrolled and completed at least 30 days of the main study period; 92.9% female with mean (SD) age 52.5 (10.7) and 10.5 (10.4) years since diagnosis. The overall conversion rate from initial interest to successful completion of the lead-in period was 49.0%. Pts who advanced to the main study were significantly more likely than those who did not to be currently employed (52.9% vs. 41.8%, p=0.038) and be on biologic DMARD monotherapy (64.7% vs. 47.5%, p=0.001). Overall, daily ePRO data had the lowest adherence with 70.0% of pts providing >70% of the requested data consistently across the first 30 days of the main study period (Figure 1). Composite adherence was met by 66.5% of pts. The most common time of day to provide ePRO data was morning, in the hours around scheduled app and email notifications at 10 a.m. in pt’s local time zone. Activity data had the highest adherence and persistence, with 92.9% of pts providing 80% or more of activity data for each 24-hour period in the first 30 days (Figures 1 & 2). Observed weekly adherence did not decline over time. Of 5100 possible person days in the study at day 30, we observed 643 days (91.0% of actual to maximum possible total patient days) where activity data was provided for at least 80% of the 24-hour period.

Conclusion:

RWE studies involving passive data collection in RA require pt-centric implementation and design to minimize pt burden, promote longitudinal engagement and maximize adherence. Passive data capture via activity trackers such as smartwatches, along with regular contact such as automated reminders, may facilitate greater pt adherence in providing longitudinal data for clinical trials.

References:

[1]Nowell WB, et al. JMIR Res Protoc. 2019;8(9):e14665.

Disclosure of Interests:

W. Benjamin Nowell: None declared, Jeffrey Curtis Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB, Fenglong Xie: None declared, Hong Zhao: None declared, David Curtis: None declared, Kelly Gavigan: None declared, Shilpa Venkatachalam: None declared, Laura Stradford: None declared, Jessica Boles: None declared, Justin Owensby: None declared, Cassie Clinton: None declared, Ilya Lipkovich Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Amy Calvin Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Virginia S. Haynes Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company

FRI0018 USING SELF-REPORTED OUTCOMES TO DETECT NEW-ONSET FLARE IN A REAL-WORLD STUDY OF PARTICIPANTS WITH RHEUMATOID ARTHRITIS - INTERIM RESULTS FROM THE DIGITAL TRACKING OF ARTHRITIS LONGITUDINALLY (DIGITAL) STUDY

Background:

Patients with rheumatoid arthritis (RA) experience fluctuating symptoms, increased pain, decreased function and variable quality of life; such changes often occur between visits to clinicians. Digital Tracking of Arthritis Longitudinally (DIGITAL) study2is evaluating the use of electronically captured patient-reported outcomes (ePRO) and passive data collection from a Fitbit device to identify disease worsening in a real-world study of participants (pts) with RA.

Objectives:

Evaluate agreement between self-reported new-onset flare and ePROs in an interim analysis from DIGITAL using a classification model.

Methods:

Members of the ArthritisPower registry with RA were invited to participate in DIGITAL. Pts who successfully completed a two-week Lead-in period entered the Main Study in which they wore a smartwatch and provided daily (pain and fatigue numeric rating scales (NRS)) and weekly ePROs, including the OMERACT RA Flare Questionnaire (FLARE) and PROMIS measures. This interim analysis is of ePRO data from pts who completed at least 30 days of the Main Study. A “Yes” response to the FLARE item, “Are you having a flare now?” identified flare. For modeling association between new-onset flare and ePRO, the dataset was split into training (the first 30 days of the Main Study) and test data (Day 31 and following). Within each dataset, repeated binary outcomes (Flare/No Flare) per pt were defined each week. To focus on new-onset flare, within each dataset, outcomes for patient weeks for which flare was present in the previous week were excluded.

Candidate variables for the model included baseline and current FLARE score (0-50 scale) and each of its 5 items, daily pain, daily fatigue, and several PROMIS weekly instruments and their lagged values (last week or last 6 days for daily). ‘Baseline’ was calculated in non-flare weeks. Training data was used for logistic regression model selection combining clinical expertise with backward elimination. Performance of the final model was evaluated using test data.

Results:

The training data was composed of outcomes from 128 pts who reported 388 weekly flare assessments as no flare or onset flare over 2800 days during the first month of the Main Study. Of pts in the training dataset, 92.2% were female, 87.5% white, with mean age (SD) 52.7 (11.0) and years since RA diagnosis 10.4 (10.3); 62.5% were on a biologic. Among those in the training dataset, 58 flare outcomes occurred in 50 (39.1%) unique pts.

The test data comprised outcomes from 123 pts who reported 442 weekly flare assessments as no flare or onset flare over 3366 days in which 64 flare outcomes occurred, and primarily included continued observations from pts who contributed to the training dataset.

The best-performing model to classify flare in training data included the current and baseline FLARE instrument activity question (i.e. “Considering how active your rheumatoid arthritis has been, how much difficulty have you had when taking part in activities such as work, family life, social events that are typical for you during the last week”), current daily pain, and baseline daily pain average and standard deviation. In test data, this model had an area under the receiver operator curve of 0.81 (Figure). At a cut point requiring specificity to be ≥0.80, sensitivity to detect flare was 0.62 and overall accuracy was 0.78.

Conclusion:

New-onset flare is common among RA patients, and the FLARE instrument and daily pain scores appear effective to classify it. Evaluation of passive data as a proxy for self-reported new-onset flare is ongoing.

References:

[1]Bartlett SJ, et al. JRheumatol, 2017;44:1536-43.

[2]Nowell WB, et al. JMIR Res Protoc, 2019;8:e14665.

Disclosure of Interests:

Virginia S. Haynes Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Jeffrey Curtis Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB, Fenglong Xie: None declared, Ilya Lipkovich Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Hong Zhao: None declared, Carol L. Kannowski Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Jiat-Ling Poon Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Kelly Gavigan: None declared, David Curtis: None declared, Sandra K. Nolot Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, W. Benjamin Nowell: None declared

Linear rheology as a potential monitoring tool for sputum in patients with Chronic Obstructive Pulmonary Disease (COPD)

BACKGROUND

The rheological properties of sputum may influence lung function and become modified in disease.

OBJECTIVE

This study aimed to correlate the viscoelastic properties of sputum with clinical data on the severity of disease in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Sputum samples from COPD patients were investigated using rheology, simple mathematical modelling and Scanning Electron Microscopy (SEM). The samples were all collected from patients within two days of their admission to Prince Philip Hospital due to an exacerbation of their COPD. Oscillatory and creep rheological techniques were used to measure changes in viscoelastic properties at different frequencies over time.

RESULTS

COPD sputum was observed to behave as a viscoelastic solid at all frequencies studied. Comparing the rheology of exacerbated COPD sputum with healthy sputum (not diagnosed with a respiratory disease) revealed significant differences in response to oscillatory shear and creep-recovery experiments, which highlights the potential clinical benefits of better understanding sputum viscoelasticity. A common power law model G(t)=G0(tτ0)-m was successfully fitted to experimental rheology data over the range of frequencies studied.

CONCLUSIONS

A comparison between clinical data and the power law index m obtained from rheology, suggested that an important possible future application of this parameter is as a potential biomarker for COPD severity.

Rare variant analysis in multiply affected families, association studies and functional analysis suggest a role for the ITGΒ4 gene in schizophrenia and bipolar disorder

Recent results imply that rare variants contribute to the risk of schizophrenia. Exome sequence data from the UK10K project was used to identify three rare, amino acid changing variants in the ITGB4 gene which segregated with schizophrenia in two families: rs750367954, rs147480547 and rs145976111. Association analysis was carried out in the exome-sequenced Swedish schizophrenia study and in UCL schizophrenia and bipolar cases and controls genotyped for these variants. A gene-wise weighted burden test was performed on a trio sample of schizophrenia cases and their parents. rs750367954 was seen in two Swedish cases and in no controls. The other two variants were commoner in cases than controls in both Swedish and UCL cohort samples and an overall burden test was significant at p=0.0000031. The variants were not observed in the trio sample but ITGB4 was most highly ranked out of 14,960 autosomal genes in a gene-wise weighted burden test. The effect of rs147480547 and rs145976111 was studied in human neuroblastoma SH-SY5Y cells. Cells transfected with both variants had increased proliferation at both 24 and 48h (p=0.013 and p=0.05 respectively) compared to those with wild-type ITGB4. Taken together, these results suggest that rare variants in ITGB4 which affect function may contribute to the aetiology of schizophrenia and bipolar disorder.

Urine and Serum Sex Steroid Profile in Testosterone-Treated Transgender and Hypogonadal and Healthy Control Men

BACKGROUND

The impact of testosterone (T) treatment on antidoping detection tests in female-to-male (F2M) transgender men is unknown. We investigated urine and serum sex steroid and luteinizing hormone (LH) profiles in T-treated F2M men to determine whether and, if so, how they differed from hypogonadal and healthy control men.

METHOD

Healthy transgender (n = 23) and hypogonadal (n = 24) men aged 18 to 50 years treated with 1000 mg injectable T undecanoate provided trough urine and blood samples and an additional earlier postinjection sample (n = 21). Healthy control men (n = 20) provided a single blood and urine sample. Steroids were measured by mass spectrometry-based methods in urine and serum, LH by immunoassay, and uridine 5'-diphospho-glucuronosyltransferase 2B17 genotype by polymerase chain reaction.

RESULTS

Urine LH, human chorionic gonadotropin, T, epitestosterone (EpiT), androsterone (A), etiocholanolone (Etio), A/Etio ratio, dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), and 5α,3α- and 5β,3α-androstanediols did not differ between groups or by time since last T injection. Urine T/EpiT ratio was <4 in all controls and 12/68 (18%) samples from T-treated men, but there was no difference between T-treated groups. Serum estradiol, estrone, and DHEA were higher in transgender men, and serum T and DHT were higher in earlier compared with trough blood samples, but serum LH, follicle-stimulating hormone, and 3α- and 3β,5α-diols did not differ between groups.

CONCLUSION

Urine antidoping detection tests in T-treated transgender men can be interpreted like those of T-treated hypogonadal men and are unaffected by time since last T dose. Serum steroids are more sensitive to detect exogenous T administration early but not later after the last T dose.

Genome-wide association study of borderline personality disorder reveals genetic overlap with bipolar disorder, major depression and schizophrenia

Borderline personality disorder (BOR) is determined by environmental and genetic factors, and characterized by affective instability and impulsivity, diagnostic symptoms also observed in manic phases of bipolar disorder (BIP). Up to 20% of BIP patients show comorbidity with BOR. This report describes the first case-control genome-wide association study (GWAS) of BOR, performed in one of the largest BOR patient samples worldwide. The focus of our analysis was (i) to detect genes and gene sets involved in BOR and (ii) to investigate the genetic overlap with BIP. As there is considerable genetic overlap between BIP, major depression (MDD) and schizophrenia (SCZ) and a high comorbidity of BOR and MDD, we also analyzed the genetic overlap of BOR with SCZ and MDD. GWAS, gene-based tests and gene-set analyses were performed in 998 BOR patients and 1545 controls. Linkage disequilibrium score regression was used to detect the genetic overlap between BOR and these disorders. Single marker analysis revealed no significant association after correction for multiple testing. Gene-based analysis yielded two significant genes: DPYD (P=4.42 × 10-7) and PKP4 (P=8.67 × 10-7); and gene-set analysis yielded a significant finding for exocytosis (GO:0006887, PFDR=0.019; FDR, false discovery rate). Prior studies have implicated DPYD, PKP4 and exocytosis in BIP and SCZ. The most notable finding of the present study was the genetic overlap of BOR with BIP (rg=0.28 [P=2.99 × 10-3]), SCZ (rg=0.34 [P=4.37 × 10-5]) and MDD (rg=0.57 [P=1.04 × 10-3]). We believe our study is the first to demonstrate that BOR overlaps with BIP, MDD and SCZ on the genetic level. Whether this is confined to transdiagnostic clinical symptoms should be examined in future studies.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.

Do we need a gender-specific total knee replacement? A randomised controlled trial comparing a high-flex and a gender-specific posterior design

The purpose of this study was to investigate whether a gender-specific high-flexion posterior-stabilised (PS) total knee replacement (TKR) would offer advantages over a high-flex PS TKR regarding range of movement (ROM), 'feel' of the knee, pain and satisfaction, as well as during activity. A total of 24 female patients with bilateral osteoarthritis entered this prospective, blind randomised trial in which they received a high-flex PS TKR in one knee and a gender-specific high-flexion PS TKR in the other knee. At follow-up, patients were assessed clinically measuring ROM, and questioned about pain, satisfaction and daily 'feel' of each knee. Patients underwent gait analysis pre-operatively and at one year, which yielded kinematic, kinetic and temporospatial parameters indicative of knee function during gait. At final follow-up we found no statistically significant differences in ROM (p = 0.82). The median pain score was 0 (0 to 8) in both groups (p = 0.95). The median satisfaction score was 9 (4 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.98). The median 'feel' score was 9 (3 to 10) in the high-flex group and 8 (0 to 10) in the gender-specific group (p = 0.66). Gait analysis showed no statistically significant differences between the two prosthetic designs in any kinematic, kinetic or temporospatial parameters. Both designs produced good clinical results with significant improvements in several gait parameters without evidence of any advantage in the gender-specific design.

Reduced functional loads alter the physical characteristics of the bone-periodontal ligament-cementum complex

BACKGROUND AND OBJECTIVE

Adaptive properties of the bone-periodontal ligament-tooth complex have been identified by changing the magnitude of functional loads using small-scale animal models, such as rodents. Reported adaptive responses as a result of lower loads due to softer diet include decreased muscle development, change in structure-function relationship of the cranium, narrowed periodontal ligament space, and changes in the mineral level of the cortical bone and alveolar jaw bone and in the glycosaminoglycans of the alveolar bone. However, the adaptive role of the dynamic bone-periodontal ligament-cementum complex to prolonged reduced loads has not been fully explained to date, especially with regard to concurrent adaptations of bone, periodontal ligament and cementum. Therefore, in the present study, using a rat model, the temporal effect of reduced functional loads on physical characteristics, such as morphology and mechanical properties and the mineral profiles of the bone-periodontal ligament-cementum complex was investigated.

MATERIAL AND METHODS

Two groups of 6-wk-old male Sprague-Dawley rats were fed nutritionally identical food with a stiffness range of 127-158 N/mm for hard pellet or 0.3-0.5 N/mm for soft powder forms. Spatio-temporal adaptation of the bone-periodontal ligament-cementum complex was identified by mapping changes in the following: (i) periodontal ligament collagen orientation and birefringence using polarized light microscopy, bone and cementum adaptation using histochemistry, and bone and cementum morphology using micro-X-ray computed tomography; (ii) mineral profiles of the periodontal ligament-cementum and periodontal ligament-bone interfaces by X-ray attenuation; and (iii) microhardness of bone and cementum by microindentation of specimens at ages 6, 8, 12 and 15 wk.

RESULTS

Reduced functional loads over prolonged time resulted in the following adaptations: (i) altered periodontal ligament orientation and decreased periodontal ligament collagen birefringence, indicating decreased periodontal ligament turnover rate and decreased apical cementum resorption; (ii) a gradual increase in X-ray attenuation, owing to mineral differences, at the periodontal ligament-bone and periodontal ligament-cementum interfaces, without significant differences in the gradients for either group; (iii) significantly (p < 0.05) lower microhardness of alveolar bone (0.93 ± 0.16 GPa) and secondary cementum (0.803 ± 0.13 GPa) compared with the higher load group insert bone = (1.10 ± 0.17 and cementum = 0.940 ± 0.15 GPa, respectively) at 15 wk, indicating a temporal effect of loads on the local mineralization of bone and cementum.

CONCLUSION

Based on the results from this study, the effect of reduced functional loads for a prolonged time could differentially affect morphology, mechanical properties and mineral variations of the local load-bearing sites in the bone-periodontal ligament-cementum complex. These observed local changes in turn could help to explain the overall biomechanical function and adaptations of the tooth-bone joint. From a clinical translation perspective, our study provides an insight into modulation of load on the complex for improved tooth function during periodontal disease and/or orthodontic and prosthodontic treatments.

Reactivity of Carbonaceous Anodes Used in Lithium-ion Batteries, Part I: Correlation of Structural Parameters and Reactivity

Carbonaceous anodes are the most practical elecrode for application in lithium-ion battery, mainly due to their low cost, flexibility for modification to achieve high energy capacity and high rate capability, abundance and environmentally uniquencess. Despite superior advantages of carbonaceous anodes vs other alternative anode and metallic lithium, there is considerable reactivity of lithiated graphite with organic electrolytes, which is a major safety concern. In this work, we report the nature of gaceous species generated on various carbonaceous anodes during initial charge-discharge cycling. The correlation between structural parameters of carbonaceous materials and their irreversible capacity loss have been investigated. Structural parameters have been studied using x-ray diffraction, Raman spectroscopy, and scanning and transmission electron microscopy. We have found a direct correlation between crystal morphology, degree of disorder, degree of graphitisation and the irreversible capacity loss. There is also a direct correlation between the irrversible capacity loss and the volume of gas generated during initial charge- disharge cycling. Results also show the importance of removing adsorbed and trapped gases in addition to removal of bonded impurities, such as functional groups from carbonaceous electrode before fabrication of batteries.

Particular attention is given on thermal analysis for different graphite compounds and the influence of different parameters and conditions: nature of graphite in term of specific surface area, degree of graphitization and the length of microcristallites, degree of intercalation, nature of electrolytes on irreversible capacity loss and volume of gases generated during the initial charge-discharge cycles.

A threonine to isoleucine missense mutation in the pericentriolar material 1 gene is strongly associated with schizophrenia

Markers at the pericentriolar material 1 gene (PCM1) have shown genetic association with schizophrenia in both a University College London (UCL) and a USA-based case-control sample. In this paper we report a statistically significant replication of the PCM1 association in a large Scottish case-control sample from Aberdeen. Resequencing of the genomic DNA from research volunteers who had inherited haplotypes associated with schizophrenia showed a threonine to isoleucine missense mutation in exon 24 which was likely to change the structure and function of PCM1 (rs370429). This mutation was found only as a heterozygote in 98 schizophrenic research subjects and controls out of 2246 case and control research subjects. Among the 98 carriers of rs370429, 67 were affected with schizophrenia. The same alleles and haplotypes were associated with schizophrenia in both the London and Aberdeen samples. Another potential aetiological base pair change in PCM1 was rs445422, which altered a splice site signal. A further mutation, rs208747, was shown by electrophoretic mobility shift assays to create or destroy a promoter transcription factor site. Five further non-synonymous changes in exons were also found. Genotyping of the new variants discovered in the UCL case-control sample strengthened the evidence for allelic and haplotypic association (P=0.02-0.0002). Given the number and identity of the haplotypes associated with schizophrenia, further aetiological base pair changes must exist within and around the PCM1 gene. PCM1 protein has been shown to interact directly with the disrupted-in-schizophrenia 1 (DISC1) protein, Bardet-Biedl syndrome 4, and Huntingtin-associated protein 1, and is important in neuronal cell growth. In a separate study we found that clozapine but not haloperidol downregulated PCM1 expression in the mouse brain. We hypothesize that mutant PCM1 may be responsible for causing a subtype of schizophrenia through abnormal cell division and abnormal regeneration in dividing cells in the central nervous system. This is supported by our previous finding of orbitofrontal volumetric deficits in PCM1-associated schizophrenia patients as opposed to temporal pole deficits in non-PCM1-associated schizophrenia patients. Caution needs to be exercised in interpreting the actual biological effects of the mutations we have found without further cell biology. However, the DNA changes we have found deserve widespread genotyping in multiple case-control populations.

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.

Case-control studies show that a non-conservative amino-acid change from a glutamine to arginine in the P2RX7 purinergic receptor protein is associated with both bipolar- and unipolar-affective disorders

Three linkage studies of bipolar disorder have implicated chromosome 12q24.3 with lod scores of over 3.0 and several other linkage studies have found lods between 2 and 3. Fine mapping within the original chromosomal linkage regions has identified several loci that show association with bipolar disorder. One of these is the P2RX7 gene encoding a central nervous system-expressed purinergic receptor. A non-synonymous single nucleotide polymorphism, rs2230912 (P2RX7-E13A, G allele) and a microsatellite marker NBG6 were both previously found to be associated with bipolar disorder (P=0.00071 and 0.008, respectively). rs2230912 has also been found to show association with unipolar depression. The effect of the polymorphism is non-conservative and results in a glutamine to arginine change (Gln460Arg), which is likely to affect P2RX7 dimerization and protein-protein interactions. We have confirmed the allelic associations between bipolar disorder and the markers rs2230912 (P2RX7-E13A, G allele, P=0.043) and NBG6 (P=0.010) in a London-based sample of 604 bipolar cases and 560 controls. When we combined these data with the published case-control studies of P2RX7 and mood disorder (3586 individuals) the association between rs2230912 (Gln460Arg) and affective disorders became more robust (P=0.002). The increase in Gln460Arg was confined to heterozygotes rather than homozygotes suggesting a dominant effect (odds ratio 1.302, CI=1.129-1.503). Although further research is needed to prove that the Gln460Arg change has an aetiological role, it is so far the most convincing mutation to have been found with a role for increasing susceptibility to bipolar and genetically related unipolar disorders.

Whole-genome association study of bipolar disorder

We performed a genome-wide association scan in 1461 patients with bipolar (BP) 1 disorder, 2008 controls drawn from the Systematic Treatment Enhancement Program for Bipolar Disorder and the University College London sample collections with successful genotyping for 372,193 single nucleotide polymorphisms (SNPs). Our strongest single SNP results are found in myosin5B (MYO5B; P=1.66 x 10(-7)) and tetraspanin-8 (TSPAN8; P=6.11 x 10(-7)). Haplotype analysis further supported single SNP results highlighting MYO5B, TSPAN8 and the epidermal growth factor receptor (MYO5B; P=2.04 x 10(-8), TSPAN8; P=7.57 x 10(-7) and EGFR; P=8.36 x 10(-8)). For replication, we genotyped 304 SNPs in family-based NIMH samples (n=409 trios) and University of Edinburgh case-control samples (n=365 cases, 351 controls) that did not provide independent replication after correction for multiple testing. A comparison of our strongest associations with the genome-wide scan of 1868 patients with BP disorder and 2938 controls who completed the scan as part of the Wellcome Trust Case-Control Consortium indicates concordant signals for SNPs within the voltage-dependent calcium channel, L-type, alpha 1C subunit (CACNA1C) gene. Given the heritability of BP disorder, the lack of agreement between studies emphasizes that susceptibility alleles are likely to be modest in effect size and require even larger samples for detection.

Investigation into the ability of SNP chipsets and microsatellites to detect association with a disease locus

We wished to investigate the ability of different SNP chipsets to detect association with a disease and to investigate the linkage disequilibrium (LD) relationships between microsatellites and nearby SNPs in order to assess their potential usefulness to detect association.

SNP genotypes were obtained from HapMap and microsatellite genotypes from CEPH. 5000 SNPs were simulated as disease genes which increased penetrance from 0.01 to 0.02 in a sample of 400 cases and 400 controls. The power of flanking SNPs to detect association was tested using sets of 1, 2, 3 or 4 markers analysed with haplotype analysis or logistic regression and using either all HapMap markers or those from the Affymetrix 500K, Illumina 300K or Illumina 550K chipsets. Additionally, LD relationships between 10 microsatellites and SNPs within 2Mb of each other were studied.

The power for one of the markers to detect association at p = 0.001 was around 0.4. Power was slightly better for logistic regression than haplotype analysis and for two-marker as opposed to single marker analysis but analysing with larger numbers markers had little benefit. The Illumina 550K marker set was better able to detect association than the other two and was almost as powerful as using all HapMap markers. Microsatellites had detectable LD with only a small number of nearby SNPs and the pattern of LD was very variable.

Available chipsets have quite good ability to detect association although obviously results will be critically dependent on the nature of the genetic effect on risk, sample size and the actual LD relationships of the susceptibility polymorphisms involved. Microsatellites seem ill-suited for systematic studies to detect association.

Study of regions of extended homozygosity provides a powerful method to explore haplotype structure of human populations

Previous investigations have reported linkage disequilibrium occurring between nearby polymorphisms, a block-like structure for such relationships, some instances where surprisingly few haplotypes are found and regions of extended homozygosity which are especially marked around centromeres and which are especially common on the X chromosome. We investigated the distribution and nature of regions of extended homozygosity in a sample of 1411 subjects included in a genome wide association study. Regions of extended homozygosity over 1Mb are common, with an average of 35.9 occurring per subject, and containing on average 73 homozygous markers. They have a markedly non-random distribution. They are relatively common on the X chromosome and are seen at centromeres but are also concentrated at other chromosomal regions where presumably recombination is rare. They seem to be a consequence of some haplotypes being very common in the population and although sometimes this reflects the effect of a very common haplotype we also note that there are examples of two or three common haplotypes, each very different from each other, underlying this effect. Regions of extended homozygosity are commoner than previously appreciated. They result from the presence of extended haplotypes with high population frequency. Such regions concentrate in particular locations. The haplotypes involved are sometimes markedly disparate from each other. These regions offer a valuable opportunity for further investigation, in particular with regard to their ancestral history.

Investigation of the ability of haplotype association and logistic regression to identify associated susceptibility loci

While finely spaced markers are increasingly being used in case-control association studies in attempts to identify susceptibility loci, not enough is yet known as to the optimal spacing of such markers, their likely power to detect association, the relative merits of single marker versus multimarker analysis, or which methods of analysis may be optimal. Some investigations of these issues have used markers simulated under different theoretical models of population evolution. However the HapMap project and other sources provide real datasets which can be used to obtain a more realistic view of the performance of these approaches. SNPs around APOE and from two HapMap regions were used to obtain information regarding linkage disequilibrium (LD) relationships between polymorphisms, and these real patterns of LD were used to simulate datasets such as would be obtained in case-control studies were these SNPs to influence susceptibility to disease. The datasets obtained were analysed using tests for heterogeneity of estimated haplotype frequencies and using logistic regression analyses in which only main effects from each marker were considered. All markers surrounding the putative susceptibility locus were analysed, using sets of either 1, 2, 3 or 4 markers at a time. Some markers within 150 kb of the susceptibility locus were able to detect association. At distances less than 100 kb there was no correlation between the distance from the susceptibility locus and the strength of evidence for association. When the average inter-locus spacing is 25 kb many loci would not be detected, while when the spacing is as low as 2 kb one can be fairly confident that at least one marker will be in strong enough LD with the susceptibility locus to enable association to be detected, if the susceptibility locus has a strong enough effect relative to the sample size. With an inter-locus spacing of 4 kb some susceptibility loci did not have a marker locus in strong LD, potentially undermining the ability to detect association. There was little difference in the performance of haplotype-based analysis compared with logistic regression considering effects of each marker as separate. Multimarker analysis on occasion produced results which were much more highly significant than single marker analysis, but only very rarely. Our results support the view that if markers are randomly selected then a spacing as low as 2 kb is desirable. Multimarker analysis can sometimes be more powerful than single marker analysis so both should be performed. However, because it is rare for multimarker analysis to be much more highly significant than single marker analysis one should strongly suspect that when such results occur they may be due to mistakes in genotyping or through some other artefact. Haplotype analysis may be more prone to such problems than logistic regression, suggesting that the latter method might be preferred.

Program report: GENECOUNTING support programs

We describe a suite of programs which enhance the usability of GENECOUNTING, a program for estimating haplotype frequencies in unrelated subjects. The programs, called RUNGC, SCANASSOC, COMPGR, SCANGROUP and LDPAIRS, carry out likelihood ratio tests and permutation tests to detect differences in haplotype frequencies between cases and controls,or between predefined groups, and output likely haplotype assignments and tables of linkage disequilibrium statistics between all pairs of markers in a dataset.

Fine mapping of a susceptibility locus for bipolar and genetically related unipolar affective disorders, to a region containing the C21ORF29 and TRPM2 genes on chromosome 21q22.3

Linkage analyses of bipolar families have confirmed that there is a susceptibility locus near the telomere on chromosome 21q. To fine map this locus we carried out tests of allelic association using 30 genetic markers near the telomere at 21q22.3 in 600 bipolar research subjects and 450 ancestrally matched supernormal control subjects. We found significant allelic association with the microsatellite markers D21S171 (P=0.016) and two closely linked single-nucleotide polymorphisms, rs1556314 (P=0.008) and rs1785467 (P=0.025). A test of association with a three locus haplotype across the susceptibility region was significant with a permutation test of P=0.011. A two SNP haplotype was also significantly associated with bipolar disorder (P=0.01). Only two brain expressed genes, TRPM2 and C21ORF29 (TSPEAR), are present in the associated region. TRPM2 encodes a calcium channel receptor and TSPEAR encodes a peptide with repeats associated with epilepsy in the mouse. DNA from subjects who had inherited the associated marker alleles was sequenced. A base pair change (rs1556314) in exon 11 of TRPM2, which caused a change from an aspartic acid to a glutamic acid at peptide position 543 was found. This SNP showed the strongest association with bipolar disorder (P=0.008). Deletion of exon 11 of TRPM2 is known to cause dysregulation of cellular calcium homeostasis in response to oxidative stress. A second nonconservative change from arginine to cysteine at position 755 in TRPM2 (ss48297761) was also detected. A third nonconservative change from histidine to glutamic acid was found in exon 8 of TSPEAR. These changes need further investigation to establish any aetiological role in bipolar disorder.

Further investigation of linkage disequilibrium SNPs and their ability to identify associated susceptibility loci

There is currently considerable interest in the use of single-nucleotide polymorphisms (SNPs) to map disease susceptibility genes. The success of this method will depend on a number of factors including the strength of linkage disequilibrium (LD) between marker and disease loci. We used a data set of SNP genotypings in the region of the APOE disease susceptibility locus to investigate the likely usefulness of SNPs in case-control studies. Using the estimated haplotype structure surrounding and including the APOE locus, and assuming a codominant disease model, we treated each SNP in turn as if it were a disease susceptibility locus and obtained, for each disease locus and markers, the expected likelihood ratio test (LRT) to assess disease association. We were particularly interested in the power to detect association with the susceptibility polymorphism itself, the power of nearby markers to detect association, and the ability to distinguish between the susceptibility polymorphism and marker loci also showing association. We found that the expected LRT depended critically on disease allele frequencies. For disease loci with a reasonably common allele we were usually able to detect association. However, for only a subset of markers in the close neighbourhood of the disease locus was association detectable. In these cases we were usually, but not always, able to distinguish the disease locus from nearby associated marker loci. For some disease loci, no other loci demonstrated detectable association with the disease phenotype. We conclude that one may need to use very dense SNP maps in order to avoid overlooking polymorphisms affecting susceptibility to a common phenotype.

Haplotype association analysis of discrete and continuous traits using mixture of regression models

We present a regression-based method of haplotype association analysis for quantitative and dichotomous traits in samples consisting of unrelated individuals. The method takes account of uncertain phase by initially estimating haplotype frequencies and obtaining the posterior probabilities of all possible haplotype combinations in each individual, then using these as weights in a finite mixture of regression models. Using this method, different combinations of marker loci can be modeled, to find a parsimonious set of marker loci that are most predictive and therefore most likely to be closely associated with the a quantitative trait locus. The method has the additional advantage of being able to use individuals with some missing genotype data, by considering all possible genotypes at the missing markers. We have implemented this method using the SNPHAP and Mx programs and illustrated its use on published data on idiopathic generalized epilepsy.

Genome scan of Tourette syndrome in a single large pedigree shows some support for linkage to regions of chromosomes 5, 10 and 13

OBJECTIVES

To localize genes influencing the susceptibility to Gilles de la Tourette syndrome (GTS) and associated chronic multiple tics (CMT).

METHOD

A single, large, multiple affected pedigree containing 35 subjects diagnosed with GTS and a further 14 with CMT was genotyped for markers spanning the autosomes. Linkage analysis was carried out using classical lod score analysis and model-free lod score analysis. All markers were subjected to two-point analysis, and markers producing a two-point result significant at P<0.005 were subjected to three-point analysis using adjacent markers.

RESULTS

The following markers produced at least one result significant at 0.005 using two-point analysis: D5S1981, D5S2050, D10S591, D10S189, D13S217, and D14S288. Three-point analysis with D5S2050 and D5S400 produced a lod of 2.9 with CMT. Three-point analysis of D10S591 and D10S189 produced lods of 1.9 with GTS and CMT. Three-point analysis of D13S217 and D13S171 produced a lod of 2.7 with GTS. No single haplotype appeared to account for the majority of cases within the pedigree.

CONCLUSIONS

It seems likely that more than one susceptibility allele is present in the pedigree. Although none of the three positive regions is conclusively implicated, it seems probable that at least one contains a susceptibility locus. We recommend that association-based studies be carried out in these three regions to produce further evidence for a localization and to carry out fine-mapping.

Coeliac disease: investigation of proposed causal variants in the CTLA4 gene region

Coeliac disease (CD) is an immune-mediated enteropathy triggered by gluten in genetically predisposed individuals. Patients with CD have an increased prevalence of other autoimmune disorders, including type 1 diabetes (T1D) and Graves' disease (GD). CD shares with these conditions certain HLA susceptibility alleles. A number of studies have also shown association of autoimmune diseases, including CD, with the CD28-cytotoxic T lymphocyte antigen 4 (CTLA4)-inducible costimulator (ICOS) region of chromosome 2q33, but until recently the precise causal variant has remained unknown. Recently, it was shown that, in GD, CT60 (+6230G>A), a single nucleotide polymorphism (SNP) at the end of the CTLA4 transcript, is associated with an alteration in the ratio of splice forms of the CTLA4 gene and that this ratio affects disease susceptibility. A similar but weaker association was found with T1D. There is also an independent association of GD and T1D with the SNP MH30 (-23 327G>C), which possibly affects promoter region function. Hypothesizing that CT60 and MH30 may be causal variants in other autoimmune disorders, we investigated these SNPs in CD using 149 family trios and 100 unrelated/unaffected controls. No association was detected with either SNP using both the transmission disequilibrium test (TDT) and case-control methods. Our study appears to have good power to detect moderate genetic effects, but possibly these SNPs exert too weak an effect on risk of CD to have been detected in our sample. Alternatively, the previously noted association of CD with the CTLA4 gene region may be due to different causal variants. Unlike T1D and GD, CD is not a true autoimmune disease, and CD has different associations at the CTLA4 exon 1 SNP +49G>A from all other autoimmune disorders. MH30, CT60, and other SNPs in the region may still warrant further investigation in other CD samples.

Assessing optimal neural network architecture for identifying disease-associated multi-marker genotypes using a permutation test, and application to calpain 10 polymorphisms associated with diabetes

Biallelic markers, such as single nucleotide polymorphisms (SNPs), provide greater information for localising disease loci when treated as multilocus haplotypes, but often haplotypes are not immediately available from multilocus genotypes in case-control studies. An artificial neural network allows investigation of association between disease phenotype and tightly linked markers without requiring haplotype phase and without modelling any evolutionary history for the disease-related haplotypes. The network assesses whether marker haplotypes differ between cases and controls to the extent that classification of disease status based on multi-marker genotypes is achievable. The network is "trained" to "recognise" affection status based on supplied marker genotypes, and then for each multi-marker genotype it produces outputs which aim to approximate the associated affection status. Next, the genotypes are permuted relative to affection status to produce many random datasets and the process of training and recording of outputs is repeated. The extent to which the ability to predict affection for the real dataset exceeds that for the random datasets measures the statistical significance of the association between multi-marker genotype and affection. This permutation test performs well with simulated case-control datasets, particularly when major gene effects are present. We have explored the effects of systematically varying different network parameters in order to identify their optimal values. We have applied the permutation test to 4 SNPs of the calpain 10 (CAPN10) gene typed in a case-control sample of subjects with type 2 diabetes, impaired glucose tolerance, and controls. We show that the neural network produces more highly significant evidence for association than do single marker tests corrected for the number of markers genotyped. The use of a permutation test could potentially allow conditional analyses which could incorporate known risk factors alongside marker genotypes. Permuting only the marker genotypes relative to affection status and these risk factors would allow the contribution of the markers to disease risk to be independently assessed.

Variation in the DCP1 gene, encoding the angiotensin converting enzyme ACE, is not associated with increased susceptibility to Alzheimer's disease

OBJECTIVES

To attempt to replicate previous reports that polymorphic variation in the DCP1 gene causes increased susceptibility to the development of Alzheimer's disease, either on its own or in interaction with the effects of the gene for apolipoprotein E (APOE).

METHOD

Subjects older than 65 years of age consisting of 81 dementia patients diagnosed as having possible or probable Alzheimer's disease and 68 controls were obtained from Camden, Islington and Harlow psychiatric services. Subjects were genotyped for APOE alleles e2, e3 and e4, and the common insertion/deletion polymorphisms for DCP1* I/D were genotyped.

RESULTS

There was no statistically significant difference in the frequency of the DCP1* insertion/deletion alleles between the cases and controls (X2 =0.04, 1 degree of freedom, not significant). When subjects were subdivided according to whether they possessed at least one copy of the APOE e4 allele, there were still no differences in DCP1 allele frequencies between cases and controls.

CONCLUSIONS

Further research is needed to elucidate any role that the DCP1 polymorphism may play in relation to Alzheimer's disease. Previous studies may be false positive, or inconsistency in replication may be due to heterogeneity.

Analysis of candidate genes on chromosome 19 in coeliac disease: an association study of the KIR and LILR gene clusters

Coeliac disease is strongly heritable, with more than half of the genetic susceptibility estimated to come from genes outside the HLA region. Several candidate regions have been suggested from genome-wide linkage studies including chromosome 19q13.4 where linkage has been replicated between populations. The natural killer (NK) cell immunoglobulin-like receptors (KIRs) and leukocyte immunoglobulin-like receptor (LILR, also known as ILT and LIR) gene clusters lie within this region in the leukocyte receptor cluster (LRC). KIR molecules are involved in cytotoxic lymphocyte function and expressed by intraepithelial T and NK cells in the duodenum. We studied 132 unrelated UK Caucasian coeliac patients and their parents together with a control group of 171 UK Caucasians. PCR-SSP for KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL5, LILRA3 (ILT6), LILRA3 deletion and an LILRA3 exon 3 single nucleotide polymorphism (SNP) allowed classification of KIR genotypes into five categories and determination of homozygosity or heterozygosity for the common A and B type KIR haplotypes (as defined in the text) and for the LILRA3 deletion. Case-control analysis found no association of the five KIR genotype categories, the A or B KIR haplotypes, the LILRA3 gene deletion or the LILRA3 exon 3 SNP with coeliac disease. A transmission disequilibrium test also found no association of the A and B KIR haplotypes or the LILRA3 gene deletion with coeliac disease.

A quick and simple method for detecting subjects with abnormal genetic background in case-control samples

It is important that case-control samples be drawn from a genetically homogeneous population in order to avoid artefactual false positive results and to enhance power to detect disease mutations and markers in linkage disequilibrium with them. Tests which simply compare overall marker allele frequencies between cases and controls will fail to identify a relatively small number of subjects drawn from a different genetic background who could usefully be discarded from the sample. Such subjects can be identified using multilocus tests, but previously described tests have been unnecessarily complex and cumbersome for this simple application. We describe a straightforward test, implemented in the CHECKHET program, which uses a measure of genetic difference and permutation procedures to rapidly identify such subjects using genotypes from multiple unlinked markers. It seems to perform reasonably well on simulated data, and with real data appears to identify two abnormal subjects within a case-control sample. We recommend that such tests be routinely applied to case-control samples once sufficient numbers of markers have been genotyped within them.

Extension of conditional model-free likelihood-based linkage analysis to additive and other models

We have previously described extending our method of 'model-free' linkage analysis, implemented in the MFLINK program, in order to deal with liability classes. This allows a new form of conditional two-locus linkage analysis, meaning that the genotypes of a known risk locus can be used to define liability classes so that their effects can be incorporated in tests for linkage at additional loci. In this method, relationships between transmission models for different liability classes were constrained so that there was a constant multiplicative effect on penetrance values. Here we present further extensions to the method to allow for different relationships. In particular, rather than only having a multiplicative effect on risk of affection we now allow specification of a multiplicative effect on risk of non-affection, or a combination of both relationships, across liability classes. We now also allow specification of an additive effect on penetrance. By way of example, we apply these methods to genome scan data for Alzheimer's disease using apolipoprotein E genotype to define liability classes. We show that, although in general the different methods produce results which tend to be quite highly correlated, certain markers can produce quite different results according to the method applied and that these could well lead to differences of interpretation. Without knowing a priori which relationship is likely to be most appropriate to describe the overall combined effect of the two loci one might be obliged to apply a number of different methods. This in turn may lead to the familiar difficulties associated with multiple testing. Nevertheless, the new method allows researchers greater flexibility in analysing linkage data for diseases in which one or more risk polymorphisms have already been identified.

Emerging issues and future needs in humanitarian assistance

During the past two decades, there has been tremendous investment in the ability to intervene in disaster settings, and significant barriers remain to providing appropriate services to populations affected by natural and man-made calamities. Many of the barriers to providing effective assistance exist within the NGO community, and illustrate emerging needs for international agencies. These emerging needs include improving methods of recipient participation to promote the local health system, developing improved methods for quality assurance, enhancing options for personnel development, and addressing long-term needs of reconstruction and rehabilitation. Relief agencies face challenges on all levels to develop sound practices in providing humanitarian assistance that can lead to long-term benefits to populations affected by disaster.

A novel method of two-locus linkage analysis applied to a genome scan for late onset Alzheimer's disease

A number of methods have previously been described which carry out linkage analysis considering information for two or more loci simultaneously. Apart from some ad hoc methods such as analysing subsamples, these methods use information regarding linkage at all loci under consideration. However, if the actual genotype-specific effects are known for some loci then it would be preferable to consider the genotypes of these loci directly, rather than the amount of allele-sharing they demonstrate. Here we present an extension to our likelihood-based method of model-free linkage analysis as implemented in the MFLINK program. This allows the incorporation of liability classes. The genotypes of a locus known to affect risk can be used to assign subjects to liability classes prior to carrying out linkage tests at other loci. An example application is presented for genome scan data on Alzheimer's disease with analysis conditional on Apoliprotein E (APOE) genotypes. The results provide support for the existence of additional susceptibility loci linked to D10S1211 and to D12S358.

The effect of child characteristics on teachers' acceptability of classroom-based behavioral strategies and psychostimulant medication for the treatment of ADHD

Studied the effect of student characteristics on teachers' ratings of treatment acceptability for attention deficit hyperactivity disorder (ADHD). Participants (N = 159) included experienced elementary school teachers who read 1 of 6 vignettes describing a child with symptoms representative of ADHD. Vignettes varied by sex and symptom-subtype classification. However, the number and specific type of symptoms described in the vignettes were consistent across all conditions. Next, teachers read a description of a daily report card (DRC), response cost technique, classroom lottery, and medication and rated their levels of agreement to the items of the Behavioral Intervention Rating Scale (BIRS). Teachers preferred the DRC to all other forms of treatment. However, there was a significant interaction between the type of treatment and sex of the student on the 3 factors (Treatment Acceptability, Treatment Effectiveness, and Timeliness) of the BIRS.