Microbial diversity and antimicrobial resistance in faecal samples from acute medical patients assessed through metagenomic sequencing

Antimicrobial resistance (AMR) is a threat to global public health. However, unsatisfactory approaches to directly measuring the AMR burden carried by individuals has hampered efforts to assess interventions aimed at reducing selection for AMR. Metagenomics can provide accurate detection and quantification of AMR genes within an individual person's faecal flora (their gut "resistome"). Using this approach, we aimed to test the hypothesis that differences in antimicrobial use across different hospitals in the United Kingdom will result in observable differences in the resistome of individual patients. Three National Health Service acute Hospital Trusts with markedly different antibiotic use and Clostridioides difficile infection rates collected faecal samples from anonymous patients which were discarded after C. difficile testing over a period of 9 to 15 months. Metagenomic DNA was extracted from these samples and sequenced using an Illumina NovaSeq 6000 platform. The resulting sequencing reads were analysed for taxonomic composition and for the presence of AMR genes. Among 683 faecal metagenomes we found huge variation between individuals in terms of taxonomic diversity (Shannon Index range 0.10-3.99) and carriage of AMR genes (Median 1.50 genes/cell/sample overall). We found no statistically significant differences in diversity (median Shannon index 2.16 (IQR 1.71-2.56), 2.15 (IQR 1.62-2.50) and 2.26 (IQR 1.55-2.51)) or carriage of AMR genes (median 1.37 genes/cell/sample (IQR 0.70-3.24), 1.70 (IQR 0.70-4.52) and 1.43 (IQR 0.55-3.71)) at the three trusts respectively. This was also the case across the sample collection period within the trusts. While we have not demonstrated differences over place or time using metagenomic sequencing of faecal discards, other sampling frameworks may be more suitable to determine whether organisational level differences in antibiotic use are associated with individual-level differences in burden of AMR carriage.

Automated referral to community paramedicine during 9-1-1 fall calls for resource activation

BACKGROUND

We sought to improve the referral process to a community paramedicine (CP) program following a 9-1-1 encounter.

METHODS

An electronic health record (EHR) for CP records with the ability to link to emergency EHR was identified and implemented with a single-click referral to the CP program. Referrals were tracked for 15 months before and after implementation.

RESULTS

Referral capacity increased from an average of 14.2 referrals per month to 44.9 referrals per month.

CONCLUSION

The results of this study suggest an EHR is a useful investment for CP programs and may be integral to efficient program operations.

Review of the clinical spectrum of typical and atypical Lyme neuroborreliosis in southwest England

Background

Lyme disease is endemic in the UK with a high incidence in southwest England. Neurological involvement occurs in approximately 5% of infected individuals. Previous reviews in southwest England have shown a consistent phenotype in most cases, however anecdotal review suggests a small number of atypical cases, with diverse presentations, which provide a diagnostic challenge, even to experienced neurologists.

Methods

We performed a retrospective, observational study of all identified cases (positive screening ELISA confirmed by immunoblot and neurological symptoms) of neuroborreliosis from six hospitals between January 2015 and December 2017. In addition, we reviewed atypical cases seen over the last decade in the regional neurosciences centre in depth.

Results

72 patients were included in the observational study. 83% had characteristics of Bannwarth’s syndrome (cranial neuropathy, radiculopathy and CSF pleocytosis). Unusual cases included mononeu- ritis multiplex.

Central nervous system involvement was rare. We saw cases presenting with cerebrovascular events, meningitis and encephalitis. Complete resolution of symptoms was reported in 72% of patients. 28% of patients reported residual symptoms, most commonly fatigue and memory problems.

Conclusions

This is the largest UK review of neuroborreliosis. The presentation is usually typical, but atypical presentations vary and can be challenging. The majority of patients recover fully.

amyrossrussell@gmail.com

Prevalence of insertion sequence elements in plasmids relating to mgrB gene disruption causing colistin resistance in Klebsiella pneumoniae

Colistin is a last resort antibiotic for the treatment of carbapenemase producing Klebsiella pneumoniae. The disruption of the mgrB gene by insertion sequences (ISs) is a mechanism mediating colistin resistance. Plasmids encode mobilizable IS elements which integrate into the mgrB gene in K. pneumoniae causing gene inactivation and colistin resistance. The species prevalence of mgrB-gene disrupting insertion elements ISL3 (ISKpn25), IS5 (ISKpn26), ISKpn14, and IS903B present on plasmids were assessed. IS containing plasmids were also scanned for antimicrobial resistance genes, including carbapenem resistant genes. Plasmids encoding ISs are abundant in K. pneumoniae. IS903B was found in 28 unique Inc groups, while ISKpn25 was largely carried by IncFIB(pQil) plasmids. ISKpn26 and ISKpn14 were most often found associated with IncFII(pHN7A8) plasmids. Of the 34 unique countries which contained any of the IS elements, ISKpn25 was identified from 26. ISKpn26, ISKpn14, and IS903B ISs were identified from 89.3%, 44.9%, and 23.9% plasmid samples from China. Plasmids carrying ISKpn25, ISKpn14, and ISKpn26 IS have a 4.6-, 6.0-, and 6.6-fold higher carbapenemase gene count, respectively, relative to IS903B-carrying plasmids. IS903B bearing plasmids have a 20-, 5-, and 5-fold higher environmental source isolation count relative to ISKpn25, ISKpn14, and ISKpn26 bearing plasmids. ISKpn25 present on IncFIB(pQil) sourced from clinical settings is established across multiple countries, while ISKpn26, ISKpn14, and IS903B appear most often in China. Carbapenemase presence in tandem with IS elements may help promote an extensively drug resistant profile in K. pneumoniae limiting already narrow treatment options.

Assessment of Fall-Related Emergency Medical Service Calls and Transports after a Community-Level Fall-Prevention Initiative

Background: Getting effective fall prevention into the homes of medically and physically vulnerable individuals is a critical public health challenge. Community paramedicine is emerging globally as a new model of care that allows emergency medical service units to evaluate and treat patients in non-emergency contexts for prevention efforts and chronic care management. The promise of community paramedicine as a delivery system for fall prevention that scales to community-level improvements in outcomes is compelling but untested.Objective: To study the impact of a community paramedic program's optimization of a fall prevention system entailing a clinical pathway and learning health system (called Community-FIT) on community-level fall-related emergency medical service utilization rates.Methods: We used an implementation science framework and quality improvement methods to design and optimize a fall prevention model of care that can be embedded within community paramedic operations. The model was implemented and optimized in an emergency medical service agency servicing a Midwestern city in the United States (∼35,000 residents). Primary outcome measures included relative risk reduction in the number of community-level fall-related 9-1-1 calls and fall-related hospital transports. Interrupted time series analysis was used to evaluate relative risk reduction from a 12-month baseline period (September 2016 - August 2017) to a 12-month post-implementation period (September 2018-August 2019).Results: Community paramedic home visits increased from 25 in 2017, to 236 in 2018, to 517 in 2019, indicating a large increase in the number of households that benefited from the efforts. A relative risk reduction of 0.66 (95% [CI] 0.53, 0.76) in the number of fall calls and 0.63 (95% [CI] 0.46, 0.75) in the number of fall-related calls resulting in transports to the hospital were observed.Conclusions: Community-FIT may offer a powerful mechanism for community paramedics to reduce fall-related 9-1-1 calls and transports to hospitals that can be implemented in emergency medical agencies across the country.

Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial

Importance

Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist.

Objective

To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections.

Design, Setting, and Participants

This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers.

Interventions

A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder.

Main Outcomes and Measures

The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence.

Results

The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections.

Conclusions and Relevance

Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin.

Trial Registration

ClinicalTrials.gov Identifier: NCT02227446.

Barriers to the Initiation of Home Modifications for Older Adults for Fall Prevention

Introduction:

Home modifications are associated with decreased risk for falls and facilitate safe aging in place. The purpose of this study was to identify barriers to procurement of home modifications for older adults.

Materials and Methods:

Cross-sectional interviews by 2 separate (1 male and 1 female) researchers in a Midwestern city of home repair (“handyman”) and construction businesses within 15 miles of the areas of interest (neighborhood with a high socioeconomic status and neighborhood with low socioeconomic status) with a publicly listed phone number (n = 98). Estimated cost, earliest date of installation, and duration for a home modification project (installation of 3 grab bars) were collected.

Results:

At least 1 response was attained only 43% of the time (n = 42), and residential grab bar installations were not provided by most businesses (n = 24). The average quote for materials and labor was $394.31 (range $125-$1300). Five of the 7 businesses that responded to both researchers with the same representative differed in cost estimates, generally offering a reduced quote for the low socioeconomic status neighborhood by as much as $300. Quotes provided to the female researcher were also higher than those obtained by the male researcher by about $30 regardless of socioeconomic status. The average wait for home modifications was 23 days and the average anticipated duration of the project was 2.6 hours.

Discussion:

There are financial and procedural barriers to accessing home modifications for older adults who independently attempt to acquire them. There is a need for pathways in clinical and community settings to reduce barriers to home modifications to reduce the risk of falls.

Conclusion:

Home modifications are a promising tool to reduce falls and fall-related injuries in older adults. However, further work to identify cost-effective and timely options to reduce acquisition barriers is necessary to leverage the preventive power of home modifications.

Effect of Cognitive Prehabilitation on the Incidence of Postoperative Delirium Among Older Adults Undergoing Major Noncardiac Surgery: The Neurobics Randomized Clinical Trial

Importance

Postoperative delirium in older adults is a common and costly complication after surgery. Cognitive reserve affects the risk of postoperative delirium, and thus preoperative augmentation of reserve as a preventive technique is of vital interest.

Objective

To determine whether cognitive prehabilitation reduces the incidence of postoperative delirium among older adults.

Design, Setting, and Participants

This was a prospective, single-blinded randomized clinical trial conducted from March 2015 to August 2019 at the Ohio State University Wexner Medical Center in Columbus. Patients 60 years and older undergoing major, noncardiac, nonneurological surgery under general anesthesia, with an expected hospital stay of at least 72 hours, were eligible for trial inclusion. Patients were excluded for preoperative cognitive dysfunction and active depression.

Interventions

Participation in electronic, tablet-based preoperative cognitive exercise targeting memory, speed, attention, flexibility, and problem-solving functions.

Main Outcomes and Measures

The primary outcome was incidence of delirium between postoperative day 0 to day 7 or discharge, as measured by a brief Confusion Assessment Method, Memorial Delirium Assessment Scale, or a structured medical record review. Secondary outcomes compared delirium characteristics between patients in the intervention and control groups.

Results

Of the 699 patients approached for trial participation, 322 completed consent and 268 were randomized. Subsequently, 17 patients were excluded, leaving 251 patients in the primary outcome analysis. A total of 125 patients in the intervention group and 126 control patients were included in the final analysis (median [interquartile range] age, 67 [63-71] years; 163 women [64.9%]). Ninety-seven percent of the patients in the intervention group completed some brain exercise (median, 4.6 [interquartile range, 1.31-7.4] hours). The delirium rate among control participants was 23.0% (29 of 126). With intention-to-treat analysis, the delirium rate in the intervention group was 14.4% (18 of 125; P = .08). Post hoc analysis removed 4 patients who did not attempt any cognitive exercise from the intervention group, yielding a delirium rate of 13.2% (16 of 121; P = .04). Secondary analyses among patients with delirium showed no differences in postoperative delirium onset day or duration or total delirium-positive days across study groups.

Conclusions and Relevance

The intervention lowered delirium risk in patients who were at least minimally compliant. The ideal activities, timing, and effective dosage for cognitive exercise-based interventions to decrease postoperative delirium risk and burden need further study.

Trial Registration

ClinicalTrials.gov Identifier: NCT02230605.

Cost-benefit analysis of surveillance for surgical site infection following caesarean section

OBJECTIVE

To estimate the economic burden to the health service of surgical site infection following caesarean section and to identify potential savings achievable through implementation of a surveillance programme.

DESIGN

Economic model to evaluate the costs and benefits of surveillance from community and hospital healthcare providers' perspective.

SETTING

England.

PARTICIPANTS

Women undergoing caesarean section in National Health Service hospitals.

MAIN OUTCOME MEASURE

Costs attributable to treatment and management of surgical site infection following caesarean section.

RESULTS

The costs (2010) for a hospital carrying out 800 caesarean sections a year based on infection risk of 9.6% were estimated at £18 914 (95% CI 11 521 to 29 499) with 28% accounted for by community care (£5370). With inflation to 2019 prices, this equates to an estimated cost of £5.0 m for all caesarean sections performed annually in England 2018-2019, approximately £1866 and £93 per infection managed in hospital and community, respectively. The cost of surveillance for a hospital for one calendar quarter was estimated as £3747 (2010 costs). Modelling a decrease in risk of infection of 30%, 20% or 10% between successive surveillance periods indicated that a variable intermittent surveillance strategy achieved higher or similar net savings than continuous surveillance. Breakeven was reached sooner with the variable surveillance strategy than continuous surveillance when the baseline risk of infection was 10% or 15% and smaller loses with a baseline risk of 5%.

CONCLUSION

Surveillance of surgical site infections after caesarean section with feedback of data to surgical teams offers a potentially effective means to reduce infection risk, improve patient experience and save money for the health service.

Developing a serocorrelate of protection against invasive group B streptococcus disease in pregnant women: a feasibility study

BACKGROUND

Group B streptococcus is the leading cause of infection in infants. Currently, intrapartum antibiotic prophylaxis is the major strategy to prevent invasive group B streptococcus disease. However, intrapartum antibiotic prophylaxis does not prevent maternal sepsis, premature births, stillbirths or late-onset disease. Maternal vaccination may offer an alternative strategy. Multivalent polysaccharide protein conjugate vaccine development is under way and a serocorrelate of protection is needed to expedite vaccine licensure.

OBJECTIVES

The ultimate aim of this work is to determine the correlate of protection against the major group B streptococcus disease-causing serotypes in infants in the UK. The aim of this feasibility study is to test key operational aspects of the study design.

DESIGN

Prospective cohort study of pregnant women and their infants in a 6-month period (1 July to 31 December 2018).

SETTING

Five secondary and tertiary hospitals from London and South England. National iGBS disease surveillance was conducted in all trusts in England and Wales.

PARTICIPANTS

Pregnant women aged ≥ 18 years who were delivering at one of the selected hospitals and who provided consent during the study period. There were no exclusion criteria.

INTERVENTIONS

No interventions were performed.

MAIN OUTCOME MEASURES

(1) To test the feasibility of collecting serum at delivery from a large cohort of pregnant women. (2) To test the key operational aspects for a proposed large serocorrelates study. (3) To test the feasibility of collecting samples from those with invasive group B streptococcus.

RESULTS

A total of 1823 women were recruited during the study period. Overall, 85% of serum samples were collected at three sites collecting only cord blood. At the two sites collecting maternal, cord and infant blood samples, the collection rate was 60%. A total of 614 women were screened for group B streptococcus with a colonisation rate of 22% (serotype distribution: 30% III, 25% Ia, 16% II, 14% Ib, 14% V and 1% IV). A blood sample was collected from 34 infants who were born to colonised women. Maternal and infant blood and the bacterial isolates for 15 newborns who developed invasive group B streptococcal disease during the study period were collected (serotype distribution: 29% III, 29% II, 21% Ia, 7% Ib, 7% IV and 7% V).

LIMITATIONS

Recruitment and sample collection were dependent on the presence of research midwives rather than the whole clinical team. In addition, individualised consent limited the number of women who could be approached each day, and site set-up for the national surveillance study and the limited time period of this feasibility study limited recruitment of all eligible participants.

CONCLUSIONS

We have verified the feasibility of collecting and processing rectovaginal swabs and blood samples in pregnant women, as well as samples from those with invasive group B streptococcal disease. We have made recommendations for the recruitment of cases within the proposed GBS3 study and for controls both within GBS3 and as an extension of this feasibility study.

FUTURE WORK

A large case-control study comparing specific immunoglobulin G levels in mothers whose infants develop invasive group B streptococcal disease with those in colonised mothers whose infants do not develop invasive group B streptococcal disease is recommended.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49326091; IRAS project identification number 246149/REC reference number 18/WM/0147.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 67. See the NIHR Journals Library website for further project information.

Octogenarian and Nonagenarians Are at a Higher Risk for Experiencing Adverse 30-Day Outcomes Following ORIF for Ankle Fractures

Category:

Ankle, Trauma

Introduction/Purpose:

Despite an increasing number of elderly individuals undergoing surgical fixation for ankle fractures, few studies have investigated peri-operative outcomes and safety of surgery in an octogenarian and nonagenarian population (age >=80 years). Past literature has shown octogenarians to be a potentially vulnerable population that have drastically different adverse outcomes and higher resource utilization as compared to individuals below the age of 80 years.

Methods:

The 2012-2017 American College of Surgeons – National Surgical Quality Improvement Program (ACS-NSQIP) was queried using Current Procedural Terminology codes for patients undergoing open reduction internal fixation (ORIF) for isolated uni-malleolar (CPT-27766, CPT-27769, CPT-27792), bi-malleolar (CPT-27814) and tri-malleolar (CPT-27822, CPT-27823) ankle fractures. The study cohort was divided into three distinct groups for comparisons (Age <65 years, Age 65-79 years and Age=>80 years/octogenarians + nonagenarians). Multi-variate regression analyses were used to compare the independent effect of varying age groups on 30-day post-operative outcomes while controlling for differences in baseline clinical characteristics (age, gender, sex, race, fracture type/severity, open vs. closed fracture, admission status, BMI, co-morbidities, functional health status, ASA group and operative time). For comparison purposes, Age<65 years was taken as reference group in multi-variate regression models.

Results:

A total of 19,585 patients were included – out of which 1,033 (5.3%) were octogenarians/nonagenarians (=>80 years). Following multivariate analysis, individuals aged =>80 years were at a significantly higher risk of 30-day wound complications (OR 1.84; p=0.019), pulmonary complications (OR 3.88; p<0.001), renal complications (OR 1.96; p=0.015), septic complications (OR 3.72; p=0.002), urinary tract infections (OR 2.24; p<0.001), bleeding requiring transfusion (OR 1.90; p=0.025), mortality (OR 7.44; p<0.001), readmissions (OR 1.65; p=0.004) and non-home discharge (OR 13.91; p<0.001). Individuals between the age of 65-79 years only had a higher risk of pulmonary complications (OR 2.30; p=0.004), urinary tract infections (OR 2.24; p<0.001), readmissions (OR 1.41; p=0.005) and non-home discharges (OR 3.55; p<0.001), with the effect sizes being small as compared to age >=80 years group.

Conclusion:

Based on the findings, it appears that octagenarians and nonagenarians (age =>80) are a fundamentally distinct and vulnerable age group that is at a higher risk of complications, readmissions, mortality and non-home discharges as compared to other geriatric (65-79 years) and non-geriatric (<65 years) patients. Providers should understand the importance of pre-operative counselling and risk-stratification in this vulnerable patient population.

The role of sociodemographics in the occurrence of orthopaedic trauma

INTRODUCTION

We sought to determine the effects of sociodemographic factors on the occurrence of orthopaedic injuries in an adult population presenting to a level 1 trauma center.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients who received orthopaedic trauma care at a level 1 academic trauma center.

RESULTS

20,919 orthopaedic trauma injury cases were treated at an academic level 1 trauma center between 01 January 1993 and 27 August 2017. Following application of inclusion/exclusion criteria, a total of 14,654 patients were retrieved for analysis. Out of 14,654 patients, 4602 (31.4%) belonged to low socioeconomic status (SES), 4961 (32.0%) to middle SES and 5361 (36.6%) to high SES. Following adjustment for age, sex, race, insurance status and injury severity score (ISS), patients belonging to middle SES vs. low SES (OR 0.77 [95% CI 0.63-0.94]; p = 0.009) or high SES vs. low SES (OR 0.77 [95% CI 0.62-0.95]; p = 0.016) had lower odds of receiving a penetrating injury as compared to a blunt injury.

CONCLUSION

The results from this study indicate that a link exists between sociodemographic factors and the occurrence of orthopaedic injuries presenting to a level 1 trauma center. The most common cause of injury varied within age groups, by sex, and within the different socioeconomic groups.

A genome-wide association study identifies risk loci for childhood acute lymphoblastic leukemia at 10q26.13 and 12q23.1

Genome-wide association studies (GWASs) have shown that common genetic variation contributes to the heritable risk of childhood acute lymphoblastic leukemia (ALL). To identify new susceptibility loci for the largest subtype of ALL, B-cell precursor ALL (BCP-ALL), we conducted a meta-analysis of two GWASs with imputation using 1000 Genomes and UK10K Project data as reference (totaling 1658 cases and 7224 controls). After genotyping an additional 2525 cases and 3575 controls, we identify new susceptibility loci for BCP-ALL mapping to 10q26.13 (rs35837782, LHPP, P=1.38 × 10-11) and 12q23.1 (rs4762284, ELK3, P=8.41 × 10-9). We also provide confirmatory evidence for the existence of independent risk loci at 9p21.3, but show that the association marked by rs77728904 can be accounted for by linkage disequilibrium with the rare high-impact CDKN2A p.Ala148Thr variant rs3731249. Our data provide further insights into genetic susceptibility to ALL and its biology.

Castration-Resistant Prostate Cancer Tissue Acquisition From Bone Metastases for Molecular Analyses

Background

The urgent need for castration-resistant prostate cancer molecular characterization to guide treatment has been constrained by the disease's predilection to metastasize primarily to bone. We hypothesized that the use of clinical and imaging criteria could maximize tissue acquisition from bone marrow biopsies (BMBs). We aimed to develop a score for the selection of patients undergoing BMB.

Materials and Methods

A total of 115 BMBs were performed in 101 patients: 57 were included in a derivation set and 58 were used as the validation set. The clinical and laboratory data and prebiopsy computed tomography parameters (Hounsfield units [HUs]) were determined. A score for the prediction of biopsy positivity was developed from logistic regression analysis of the derivation set and tested in the validation set.

Results

Of the 115 biopsy specimens, 75 (62.5%) were positive; 35 (61.4%) in the test set and 40 (69%) in the validation set. On univariable analysis, hemoglobin (P = .019), lactate dehydrogenase (P = .003), prostate-specific antigen (P = .005), and mean HUs (P = .004) were selected. A score based on the LDH level (≥ 225 IU/L) and mean HUs (≥ 125) was developed in multivariate analysis and was associated with BMB positivity in the validation set (odds ratio, 5.1; 95% confidence interval, 1.9%-13.4%; P = .001). The area under the curve of the score was 0.79 in the test set and 0.77 in the validation set.

Conclusion

BMB of the iliac crest is a feasible technique for obtaining tumor tissue for genomic analysis in patients with castration-resistant prostate cancer metastatic to the bone. A signature based on the mean HUs and LDH level can predict a positive yield with acceptable internal validity. Prospective studies of independent cohorts are needed to establish the external validity of the score.

Determining the genome-wide kinship coefficient seems unhelpful in distinguishing consanguineous couples with a high versus low risk for adverse reproductive outcome

Background

Offspring of consanguineous couples are at increased risk of congenital disorders. The risk increases as parents are more closely related. Individuals that have the same degree of relatedness according to their pedigree, show variable genomic kinship coefficients. To investigate whether we can differentiate between couples with high- and low risk for offspring with congenital disorders, we have compared the genomic kinship coefficient of consanguineous parents with a child affected with an autosomal recessive disorder with that of consanguineous parents with only healthy children, corrected for the degree of pedigree relatedness.

Methods

151 consanguineous couples (73 cases and 78 controls) from 10 different ethnic backgrounds were genotyped on the Affymetrix platform and passed quality control checks. After pruning SNPs in linkage disequilibrium, 57,358 SNPs remained. Kinship coefficients were calculated using three different toolsets: PLINK, King and IBDelphi, yielding five different estimates (IBDelphi, PLINK (all), PLINK (by population), King robust (all) and King homo (by population)). We performed a one-sided Mann Whitney test to investigate whether the median relative difference regarding observed and expected kinship coefficients is bigger for cases than for controls. Furthermore, we fitted a mixed effects linear model to correct for a possible population effect.

Results

Although the estimated degrees of genomic relatedness with the different toolsets show substantial variability, correlation measures between the different estimators demonstrated moderate to strong correlations. Controls have higher point estimates for genomic kinship coefficients. The one-sided Mann Whitney test did not show any evidence for a higher median relative difference for cases compared to controls. Neither did the regression analysis exhibit a positive association between case–control status and genomic kinship coefficient.

Conclusions

In this case–control setting, in which we compared consanguineous couples corrected for degree of pedigree relatedness, a higher degree of genomic relatedness was not significantly associated with a higher likelihood of having an affected child. Further translational research should focus on which parts of the genome and which pathogenic mutations couples are sharing. Looking at relatedness coefficients by determining genome-wide SNPs does not seem to be an effective measure for prospective risk assessment in consanguineous parents.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0191-0) contains supplementary material, which is available to authorized users.

Diagnosis of fetal submicroscopic chromosomal abnormalities in failed array CGH samples: copy number by sequencing as an alternative to microarrays for invasive fetal testing

OBJECTIVES

Array comparative genomic hybridization (CGH) has become the technology of choice for high-resolution prenatal whole genome analysis. Limitations of microarrays are mainly related to the analog nature of the analysis, and poor-quality DNA can result in failed quality metrics with these platforms. We examined a cohort of abnormal fetuses with failed array CGH results using a next-generation sequencing algorithm, CNV-Seq. We assessed the ability of the platform to handle suboptimal prenatal samples and generate interpretable molecular karyotypes.

METHODS

Nine samples obtained from abnormal fetuses and one from a normal control fetus were sequenced using an Illumina GAIIx. A segmentation algorithm for sequencing data was used to determine regional copy number data on the sequencing datasets.

RESULTS

Phred quality scores were satisfactory for analysis of all samples. CNV-Seq identified both large- and small-scale abnormalities in the cohort, and normal results were obtained for fetuses for which microarray data were previously uninterpretable. No variants of uncertain significance were detected. Analysis of the digital sequencing datasets offered some advantages over array CGH output.

CONCLUSIONS

Using next-generation sequencing for the detection of genomic copy number variants may be advantageous for poor-quality, invasively-acquired prenatal samples. CNV-Seq could become a potential alternative to array CGH in this setting.

Acceptability of prenatal testing and termination of pregnancy in Pakistan

This study aimed to assess acceptability of prenatal testing (PNT) and termination of pregnancy (TOP) for a range of conditions in Pakistani parents with and without a child with a genetic condition. A structured questionnaire assessing acceptability of PNT and TOP for 30 conditions was completed by 400 Pakistani participants: 200 parents with a child with a genetic condition (100 fathers and 100 mothers) and 200 parents without an affected child (100 fathers and 100 mothers). There was a high level of interest in PNT, where over 80 % of parents in all four study groups would want PNT for the majority of the conditions. There was comparatively less interest in TOP for the same conditions (ranging from 5 to 70 % of parents, with mothers of an affected child being most interested). Parents were most likely to be interested in TOP for conditions at the serious end of the continuum. More than half of the participants in each group would consider TOP for anencephaly and quadriplegia. The interest in PNT and TOP for a range of conditions suggests that rapidly developing PNT technologies are likely to be acceptable in Pakistan, a low-middle income level and Muslim country. The comparatively lower level of interest in TOP for the same conditions highlights ethical dilemmas that such technologies are likely to raise.

Predicting positive bone marrow biopsies (BMBs) in patients (PTS) with advanced prostate cancer (APC)

180

Background: Advanced prostate cancer (APC) is a molecularly heterogeneous disease, with evidence of clonal evolution that could be responsible for resistance to treatment. About 90% of patients (pts) with APC have bone metastases. The acquisition of a bone marrow biopsies (BMBs) is a safe and feasible technique for obtaining tissue, with a low rate of complications. We hypothesized that pre-biopsy clinical variables may increase the success rate of BMBs in APC. Methods: Standard BMBs of the iliac crest were performed in APC pts between October 2011 and June 2013. All pts signed ethics approved consent. In the control cohort (n=10) BMBs were collected in pts with normal CT and bone scan appearance. Minimum, maximum, and mean Hounsfield Units (HU) of the iliac crest on pre-biopsy CTs were determined. Clinical and laboratory variables were collected from the electronic record system. Biopsies were defined as containing 50 or more or 1 to 50 malignant cells or none (negative). Univariate analysis was performed to determine variables associated with biopsy positivity with 50 or more cells. For variables with p value<0.1, the optimal cut-off point was determined by ROC curve analysis. A multivariate analysis with optimal cut-off points was then performed. Results: A total of 71 BMBs were performed in 57 pts. None of the control biopsies in pts with normal CT and bone scan (10 of 10) contained tumor. A total of 46 of 61 BMBs (75.4%) were positive. 38 of 61 (62.3%) contained 50 or more cells. Prior treatments were docetaxel in 57 (79.2%) and abiraterone in 42 (58%) pts. Bisphosphonates had been used in 21 (28.8%) pts. The significant variables on univariate analysis were ALP more than or equal to 200 IU/L (p=0.059), prostate-specific antigen (PSA) more than or equal to 225 ng/mL (p=0.008), lactate dehydrogenase (LDH) more than or equal to 200 IU/L (p=0.09), mean HU more than or equal to 125 (p=0.000) and maximum HU more than or equal to 550 (p=0.001). These factors were tested in multivariate analysis. Only PSA and mean HU were significant in multivariate analysis. The combined PSA and mean HU score had an ROC AUC of 0.79. Conclusions: A combination of PSA and mean HU on CT could assist physicians in selecting APC patients/ iliac crest site more likely to have a positive BMB. Prospective evaluation is ongoing in a validation set.

Agreement among healthcare professionals in ten European countries in diagnosing case-vignettes of surgical-site infections

OBJECTIVE

Although surgical-site infection (SSI) rates are advocated as a major evaluation criterion, the reproducibility of SSI diagnosis is unknown. We assessed agreement in diagnosing SSI among specialists involved in SSI surveillance in Europe.

METHODS

Twelve case-vignettes based on suspected SSI were submitted to 100 infection-control physicians (ICPs) and 86 surgeons in 10 European countries. Each participant scored eight randomly-assigned case-vignettes on a secure online relational database. The intra-class correlation coefficient (ICC) was used to assess agreement for SSI diagnosis on a 7-point Likert scale and the kappa coefficient to assess agreement for SSI depth on a three-point scale.

RESULTS

Intra-specialty agreement for SSI diagnosis ranged across countries and specialties from 0.00 (95%CI, 0.00-0.35) to 0.65 (0.45-0.82). Inter-specialty agreement varied from 0.04 (0.00-0.62) in to 0.55 (0.37-0.74) in Germany. For all countries pooled, intra-specialty agreement was poor for surgeons (0.24, 0.14-0.42) and good for ICPs (0.41, 0.28-0.61). Reading SSI definitions improved agreement among ICPs (0.57) but not surgeons (0.09). Intra-specialty agreement for SSI depth ranged across countries and specialties from 0.05 (0.00-0.10) to 0.50 (0.45-0.55) and was not improved by reading SSI definition.

CONCLUSION

Among ICPs and surgeons evaluating case-vignettes of suspected SSI, considerable disagreement occurred regarding the diagnosis, with variations across specialties and countries.

Inter-hospital comparison of rates of surgical site infection following caesarean section delivery: evaluation of a multicentre surveillance study

BACKGROUND

Short postoperative stays following caesarean section delivery make it difficult to assess accurately the risk of surgical site infection (SSI). Methods of case-finding that minimize variation are required to support effective surveillance systems, especially where used for benchmarking.

AIM

To evaluate the efficacy of case-finding methods for SSI following caesarean delivery and their utility in establishing benchmark rates of SSI.

METHODS

Hospitals conducted surveillance over one or two 13-week periods. Patients were reviewed during their inpatient stay, post partum by community midwives and via patient questionnaire at 30 days post delivery. To estimate the reliability of case-finding methods, case-note reviews were undertaken in a random sample of four hospitals.

FINDINGS

A total of 404 SSIs were detected in 4107 caesarean deliveries from 14 hospitals. The median time to SSI was 10 days, 66% were detected in-hospital or by community midwives, and an additional 34% were patient-reported. The rate of SSI was 9.8% but the proportion of patients followed up varied significantly between centres. The estimated sensitivity and specificity of case-finding was 91.4% [95% confidence interval (CI): 53.4-98.4] and 98.6% (95% CI: 98.4-98.8), the positive predictive value 91.0% (95% CI: 82.4-96.1) and negative predictive value 98.6% (95% CI: 93.9-99.5).

CONCLUSIONS

Combined case ascertainment methods are a feasible way to achieve active post-discharge surveillance and had high negative and positive predictive values. Additional SSIs can be detected by patient questionnaires but rates of SSI were strongly influenced by variation in intensity of both healthcare worker- and patient-based case-finding. This factor must be taken into account when comparing or benchmarking rates of SSI.

Antitumour activity of docetaxel following treatment with the CYP17A1 inhibitor abiraterone: clinical evidence for cross-resistance?

BACKGROUND

Abiraterone and docetaxel are both approved treatments for men with metastatic castration-resistant prostate cancer (mCRPC). Abiraterone pre-docetaxel is currently undergoing evaluation in a phase III study. In vitro studies indicate that taxanes may act by disrupting androgen receptor signalling. We hypothesised that prior abiraterone exposure would adversely impact docetaxel efficacy.

PATIENTS AND METHODS

We retrospectively evaluated activity of docetaxel in mCRPC patients previously treated with abiraterone, using Prostate Cancer Working Group and radiological criteria.

RESULTS

Of the 54 patients treated with abiraterone, 35 subsequently received docetaxel. Docetaxel resulted in a prostate-specific antigen (PSA) decline of ≥50% in nine patients [26%, 95% confidence interval (CI) 13% to 43%], with a median time to PSA progression of 4.6 months (95% CI 4.2% to 5.9%). PSA declines ≥30% were achieved by 13 patients (37%, 95% CI 22% to 55%). The median overall survival was 12.5 months (95% CI 10.6-19.4). All patients who failed to achieve a PSA fall on abiraterone and were deemed abiraterone-refractory were also docetaxel-refractory (N = 8). In the 24 patients with radiologically evaluable disease, partial responses were reported in four patients (11%), none of whom were abiraterone-refractory.

CONCLUSION

The activity of docetaxel post-abiraterone appears lower than anticipated and no responses to docetaxel were observed in abiraterone-refractory patients.

Durable radiologic and clinical disease stability beyond PSA progression in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA)

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Background: AA, a potent oral CYP17A1 inhibitor is approved for treatment of mCRPC with a survival advantage of 4.9 months. In clinical practice, response evaluation remains challenging for pts with mCRPC. CTC conversion from CTC ≥ 5 to CTC < 5 with treatment predicts for improved overall survival in mCRPC. We hypothesized that pts continue to have durable disease stability beyond PSA progression on AA. Methods: Prostate Specific Antigen (PSA) responses, radiological responses and CTC conversion rates were retrospectively analysed in pts treated on AA at our institution. CTCs, PSA and imaging were obtained at predefined time points during these studies. Radiological and PSA progression were defined by standard Prostate Cancer Working Group Criteria II. Clinical progression consisted of worsening disease related pain, skeletal events or declining performance status.Pearson’s chi-squared test and the Kaplan-Meier method were used for this analysis. Results: 141 patients [ECOG Performance Status 0-2; Median Age: 69.7 (range 44.7-87.1); 85 post-docetaxel, 56 pre-docetaxel] received AA. The median duration of clinical and radiological stable disease (SD) was 16.8 months (n=55) and 5.6 months (n=75) in patients with a baseline CTCs count of ≤ 5 cells/7.5mls and ≥ 5 cells/7.5 mls respectively. In the 105 patients with documented PSA progression on AA there was a median 5.7-month delay in detecting radiological and/or clinical progression (95% CI: 4.2, 8.4; range 0.3, 35.6 months). Radiological and clinical SD of ≥ 1 year, ≥ 2 years and ≥ 3 years on AA was observed in 43/141 (30.5%), 21/141 (14.9%) and 12/141 (8.5%) respectively. Conclusions: Radiological and clinical disease stabilization beyond PSA progression is maintained in a high proportion of mCRPC patients treated with AA. Future studies should evaluate whether continued AA treatment beyond PSA and radiological progression can impact outcome.

Common genetic variation contributes significantly to the risk of childhood B-cell precursor acute lymphoblastic leukemia

Recent genome-wide association studies (GWAS) have provided the first unambiguous evidence that common genetic variation influences the risk of childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL), identifying risk single-nucleotide polymorphisms (SNPs) localizing to 7p12.2, 9p21.3, 10q21.2 and 14q11.2. The testing of SNPs individually for an association in GWA studies necessitates the imposition of a very stringent P-value to address the issue of multiple testing. While this reduces false positives, real associations may be missed and therefore any estimate of the total heritability will be negatively biased. Using GWAS data on 823 BCP-ALL cases by considering all typed SNPs simultaneously, we have calculated that 24% of the total variation in BCP-ALL risk is accounted for common genetic variation (95% confidence interval 6-42%). Our findings provide support for a polygenic basis for susceptibility to BCP-ALL and have wider implications for future searches for novel disease-causing risk variants.

Trends among pathogens reported as causing bacteraemia in England, 2004-2008

The Health Protection Agency in England operates a voluntary surveillance system that collects data on bacteraemias reported by over 90% of laboratories in England. Trends in causative microorganisms reported between 2004 and 2008 were analyzed using a generalized linear model with a log link function for Poisson distribution. In 2008, 101,276 episodes of bacteraemia were reported; a rate of 189 per 100,000 population. More than one-half occurred in those aged over 65 years and males. The most common organisms reported were Escherichia coli (23%), coagulase-negative staphylococci (CNS) (16.9%) and Staphylococcus aureus (11.4%). Between 2004 and 2008, E. coli bacteraemia increased by 33% (p < 0.001); the species now accounts for more than 30% of bacteraemia in those aged over 75 years. There also were significant increases in bacteraemia caused by other Gram-negative pathogens and marked seasonal variation. Bacteraemia caused by S. aureus increased until 2005, with a decline after 2006 (p < 0.001) entirely due to methicillin-resistant strains. CNS bacteraemia have declined significantly since 2007. The renewed dominance of Gram-negative pathogens as major causes of bacteraemia in England is of particular concern because they are associated with a high morbidity and increasing resistance to antibiotics. Further investigation of the underlying causes and prevention strategies is a public health priority. Recent declines in methicillin-resistant S. aureus bacteraemia have not been reflected in other pathogens, including methicillin-susceptible S. aureus.

Empirical treatment of influenza-associated pneumonia in primary care: a descriptive study of the antimicrobial susceptibility of lower respiratory tract bacteria (England, Wales and Northern Ireland, January 2007-March 2010)

OBJECTIVES

To determine the susceptibility of lower respiratory tract (LRT) isolates of Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae to antimicrobial agents recommended by UK guidelines for treatment of pneumonia associated with influenza-like illness.

METHODS

Analysis of antimicrobial susceptibility data from sentinel microbiology laboratories in England, Wales and Northern Ireland was carried out. Subjects comprised patients who had an LRT specimen taken in a general practitioner surgery or hospital outpatient setting between January 2007 and March 2010. The main outcome measurements were antimicrobial susceptibility trends of LRT isolates over time, between patient age groups and in different geographical regions.

RESULTS

Susceptibility to tetracyclines or co-amoxiclav was high. Of the 70,288 and 45,288 isolates with susceptibility results for tetracyclines or co-amoxiclav, 96% and 92%, respectively, were susceptible. Overall susceptibility to ciprofloxacin, ampicillin/amoxicillin and macrolides was lower than for tetracyclines or co-amoxiclav and varied markedly by organism. There were few clinically relevant variations in susceptibility to doxycycline or co-amoxiclav over time, geographically or between age groups.

CONCLUSIONS

The data support the use of doxycycline or co-amoxiclav as appropriate empiric treatment for LRT infection caused by the pathogens investigated, for patients in primary care.

THE PENETRATION OF AMMONIA INTO FROG MUSCLE

1. A study was made of the electrolyte changes which occur when frog muscles are immersed in a Ringer solution with 1/5 of the Na replaced by NH₄Cl. Analyses were made in the solution and in the muscles for K and NH₃, and the muscles were also analyzed for Cl, HCO₃, and Na. Control muscles were immersed in normal Ringer's solution and similarly analyzed. 2. The amount of ammonia taken up was about equal to the K and Na lost. There was also a small increase in chloride content. The bicarbonate content was the same in both experimental and control muscles, indicating no change in the muscle pH due to the NH₃ which penetrated. An increased loss of K due to the penetration of NH₃ was also demonstrated by the use of radioactive K. 3. After 5 hours, the concentration of ammonia per gram of muscle is about the same as the concentration in the solution. After 4 or 5 days, the concentration in the muscle is about 1.5 times that in the solution. The inside to outside NH₃ ratio is about equal to the corresponding H ion ratio, but is much less than the K ratio. 4. The rate of penetration of the NH₃ is increased by a rise of temperature, by stirring the solution, and by decrease in the concentration of Na, K, Ca, or Mg in the solution; it is decreased by increasing the size of the muscles or by killing them with chloroform or boiling. 5. Liver, smooth muscle, skin, and kidney, in a few experiments, behaved much like muscle except that there was a formation of urea in the case of liver. 6. The injection of NH₄Cl into anesthetized cats causes an increase in the level of K in the blood plasma.

Expanding CEP290 mutational spectrum in ciliopathies

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

Does a “one-stop” gynecology screening clinic for women in hereditary nonpolyposis colorectal cancer families have an impact on their psychological morbidity and perception of health?

Screening programs can reduce the burden of disease, however, they can be associated with raised levels of anxiety. The risk of endometrial and ovarian cancer is increased in hereditary nonpolyposis colorectal cancer (HNPCC). There is no prospective evidence to support screening for gynecological disease in HNPCC, however, current recommendations include the use of ultrasound and endometrial biopsy. This study assesses the impact of screening for gynecological cancer on self-reported symptoms of anxiety, depression, and perceptions of health. Women from HNPCC families attending gynecological screening (n= 26) completed the Hospital Anxiety and Depression Scale and the ShortForm36v2 questionnaires prior to screening with transvaginal ultrasound, outpatient/office hysteroscopy, endometrial biopsy, and ovarian tumor marker assessment (CA125). The same questionnaires were completed at 3 and 6 months following screening (15/26). Women in HNPCC families attending for gynecological screening did not have excess symptoms of anxiety or depression at baseline in subjective comparison to other populations. The process of screening and false positive screening results had no significant impact on symptoms of anxiety and depression or perceptions of health. We conclude that within the limitations of analysis in this small study group, screening for gynecological disease in HNPCC does not appear to be associated with any psychological morbidity.

The detection of microsatellite instability in blind endometrial samples--a potential novel screening tool for endometrial cancer in women from hereditary nonpolyposis colorectal cancer families?

Microsatellite instability (MSI) is the phenotypic molecular characteristic of the majority of tumors associated with the hereditary nonpolyposis colorectal cancer syndrome (HNPCC). Women in this group have an increased risk of endometrial cancer (EC). This study aimed to determine whether MSI could be demonstrated in blind endometrial samples from women with EC, HNPCC kindreds undergoing screening for EC, and women with normal endometrium. Twenty-four women with EC, 20 women from HNPCC kindreds, and 20 women undergoing gynecological surgery for benign indications underwent blind sampling. MSI analysis was performed by conventional polymerase chain reaction using fluorescent-labeled primers and automated analysis. Twelve microsatellites were studied with MSI defined as evident when novel alleles were seen in endometrial biopsy samples compared to genomic DNA. Of the 24 EC samples obtained, sufficient DNA for analysis was extracted in 17 cases. Three cases had evidence of MSI in at least 7/12 loci. None of the endometrium from the two other study groups revealed evidence of MSI. This is the first demonstration of MSI in blind endometrial biopsies. The ability to demonstrate MSI in heterogeneous endometrial samples suggests potential for the development of a novel EC screening tool for women in HNPCC kindreds.

Exploring the potential chemopreventative effect of aspirin and rofecoxib on hereditary nonpolyposis colorectal cancer-like endometrial cancer cells in vitro through mechanisms involving apoptosis, the cell cycle, and mismatch repair gene expression

Women in hereditary nonpolyposis colorectal cancer (HNPCC) families have up to a 71% lifetime risk for developing endometrial cancer (EC). This compares to the female lifetime risk for colorectal cancer (CRC) in HNPCC of 60%. The basis of HNPCC is an inherited mutation in a mismatch repair gene (MMR). Aspirin and COX2 inhibitors seem to have a chemoprotective effect on CRC in the general population and are the subject of prospective clinical studies in patients at high risk for CRC including HNPCC. There is no evidence that these agents have any protective effect against EC in the general population. This study investigated the effect of aspirin and a COX2 inhibitor (rofecoxib) on an HNPCC EC cell line model (Ishikawa) by assessing the effect on proliferation, apoptosis, the cell cycle, and MMR gene expression. Aspirin inhibits EC cell proliferation by inducing apoptosis and changes in the cell cycle. This effect is not mediated by changes in MMR gene (hMSH2) expression as assessed by quantitative reverse transcription-polymerase chain reaction. Rofecoxib inhibits EC cell proliferation; this did not appear to be mediated by induction of apoptosis, by alterations of the cell cycle, or by changes in MMR gene expression.

Reduced bone mineral density and hyaloid vasculature remnants in a consanguineous recessive FEVR family with a mutation in LRP5

BACKGROUND/AIMS

Familial exudative vitreoretinopathy (FEVR) is an inherited blinding condition characterised by abnormal development of the retinal vasculature. FEVR has multiple modes of inheritance, and homozygous mutations in LRP5 have recently been reported as underlying the recessive form of this disease. The aim of this study was to examine LRP5 in a consanguineous recessive FEVR family and to clarify the eye and bone phenotype associated with recessive FEVR.

METHODS

All family members were examined by slit lamp biomicroscopy and indirect ophthalmoscopy. Linkage to LRP5 was determined by genotyping microsatellite markers, constructing haplotypes and calculating lod scores. Mutation screening of LRP5 was performed by polymerase chain reaction amplification of genomic DNA followed by direct sequencing. Bone mineral density (BMD) was evaluated in all family members using dual energy x ray absorptiometry (DEXA).

RESULTS

The clinical features observed in this family were consistent with a diagnosis of recessive FEVR. A homozygous LRP5 missense mutation, G550R, was identified in all affected individuals and all unaffected family members screened were heterozygous carriers of this mutation. Reduced BMD, hyaloid vasculature remnants, and nystagmus were features of the phenotype.

CONCLUSION

Recessive mutations in LRP5 can cause FEVR with reduced BMD and hyaloid vasculature remnants. Assessment of a patient with a provisional diagnosis of FEVR should therefore include investigation of BMD, with reduced levels suggestive of an underlying LRP5 mutation.

A nonsense mutation in the first transmembrane domain of connexin 43 underlies autosomal recessive oculodentodigital syndrome

BACKGROUND

Oculodentodigital syndrome (ODD) is a pleiotropic congenital disorder characterised by abnormalities of the face, eyes, dentition, and limbs. ODD, which is inherited as an autosomal dominant trait, results from missense mutations in the gap junction protein connexin 43.

OBJECTIVE

To analyse a family with a history of ODD which is inherited in an autosomal recessive manner

RESULTS

ODD in this family resulted from the homozygous mutation R33X in the first transmembrane domain of connexin 43.

CONCLUSIONS

The findings provide clear genetic evidence that ODD can be inherited in an autosomal recessive manner and that a dominant negative mechanism underlies autosomal dominant ODD.