Clustering properties of the cardiac ryanodine receptor in health and heart failure.

The cardiac ryanodine receptor (RyR2) is an intracellular Ca2+ release channel vital for the function of the heart. Physiologically, RyR2 is triggered to release Ca2+ from the sarcoplasmic reticulum (SR) which enables cardiac contraction; however, spontaneous Ca2+ leak from RyR2 has been implicated in the pathophysiology of heart failure (HF). RyR2 channels have been well documented to assemble into clusters within the SR membrane, with the organisation of RyR2 clusters recently gaining interest as a mechanism by which the occurrence of pathological Ca2+ leak is regulated, including in HF. In this review, we explain the terminology relating to key nanoscale RyR2 clustering properties as both single clusters and functionally grouped Ca2+ release units, with a focus on the advancements in super-resolution imaging approaches which have enabled the detailed study of cluster organisation. Further, we discuss proposed mechanisms for modulating RyR2 channel organisation and the debate regarding the potential impact of cluster organisation on Ca2+ leak activity. Finally, recent experimental evidence investigating the nanoscale remodelling and functional alterations of RyR2 clusters in HF is discussed with consideration of the clinical implications.

Direct regulation of the cardiac ryanodine receptor (RyR2) by O-GlcNAcylation.

BACKGROUND: O-GlcNAcylation is the enzymatic addition of a sugar, O-linked ß-N-Acetylglucosamine, to the serine and threonine residues of proteins, and is abundant in diabetic conditions. We have previously shown that O-GlcNAcylation can trigger arrhythmias by indirectly increasing pathological Ca2+ leak through the cardiac ryanodine receptor (RyR2) via Ca2+/calmodulin-dependent kinase II (CaMKII). However, RyR2 is well known to be directly regulated by other forms of serine and threonine modification, therefore, this study aimed to determine whether RyR2 is directly modified by O-GlcNAcylation and if this also alters the function of RyR2 and Ca2+ leak. METHODS: O-GlcNAcylation of RyR2 in diabetic human and animal hearts was determined using western blotting. O-GlcNAcylation of RyR2 was pharmacologically controlled and the propensity for Ca2+ leak was determined using single cell imaging. The site of O-GlcNAcylation within RyR2 was determined using site-directed mutagenesis of RyR2. RESULTS: We found that RyR2 is modified by O-GlcNAcylation in human, animal and HEK293 cell models. Under hyperglycaemic conditions O-GlcNAcylation was associated with an increase in Ca2+ leak through RyR2 which persisted after CaMKII inhibition. Conversion of serine-2808 to alanine prevented an O-GlcNAcylation induced increase in Ca2+ leak. CONCLUSIONS: These data suggest that the function of RyR2 can be directly regulated by O-GlcNAcylation and requires the presence of serine-2808.

Depressed HCN4 function in the type 2 diabetic sinoatrial node.

Diabetic patients often have impaired heart rate (HR) control. HR is regulated both intrinsically within the sinoatrial node (SAN) and via neuronal input. Previously, we found lower ex vivo HR in type 2 diabetic rat hearts, suggesting impaired HR generation within the SAN. The major driver of pacemaking within the SAN is the activity of hyperpolarisation-activated cyclic nucleotide-gated 4 (HCN(4)) channels. This study aimed to investigate whether the lower intrinsic HR in the type 2 diabetic heart is due to changes in HCN4 function, protein expression and/ or distribution. The intrinsic HR response to HCN4 blockade was determined in isolated Langendorff-perfused hearts of Zucker type 2 Diabetic Fatty (ZDF) rats (DM) and their non-diabetic ZDF littermates (nDM). HCN4 protein expression and membrane localisation were determined using western blot and immunofluorescence, respectively. We found that the intrinsic HR was lower in DM compared to nDM hearts. The change in intrinsic HR in response to HCN4 blockade with ivabradine was diminished in DM hearts, which normalised the intrinsic HR between the groups. HCN4 protein expression was decreased in the SAN of DM compared to nDM controls with no change in the fraction of HCN4 localised to the membrane of SAN cardiomyocytes. The lower intrinsic HR in DM is likely due to decreased HCN4 expression and depressed HCN4 function. Our study provides a novel understanding into the intrinsic mechanisms underlying altered HR control in type 2 diabetes.

Junctophilin-2 in the nanoscale organisation and functional signalling of ryanodine receptor clusters in cardiomyocytes.

Signalling nanodomains requiring close contact between the plasma membrane and internal compartments, known as 'junctions', are fast communication hubs within excitable cells such as neurones and muscle. Here, we have examined two transgenic murine models probing the role of junctophilin-2, a membrane-tethering protein crucial for the formation and molecular organisation of sub-microscopic junctions in ventricular muscle cells of the heart. Quantitative single-molecule localisation microscopy showed that junctions in animals producing above-normal levels of junctophilin-2 were enlarged, allowing the re-organisation of the primary functional protein within it, the ryanodine receptor (RyR; in this paper, we use RyR to refer to the myocardial isoform RyR2). Although this change was associated with much enlarged RyR clusters that, due to their size, should be more excitable, functionally it caused a mild inhibition in the Ca2+ signalling output of the junctions (Ca2+ sparks). Analysis of the single-molecule densities of both RyR and junctophilin-2 revealed an ∼3-fold increase in the junctophilin-2 to RyR ratio. This molecular rearrangement is compatible with direct inhibition of RyR opening by junctophilin-2 to intrinsically stabilise the Ca2+ signalling properties of the junction and thus the contractile function of the cell.

Early transverse tubule development begins in utero in the sheep heart.

The ventricular cardiomyocytes of adult mammals contain invaginations of the plasma membrane known as transverse (t)-tubules. These regular structures are essential for the synchronisation of excitation-contraction (EC) coupling throughout the cell, which is a vital process for cardiac function. T-tubules form a close association with the sarcoplasmic reticulum (SR) to form junctions, where several key proteins involved in EC coupling are localised, including the SR calcium release channels-the ryanodine receptors (RyR). The lipophilic SR protein junctophilin-2 (JPH2) has been implicated in the development of both the junctions and t-tubules. Several studies have identified that t-tubules develop only postnatally in rodents, while historical electron microscopy data indicate that this is not the case in larger mammals, including humans. We have performed, to our knowledge, the first fluorescent, target-specific study to characterise t-tubule development in the large mammalian fetal heart, focussing on the sheep. T-tubules were present in fetal sheep hearts from 114 days gestation (with term being 145 days), with occurrence progressively increasing with gestational age, and further maturation after birth. This was accompanied by an increasing intracellular localisation of JPH2, which progressively increased its association with RyR within the cardiomyocytes as they undergo hypertrophy. These findings indicate that large mammalian hearts exhibit a significantly different temporal pattern of development compared to that of the rodent. Our findings have potential implications for human cardiac development, including the future investigation of congenital heart disease.

A case series study on the effect of Ebola on facility-based deliveries in rural Liberia.

BACKGROUND: As communities' fears of Ebola virus disease (EVD) in West Africa exacerbate and their trust in healthcare providers diminishes, EVD has the potential to reverse the recent progress made in promoting facility-based delivery. Using retrospective data from a study focused on maternal and newborn health, this analysis examined the influence of EVD on the use of facility-based maternity care in Bong Country, Liberia, which shares a boarder with Sierra Leone - near the epicenter of the outbreak. METHODS: Using a case series design, retrospective data from logbooks were collected at 12 study sites in one county. These data were then analyzed to determine women's use of facility-based maternity care between January 2012 and October 2014. The primary outcome was the number of facility-based deliveries over time. The first suspected case of EVD in Bong County was reported on June 30, 2014. Heat maps were generated and the number of deliveries was normalized to the average number of deliveries during the full 12 months before the EVD outbreak (March 2013 - February 2014). RESULTS: Prior to the EVD outbreak, facility-based deliveries steadily increased in Bong County reaching an all-time high of over 500 per month at study sites in the first half of 2014 - indicating Liberia was making inroads in normalizing institutional maternal healthcare. However, as reports of EVD escalated, facility-based deliveries decreased to a low of 113 in August 2014. CONCLUSION: Ebola virus disease has negatively impacted the use of facility-based maternity services, placing childbearing women at increased risk for morbidity and death.

Texting From the Bush: Data Collection Using SMS Text Messaging in Areas of Low Network Coverage From Low-Literacy Providers.

Mobile health technology, specifically Short Message Service (SMS), provides a low-cost medium to transmit data in real time. SMS has been used for data collection by highly literate and educated health care workers in low-resource countries; however, no previous studies have evaluated implementation of an SMS intervention by low-literacy providers. The Liberian Ministry of Health and Social Welfare identified a lack of accurate data on the number of pregnancies from rural areas. To capture these data from 11 rural communities in Liberia, 66 low-literate traditional midwives and 15 high-literate certified midwives were trained to report data via SMS. Data were reported via a 9-digit code sent from Java-based mobile phones. Study aims included determining the following components of SMS transmission: success rate, accuracy, predictors of successful transmission, and acceptance. Success rate of SMS transmission was significantly higher for certified midwives than for traditional midwives. The error rate was significantly higher for traditional midwives than for certified midwives. Years of education was the only predictor of successful SMS transmission. Traditional midwives and certified midwives accepted the intervention, although certified midwives found it easier to use. Certified midwives performed significantly better than did traditional midwives. SMS texting interventions should be targeted to health care workers with higher rates of literacy.

Outcomes of anatomic shoulder arthroplasty in primary osteoarthritis in type B glenoids.

BACKGROUND: Primary glenohumeral osteoarthritis with posterior wear of the glenoid and posterior subluxation of the humerus (Walch type B) presents a challenge to the treating surgeon. Our hypothesis was that glenoids with biconcavity (B2) would be associated with worse outcomes (functional scores and complications) than B1 glenoids. MATERIALS AND METHODS: We retrospectively analyzed prospectively collected data on 112 anatomic total shoulder arthroplasties (104 patients) with B glenoids. Preoperative computed tomography identified 64 B1 glenoids and 48 B2 glenoids (50 and 37 available for follow-up). RESULTS: A significant difference between B1 and B2 glenoids was noted in average retroversion (11° vs. 16°; P < .001) and average posterior humeral subluxation (65% vs. 75%; P < .001). No significant difference was seen in mean age (69.5 vs. 69.2 years) or body mass index (28.5 vs. 27.4) at time of surgery. At average follow-up of 60 months (range, 23-120 months), glenoid component radiolucencies (51.6%, B1; 47.9%, B2), range of motion, preoperative and postoperative scores of the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire, and patient satisfaction were not significantly different between the 2 groups. Four revisions (4.6%) were documented for acute postoperative infection (2.3%), subscapularis failure (1.1%), and glenoid loosening (1.1%). CONCLUSIONS: Although biconcave glenoids commonly have more severe retroversion and posterior subluxation of the humerus, we were unable to find a clinical or radiographic difference in outcome of patients with B1 or B2 glenoids treated with anatomic total shoulder arthroplasty at intermediate-term follow-up. Continued clinical and radiographic follow-up of these cohorts will be necessary to assess any future divergence in outcome.

Reduced junctional Na+/Ca2+-exchanger activity contributes to sarcoplasmic reticulum Ca2+ leak in junctophilin-2-deficient mice.

Expression silencing of junctophilin-2 (JPH2) in mouse heart leads to ryanodine receptor type 2 (RyR2)-mediated sarcoplasmic reticulum (SR) Ca(2+) leak and rapid development of heart failure. The mechanism and physiological significance of JPH2 in regulating RyR2-mediated SR Ca(2+) leak remains elusive. We sought to elucidate the role of JPH2 in regulating RyR2-mediated SR Ca(2+) release in the setting of cardiac failure. Cardiac myocytes isolated from tamoxifen-inducible conditional knockdown mice of JPH2 (MCM-shJPH2) were subjected to confocal Ca(2+) imaging. MCM-shJPH2 cardiomyocytes exhibited an increased spark frequency width with altered spark morphology, which caused increased SR Ca(2+) leakage. Single channel studies identified an increased RyR2 open probability in MCM-shJPH2 mice. The increase in spark frequency and width was observed only in MCM-shJPH2 and not found in mice with increased RyR2 open probability with native JPH2 expression. Na(+)/Ca(2+)-exchanger (NCX) activity was reduced by 50% in MCM-shJPH2 with no detectable change in NCX expression. Additionally, 50% inhibition of NCX through Cd(2+) administration alone was sufficient to increase spark width in myocytes obtained from wild-type mice. Additionally, superresolution analysis of RyR2 and NCX colocalization showed a reduced overlap between RyR2 and NCX in MCM-shJPH2 mice. In conclusion, decreased JPH2 expression causes increased SR Ca(2+) leakage by directly increasing open probability of RyR2 and by indirectly reducing junctional NCX activity through increased dyadic cleft Ca(2+). This demonstrates two novel and independent cellular mechanisms by which JPH2 regulates RyR2-mediated SR Ca(2+) leak and heart failure development.

Tools for detection of Mycoplasma amphoriforme: a primary respiratory pathogen?

Mycoplasma amphoriforme is a recently described organism isolated from the respiratory tracts of patients with immunodeficiency and evidence of chronic infection. Novel assays for the molecular detection of the organism by real-time quantitative PCRs (qPCRs) targeting the uracil DNA glycosylase gene (udg) or the 23S rRNA gene are described here. The analytical sensitivities are similar to the existing conventional M. amphoriforme 16S rRNA gene PCR, with the advantage of being species specific, rapid, and quantitative. By using these techniques, we demonstrate the presence of this organism in 17 (19.3%) primary antibody-deficient (PAD) patients, 4 (5%) adults with lower respiratory tract infection, 1 (2.6%) sputum sample from a patient attending a chest clinic, and 23 (0.21%) samples submitted for viral diagnosis of respiratory infection, but not in normal adult control subjects. These data show the presence of this microorganism in respiratory patients and suggest that M. amphoriforme may infect both immunocompetent and immunocompromised people. Further studies to characterize this organism are required, and this report provides the tools that may be used by other research groups to investigate its pathogenic potential.

Second generation HIV surveillance in Pakistan: policy challenges and opportunities.

From 2004 to 2011, the Canada-Pakistan HIV/AIDS Surveillance Project (HASP) worked with government and non-government partners in Pakistan to design and implement an HIV second generation surveillance (SGS) system. Insights into the development of scalable cost effective surveillance methodologies, implementation, use of data for HIV prevention and human rights were gained over the course of HASP. An ideal SGS system would be affordable, able to be implemented independently by local partners and produce data that could be readily applied in policy and programmes. Flexibility in design and implementation is important to ensure that any SGS system is responsive to information needs, political changes and changes in key population dynamics and HIV epidemics. HASP's mapping methodology is innovative and widely accepted as best practice, but sustainability of the SGS system it developed is a challenge.

Translating knowledge from Pakistan's second generation surveillance system to other global contexts.

BACKGROUND: From 2004 to 2011, a collaborative project was undertaken to enhance the capacity of the Government of Pakistan to implement an effective second-generation surveillance system for HIV/AIDS, known as the HIV/AIDS Surveillance Project (HASP). In four separate rounds, behavioural questionnaires were administered among injection drug users, and female, male and hijra (transgender) sex workers. Dried blood spots were collected for HIV testing. METHODS: Through interviews with project staff in Pakistan and Canada, we have undertaken a critical review of the role of HASP in generating, using and translating knowledge, with an emphasis on capacity building within both the donor and recipient countries. We also documented ongoing and future opportunities for the translation of knowledge produced through HASP. RESULTS: Knowledge translation activities have included educational workshops and consultations held in places as diverse as Colombia and Cairo, and the implementation of HASP methodologies in Asia, the Middle East and sub-Saharan Africa. HASP methodologies have been incorporated in multiple WHO reports. Importantly, the donor country, Canada, has benefited in significant ways from this partnership. Operational and logistical lessons from HASP have, in turn, improved how surveillance is performed in Canada. Through this project, significant capacity was built among the staff of HASP, non-governmental organisations which were engaged as implementation partners, data coordination units which were established in each province, and in the laboratory. As is to be expected, different organisations have different agendas and priorities, requiring negotiation, at times, to ensure the success of collaborative activities. Overall, there has been considerable interest in and opportunities made for learning about the methodologies and approaches employed by HASP. CONCLUSIONS: Generally, the recognition of the strengths of the approaches and methodologies used by HASP has ensured an appetite for opportunities of mutual learning.

Patient-centered communication and health assessment with youth.

BACKGROUND: Patient-centered communication is fundamental to individualizing healthcare, but there has been limited evaluation of provider communication with youth. OBJECTIVES: The aim was to compare communication outcomes after use of an event history calendar (EHC) and Guidelines for Adolescent Preventive Services (GAPS) to structure interactions during a clinic visit. Patient and provider descriptions of EHC and GAPS communication experiences were also obtained. METHODS: This is a secondary analysis of data obtained during a randomized controlled trial. A sequential explanatory mixed-methods approach was used. A split-plot design with one between factor (EHC, GAPS) and one within factor (pretest, posttest) was used for the quantitative portion. Qualitative data were collected from open-ended questions, audiotaped visits, and exit interviews. Providers (n = 9) at three clinics were assigned at random and trained to implement either the EHC or GAPS protocol. Male and female youth (n = 186) were randomly assigned to the EHC or GAPS intervention. Before their clinic visit, youth completed assessments of past communication experiences with healthcare providers (pretest); communication during the current visit was assessed immediately after the visit (posttest). RESULTS: Communication outcomes from pretest to posttest improved for youth in both the EHC and GAPS groups. Post hoc subgroup analysis suggested that men and Arab Americans derived more benefit from the EHC intervention in some aspects of communication. Qualitatively, the EHC group identified improved outcomes in validating patient perspective, being viewed in context, reaching a shared understanding of needs and preferences, and being helped to share power in the healthcare interaction. DISCUSSION: EHC and GAPS provided effective frameworks for structuring communication during a clinic visit. Compared with GAPS, the integrated time-linked assessment captured by the EHC enhanced patient-centered communication in select groups.

Lessons learned in Liberia: preliminary examination of the psychometric properties of trust and teamwork among maternal healthcare workers.

BACKGROUND: Post-conflict Liberia has one of the fastest growing populations on the continent and one of the highest maternal mortality rates among the world. However, in the rural regions, less than half of all births are attended by a skilled birth attendant. There is a need to evaluate the relationship between trained traditional healthcare providers and skilled birth attendants to improve maternal health outcomes. This evaluation must also take into consideration the needs and desires of the patients. The purpose of this pilot study was to establish the validity and reliability of a survey tool to evaluate trust and teamwork in the working relationships between trained traditional midwives and certified midwives in a post-conflict country. METHODS: A previously established scale, the Trust and Teambuilding Scale, was used with non- and low-literate trained traditional midwives (n=48) in rural Liberia to evaluate trust and teamwork with certified midwives in their communities. Initial results indicated that the scale and response keys were culturally inadequate for this population. A revised version of the scale, the Trust and Teamwork Scale - Liberia, was created and administered to an additional group of non- and low-literate, trained traditional midwives (n=42). Exploratory factor analysis using Mplus for dichotomous variables was used to determine the psychometric properties of the revised scale and was then confirmed with the full sample (n=90). Additional analyses included contrast validity, convergent validity, and Kuder-Richardson reliability. RESULTS: Exploratory factor analysis revealed two factors in the revised Trust and Teamwork Scale - Liberia. These two factors, labeled trust and teamwork, included eleven of the original eighteen items used in the Trust and Teamwork Scale and demonstrated contrast and convergent validity and adequate reliability. CONCLUSIONS: The revised scale is suitable for use with non- and low-literate, trained traditional midwives in rural Liberia. Continued cross-cultural validation of tools is essential to ensure scale adequacy across populations. Future work should continue to evaluate the use of the Trust and Teamwork Scale - Liberia across cultures and additional work is needed to confirm the factor structure.

In search of an adult attachment stress provocation to measure effect on the oxytocin system: a pilot validation study.

BACKGROUND: Oxytocin is a promising biomarker for psychiatric conditions arising from early relational trauma, childhood maltreatment, and attachment dysregulation, including posttraumatic stress and dissociative disorders. OBJECTIVE: This exploratory pilot study examined plasma oxytocin as a biomarker for alterations in the attachment system. DESIGN: We used a single group, repeated-measures design with 15 women. The protocol used a film clip previously validated as a provocation to the hypothalamic-pituitary-adrenal axis. RESULTS: The repeated-measures ANOVA showed differences in oxytocin across the three time points. Correlations with oxytocin indicated that measures of dissociation and somatization correlated most strongly with higher levels of oxytocin measured during exposure to the film's bonding scene and posttraumatic stress disorder correlated most strongly with lower levels at the film's abandonment scene. Post hoc analyses revealed differences in oxytocin response related to psychopathology. CONCLUSION: Replication studies should characterize participants on a range of psychiatric conditions associated with attachment dysregulation.

Cell phones to collect pregnancy data from remote areas in Liberia.

PURPOSE: To report findings on knowledge and skill acquisition following a 3-day training session in the use of short message service (SMS) texting with non- and low-literacy traditional midwives. DESIGN: A pre- and post-test study design was used to assess knowledge and skill acquisition with 99 traditional midwives on the use of SMS texting for real-time, remote data collection in rural Liberia, West Africa. METHODS: Paired sample t-tests were conducted to establish if overall mean scores varied significantly from pre-test to immediate post-test. Analysis of variance was used to compare means across groups. The nonparametric McNemar's test was used to determine significant differences between the pre-test and post-test values of each individual step involved in SMS texting. Pearson's chi-square test of independence was used to examine the association between ownership of cell phones within a family and achievement of the seven tasks. FINDINGS: The mean increase in cell phone knowledge scores was 3.67, with a 95% confidence interval ranging from 3.39 to 3.95. Participants with a cell phone in the family did significantly better on three of the seven tasks in the pre-test: "turns cell on without help" (χ(2) (1) = 9.15, p= .003); "identifies cell phone coverage" (χ(2) (1) = 5.37, p= .024); and "identifies cell phone is charged" (χ(2) (1) = 4.40, p= .042). CONCLUSIONS: A 3-day cell phone training session with low- and nonliterate traditional midwives in rural Liberia improved their ability to use mobile technology for SMS texting. CLINICAL RELEVANCE: Mobile technology can improve data collection accessibility and be used for numerous health care and public health issues. Cell phone accessibility holds great promise for collecting health data in low-resource areas of the world.

Comprehensive care and pregnancy: the unmet care needs of pregnant women with a history of rape.

This paper proposes a framework for assessing the unmet needs of rape survivors during pregnancy based on the Sexual Assault Nurse Examiner (SANE) practice level theory and an empirical exploration of rape survivors' health status in pregnancy via a secondary analysis. Our findings indicate that there may be unmet needs in pregnancy related to all five post-assault comprehensive care components: (1) physical care, (2) pregnancy prevention, (3) sexually transmitted infection screening, (4) psychological care, and (5) legal care. Rape history and its current impact on the survivor predicted somatic disorders, substance use, unwanted pregnancy, infections, posttraumatic stress disorder, and recent abuse.

The function and regulation of calsequestrin-2: implications in calcium-mediated arrhythmias.

Cardiac arrhythmias are life-threatening events in which the heart develops an irregular rhythm. Mishandling of Ca2+ within the myocytes of the heart has been widely demonstrated to be an underlying mechanism of arrhythmogenesis. This includes altered function of the ryanodine receptor (RyR2)-the primary Ca2+ release channel located to the sarcoplasmic reticulum (SR). The spontaneous leak of SR Ca2+ via RyR2 is a well-established contributor in the development of arrhythmic contractions. This leak is associated with increased channel activity in response to changes in SR Ca2+ load. RyR2 activity can be regulated through several avenues, including interactions with numerous accessory proteins. One such protein is calsequestrin-2 (CSQ2), which is the primary Ca2+-buffering protein within the SR. The capacity of CSQ2 to buffer Ca2+ is tightly associated with the ability of the protein to polymerise in response to changing Ca2+ levels. CSQ2 can itself be regulated through phosphorylation and glycosylation modifications, which impact protein polymerisation and trafficking. Changes in CSQ2 modifications are implicated in cardiac pathologies, while mutations in CSQ2 have been identified in arrhythmic patients. Here, we review the role of CSQ2 in arrhythmogenesis including evidence for the indirect and direct regulation of RyR2 by CSQ2, and the consequences of a loss of functional CSQ2 in Ca2+ homeostasis and Ca2+-mediated arrhythmias. Supplementary Information: The online version contains supplementary material available at 10.1007/s12551-021-00914-6.

Psychometric testing of the decisional conflict scale: genetic testing hereditary breast and ovarian cancer.

BACKGROUND: : Hereditary breast and ovarian cancer (HBOC) syndrome is attributed mostly to mutations in the Breast Cancer 1 and Breast Cancer 2 genes (BRCA1/2). Mutation carriers of BRCA1/2 genes have significantly higher risk for developing breast cancer compared with the general population (55%-85% vs. 12%) and for developing ovarian cancer (20%-60% vs. 1.5%). The availability of genetic testing enables mutation carriers to make informed decisions about managing their cancer risk (e.g., risk-reducing surgery). However, uptake of testing for HBOC among high-risk individuals is low, indicating the need to better understand and measure the decisional conflict associated with this process. OBJECTIVE: : The aim of this study was to evaluate the reliability and validity of the modified Decisional Conflict Scale for use in decisions associated with genetic testing for HBOC. METHODS: : This cross-sectional cohort study, recruited women who pursued genetic testing for HBOC in two genetic risk assessment clinics affiliated with a large comprehensive cancer center and one of their female relatives who did not pursue testing. The final sample consisted of 342 women who completed all 16 items of the Decisional Conflict Scale. The psychometric properties of the scale were assessed using tests of reliability and validity, including face, content, construct, contrast, convergent, divergent, and predictive validity. RESULTS: : Factor analysis using principal axis factoring with oblimin rotation elicited a three-factor structure: (a) Lack of Knowledge About the Decision (α = .97), (b) Lack of Autonomy in Decision Making (α = .94), and (c) Lack of Confidence in Decision Making (α = .87). These factors explained 82% of the variance in decisional conflict about genetic testing. Cronbach's alpha coefficient was .96. DISCUSSION: : The instrument is an important tool for researchers and healthcare providers working with women at risk for HBOC who are deciding whether genetic testing is the right choice for them.