An overview of the impact of rare disease characteristics on research methodology

Descriptive epidemiology demonstrating the All of Us database as a versatile resource for the rare and undiagnosed disease community

OBJECTIVE

We aim to demonstrate the versatility of the All of Us database as an important source of rare and undiagnosed disease (RUD) data, because of its large size and range of data types.

MATERIALS AND METHODS

We searched the public data browser, electronic health record (EHR), and several surveys to investigate the prevalence, mental health, healthcare access, and other data of select RUDs.

RESULTS

Several RUDs have participants in All of Us [eg, 75 of 100 rare infectious diseases (RIDs)]. We generated health-related data for undiagnosed, sickle cell disease (SCD), cystic fibrosis (CF), and infectious (2 diseases) and chronic (4 diseases) disease pools.

CONCLUSION

Our results highlight the potential value of All of Us with both data breadth and depth to help identify possible solutions for shared and disease-specific biomedical and other problems such as healthcare access, thus enhancing diagnosis, treatment, prevention, and support for the RUD community.

Management of rare and undiagnosed diseases: insights from researchers and healthcare professionals in Türkiye

Introduction

Diagnosis, treatment and management of rare diseases (RD) pose unique challenges due to their complex nature, significantly impacting the daily experiences of researchers and healthcare professionals working in this field. Despite increasing awareness and progress in the field of RD worldwide in recent years, a significant gap remains in our understanding of the specific barriers that these professionals face in their work with RD. This study provides a detailed survey analysis that sheds light on the challenges that researchers and healthcare professionals face in diagnosing, treating, managing and conducting research on RD.

Methods

We developed a national online survey with three RD stakeholder groups (Researchers, Healthcare professionals and researcher-healthcare professionals) to identify the main challenges and needs in Türkiye for the diagnosis, treatment and follow-up processes of rare and undiagnosed diseases.

Results

The survey was completed by 363 participants, revealing that participants face key challenges such as the need to refer patients to specialized centers, financial burdens, limited access to necessary tests, inadequate support for rare disease research and a lack of interdisciplinary collaboration. Participants also noted that RD are inherently difficult to conduct research on with small cohorts. Survey results also suggest a number of policy improvements to accelerate research on RD: increased funding, establishment of robust surveillance systems, and development of comprehensive national action plans and guidelines on RD.

Discussion

To the best of our knowledge, this is the first study to be conducted in Türkiye. This study contributes to the understanding of the needs of professionals in rare disease research and highlights the urgent need for system improvements to support them.

The link between traumatic stress and autoimmune rheumatic diseases: A systematic scoping review

BACKGROUND

The impact of traumatic stress on autoimmune rheumatic diseases (ARDs) has been largely overlooked in existing research. This scoping review aimed to systematically examine the research literature relating to the relationship between traumatic stress and ARDs, by identifying study designs, methodologies, and gaps in the current research landscape.

METHODS

The following databases and search interfaces were searched on 15th December 2023: Embase (via Embase.com), Medline (via PubMed), and Web of Science. Additional references were identified via bibliographies of included studies. The following studies were included, with no publication date limit and language restricted to English: targeting the association between traumatic stress and ARDs, observational methodologies, including cohort, case-control, and cross-sectional studies, exclusively focusing on self-reported psychological trauma impacts, such as adverse childhood experiences (ACEs), Post-traumatic Stress Disorder (PTSD), or major life stressors. Two authors independently assessed the studies for inclusion criteria and extracted the data.

RESULTS

This scoping review revealed connections between traumatic stress and ARDs through an analysis of 21 included studies, highlighting the scarcity of research in this area. The studies, primarily from high-income countries and especially the USA, span from 2000 to 2023, indicating a growing interest in recent years and employing a range of methodologies. Traumas such as ACEs, PTSD, and major life events were frequently examined, showing a strong association with an increased risk and severity of ARDs, particularly rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

CONCLUSION

This scoping review reveals a notable dearth in research on the impact of traumatic stress, such as ACEs, PTSD, and major life events, on ARDs, especially on rare diseases, yet underscores a significant association between trauma and ARD severity or incidence. It highlights the critical need for future investigations to broaden the scope of ARDs studied, extend research to less represented regions, and utilize diverse, standardized methodologies to deepen our understanding of the trauma-ARD association.

Prevalence rates for ectodermal dysplasia syndromes

BACKGROUND

Ectodermal dysplasias (EDs) are a heterogeneous group of genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. There are currently 49 recognized EDs with molecularly confirmed etiology. The EDs are very rare disorders, individually and in aggregate. Very little is published regarding the prevalence of these rare disorders. As a result of the genomics revolution, rare diseases have emerged as a global health priority. The various disabilities arising from rare disorders, as well as diagnostic and treatment uncertainty, have been demonstrated to have detrimental effects on the health, psychosocial, and economic aspects of families affected by rare disorders. Contemporary research methodologies and databases can address what have been historic challenges encountered when conducting research on rare diseases.

OBJECTIVE

In this study, we aim to ascertain period prevalence rates for several of the more common ectodermal dysplasia syndromes, by querying a large multicenter database of electronic health records, Oracle Real-World Data.

METHODS

For each of the included ectodermal dysplasia syndromes a clinical definition was developed by a committee of international experts with interests in EDs. The clinical definitions were based upon a combination of clinical features and designated by ICD-9 and ICD-10 codes. The January 2023 version of the Oracle Real-World Data database was queried for medical records that coincided with the clinical definitions. For our study, there were 64,523,460 individual medical records queried.

RESULTS

Period prevalence rates were calculated for the following ED disorders: hypohidrotic ectodermal dysplasia, found to be 2.99 per 100,000; ectodermal dysplasia and immunodeficiency 1, 0.23 per 100,000; Clouston syndrome, 0.15 per 100,000; ectrodactyly ectodermal dysplasia and cleft lip/palate syndrome, 0.61 per 100,000; ankyloblepharon-ectodermal defects-cleft lip/palate syndrome, 0.36 per 100,000; focal dermal hypoplasia, 0.10 per 100,000; and incontinentia pigmenti, 0.88 per 100,000.

CONCLUSION

This study established estimated period prevalence rates for several of the ectodermal dysplasia syndromes, and it demonstrated the feasibility of utilizing large multicenter databases of electronic health records, such as Oracle Real World Data.

An Interpretable Machine Learning Framework for Rare Disease: A Case Study to Stratify Infection Risk in Pediatric Leukemia

Background: Datasets on rare diseases, like pediatric acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), have small sample sizes that hinder machine learning (ML). The objective was to develop an interpretable ML framework to elucidate actionable insights from small tabular rare disease datasets. Methods: The comprehensive framework employed optimized data imputation and sampling, supervised and unsupervised learning, and literature-based discovery (LBD). The framework was deployed to assess treatment-related infection in pediatric AML and ALL. Results: An interpretable decision tree classified the risk of infection as either "high risk" or "low risk" in pediatric ALL (n = 580) and AML (n = 132) with accuracy of ∼79%. Interpretable regression models predicted the discrete number of developed infections with a mean absolute error (MAE) of 2.26 for bacterial infections and an MAE of 1.29 for viral infections. Features that best explained the development of infection were the chemotherapy regimen, cancer cells in the central nervous system at initial diagnosis, chemotherapy course, leukemia type, Down syndrome, race, and National Cancer Institute risk classification. Finally, SemNet 2.0, an open-source LBD software that links relationships from 33+ million PubMed articles, identified additional features for the prediction of infection, like glucose, iron, neutropenia-reducing growth factors, and systemic lupus erythematosus (SLE). Conclusions: The developed ML framework enabled state-of-the-art, interpretable predictions using rare disease tabular datasets. ML model performance baselines were successfully produced to predict infection in pediatric AML and ALL.

A Systematic Review of Cognition in Cervical Dystonia

Growing evidence points to a spectrum of non-motor symptoms, including cognitive difficulties that have a greater impact on functional outcomes and quality of life than motor symptoms in cervical dystonia (CD). Some cognitive impairments have been reported; however, findings are inconsistent, and described across mixed groups of dystonia. The current review aimed to examine the evidence for cognitive impairments in CD. MEDLINE, EMBASE, PsychINFO and Web of Science databases were searched. Studies were included if they met the following criteria (i) cross-sectional or longitudinal studies of adults with CD, (ii) where the results of standardised measures of cognitive or neuropsychological function in any form were assessed and reported, (iii) results compared to a control group or normative data, and (iv) were published in English. Results are presented in a narrative synthesis. Twenty studies were included. Subtle difficulties with general intellectual functioning, processing speed, verbal memory, visual memory, visuospatial function, executive function, and social cognition were identified while language, and attention and working memory appear to be relatively spared. Several methodological limitations were identified that should be considered when interpreting the evidence to describe a specific profile of cognitive impairment in CD. Clinical and research implications are discussed.

Rare disease research workflow using multilayer networks elucidates the molecular determinants of severity in Congenital Myasthenic Syndromes

Exploring the molecular basis of disease severity in rare disease scenarios is a challenging task provided the limitations on data availability. Causative genes have been described for Congenital Myasthenic Syndromes (CMS), a group of diverse minority neuromuscular junction (NMJ) disorders; yet a molecular explanation for the phenotypic severity differences remains unclear. Here, we present a workflow to explore the functional relationships between CMS causal genes and altered genes from each patient, based on multilayer network community detection analysis of complementary biomedical information provided by relevant data sources, namely protein-protein interactions, pathways and metabolomics. Our results show that CMS severity can be ascribed to the personalized impairment of extracellular matrix components and postsynaptic modulators of acetylcholine receptor (AChR) clustering. This work showcases how coupling multilayer network analysis with personalized -omics information provides molecular explanations to the varying severity of rare diseases; paving the way for sorting out similar cases in other rare diseases.

Clinical practice guidelines for the diagnosis and management of Duchenne muscular dystrophy: a scoping review

Introduction

Our objective was to identify recent CPGs for the diagnosis and management of DMD and summarize their characteristics and reliability.

Methods

We conducted a scoping review of CPGs using MEDLINE, the Turning Research Into Practice (TRIP) database, Google Scholar, guidelines created by organizations, and other repositories to identify CPGs published in the last 5 years. Our protocol was drafted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses for scoping reviews. To assess the reliability of the CPGs, we used all the domains included in the Appraisal of Guidelines Research and Evaluation II.

Results

We selected three CPGs published or updated between 2015 and 2020. All the guidelines showed good or adequate methodological rigor but presented pitfalls in stakeholder involvement and applicability domains. Recommendations were coherent across CPGs on steroid treatment, except for minor differences in dosing regimens. However, the recommendations were different for new drugs.

Discussion

There is a need for current and reliable CPGs that develop broad topics on the management of DMD and consider the challenges of developing recommendations for RDs.

Body Composition Evaluation and Clinical Markers of Cardiometabolic Risk in Patients with Phenylketonuria

Cardiovascular diseases are the main cause of mortality worldwide. Patients with phenylketonuria (PKU) may be at increased cardiovascular risk. This review provides an overview of clinical and metabolic cardiovascular risk factors, explores the connections between body composition (including fat mass and ectopic fat) and cardiovascular risk, and examines various methods for evaluating body composition. It particularly focuses on nutritional ultrasound, given its emerging availability and practical utility in clinical settings. Possible causes of increased cardiometabolic risk in PKU are also explored, including an increased intake of carbohydrates, chronic exposure to amino acids, and characteristics of microbiota. It is important to evaluate cardiovascular risk factors and body composition in patients with PKU. We suggest systematic monitoring of body composition to develop nutritional management and hydration strategies to optimize performance within the limits of nutritional therapy.

Precision medicine in monogenic inflammatory bowel disease: proposed mIBD REPORT standards

Owing to advances in genomics that enable differentiation of molecular aetiologies, patients with monogenic inflammatory bowel disease (mIBD) potentially have access to genotype-guided precision medicine. In this Expert Recommendation, we review the therapeutic research landscape of mIBD, the reported response to therapies, the medication-related risks and systematic bias in reporting. The mIBD field is characterized by the absence of randomized controlled trials and is dominated by retrospective observational data based on case series and case reports. More than 25 off-label therapeutics (including small-molecule inhibitors and biologics) as well as cellular therapies (including haematopoietic stem cell transplantation and gene therapy) have been reported. Heterogeneous reporting of outcomes impedes the generation of robust therapeutic evidence as the basis for clinical decision making in mIBD. We discuss therapeutic goals in mIBD and recommend standardized reporting (mIBD REPORT (monogenic Inflammatory Bowel Disease Report Extended Phenotype and Outcome of Treatments) standards) to stratify patients according to a genetic diagnosis and phenotype, to assess treatment effects and to record safety signals. Implementation of these pragmatic standards should help clinicians to assess the therapy responses of individual patients in clinical practice and improve comparability between observational retrospective studies and controlled prospective trials, supporting future meta-analysis.

Using PRPP-Assessment for measuring change in everyday activities by home-based videos: An exploratory case series study in children with multiple disabilities

BACKGROUND

Currently, paediatric health care aims to use a child-centred tailor-made approach. In order to design tailored occupational therapy, the implementation of personalised occupation-based measurements that guide and evaluate goal setting and are responsive to change is necessary.

PURPOSE

Primarily, this study explored the potential of the Perceive, Recall, Plan, and Perform (PRPP) assessment to measure the change in the performance of children with multiple disabilities. As a secondary evaluation, the feasibility of the PRPP-Intervention in a home-based program to enable activities was described. The overall aim is to show the potential of the PRPP-Assessment as an outcome measure to use as a base for designing tailor-made person-centred care.

METHODS

An exploratory longitudinal multiple case series mixed-methods design was used. The PRPP-Assessment, scored by multiple raters, was conducted based on parent-provided videos. The assessed activities were chosen by the child and/or parents. Responsiveness was evaluated by hypotheses formulated a priori and by comparing measured change with change on concurrent measures: Goal Attainment Scaling (GAS) and Canadian Occupational Performance Measure (COPM). Over a 6-week period, children and their parents (or caregivers) participated in an online home-based video coaching program where parents were coached in the implementation of the training, based on the PRPP-Intervention, by paediatric occupational therapists on a weekly basis. The feasibility of the intervention was explored using semi-structured interviews with children, parents, and the treating occupational therapists and was analysed by directed content analysis.

RESULTS

Three out of 17 eligible children agreed to participate and completed post-intervention measurement, of which two completed the intervention. Quantitative results showed that eight out of nine activities improved on the PRPP-Assessment and the COPM, and nine improved on the GAS. In total, 13 out of 15 hypotheses for responsiveness were accepted. Participants experienced the intervention as successful and acceptable. Facilitators and concerns over demand, implementation, practicality, integration, and adaptation were shared.

CONCLUSION

The PRPP-Assessment showed the potential to measure change in a heterogeneous group of children. The results indicated a positive tendency for the intervention and also provide directions for further development.

Improving visual outcomes in patients with rare paediatric eye diseases

Introduction

Rare paediatric eye diseases (RPEDs) threaten both vision and life. Recently, rare diseases were recognised as a global public health agenda, with children specified as a priority in the World Health Organization's VISION 2020 against avoidable visual loss.

Method

We conducted a review through a query of online databases (PubMed, Embase and Cochrane Library). Articles related to RPEDs were selected based on relevance by 2 authors, with any disagreements adjudicated by the third author.

Results

We synthesise the current state of knowledge regarding RPEDs, barriers to their care, and recommendations for the future. RPEDs often result in significant visual loss, profoundly impacting the way children comprehend and participate in the world. These diseases may also reduce life expectancy and even be life-threatening. Barriers to the care of RPEDs include an unclear definition of "rare diseases", missed or delayed diagnosis, inadequate knowledge and expertise in management, and challenging research environments.

Conclusion

Our findings provide an update on the diagnosis and management of RPEDs, which is of relevance to ophthalmologists, paediatricians, healthcare policymakers and social workers. We propose supportive policies and adequate resource allocation to these diseases, comprehensive and patient-centred care, alongside improved education and training, enhanced research capabilities and continued collaboration across institutions.

Pharmacovigilance for rare diseases: a bibliometrics and knowledge-map analysis based on web of science

OBJECTIVES

The aims of this paper is to search and explore publications in the field of pharmacovigilance for rare diseases and to visualize general information, research hotspots, frontiers and future trends in the field using the bibliometric tool CiteSpace to provide evidence-based evidence for scholars.

METHODS

We searched the Web of Science Core Collection (WoSCC) for studies related to pharmacovigilance for rare diseases, spanning January 1, 1997-October 25, 2022. CiteSpace software was utilized to discuss countries/regions, institutions, authors, journals, and keywords.

RESULTS

After screening, a total of 599 valid publications were included in this study, with a significant upward trend in the number of publications. These studies were from 68 countries/regions with the United States and the United Kingdom making the largest contributions to the field. 4,806 research scholars from 493 institutions conducted studies on pharmacovigilance for rare diseases. Harvard University and University of California were the top two productive institutions in the research field. He Dian of the Affiliated Hospital of Guizhou Medical University and Peter G.M. Mol of the University of Groningen, The Netherlands, were the two most prolific researchers. The Cochrane Database of Systematic Reviews and the New England Journal of Medicine were the journals with the highest number of articles and co-citation frequency respectively. Clinical trial, therapy and adverse event were the top three most cited keywords.

CONCLUSIONS

Based on keywords co-occurrence analysis, four research topics were identified: orphan drug clinical trials, postmarketing ADR surveillance for orphan drugs, rare diseases and orphan drug management, and diagnosis and treatment of rare diseases. Immune-related adverse reactions and benefit-risk assessment of enzyme replacement therapy were at the forefront of research in this field. Treatment outcomes, early diagnosis and natural history studies of rare diseases may become hotspots for future research.

Designs used in published therapeutic studies of rare superficial vascular anomalies: a systematic literature search

BACKGROUND

Rare superficial vascular anomalies represent a wide range of diseases. Their management is difficult given the broad spectrum and the lack of clinical trials assessing treatment efficacy. A randomized clinical trial of vascular anomalies is difficult because of the rarity of the diseases and is enhanced by the population of interest often being children. Therefore, suitable designs are needed. We conducted a methodological systematic literature search to identify designs implemented for investigating the treatment of rare superficial vascular anomalies.

METHODS

We conducted a literature search on January 25, 2021, of the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, ClinicalTrials.gov and European Union Clinical Trials Register databases. This systematic methodological literature search was registered at the Prospective Register of Systematic Reviews (PROSPERO: CRD42021232449). Randomized and non-randomized studies were included if they met the following criteria: were prospective studies of rare superficial vascular anomaly therapies, dealt with humans (adults and children) and were published in English from 2000. We excluded case reports/case series reporting fewer than 10 patients, reviews, retrospective studies, animal studies, studies of systemic or common vascular anomalies and non-therapeutic studies. We did not assess risk of bias in the included studies because our review was a methodological one focused on the design used. The review provided a descriptive analysis of relevant features of eligible research studies.

RESULTS

From 2046 articles identified, we included 97 studies (62 reports and 35 ongoing studies): 25 randomized controlled studies, 7 non-randomized comparative studies, 64 prospective cohorts and 1 case series. Among the 32 comparative studies included, 21 used a parallel-group design. The 11 other studies used different designs such as cross-over, randomized placebo phase, delayed-start, within-person, or challenge-dechallenge-rechallenge or used a historical control group or an observational run-in period.

CONCLUSIONS

Our systematic literature search highlights the lack of randomized control trials in superficial vascular anomalies due to the rarity of patients and their heterogeneity. New designs are emerging and can overcome the limitations of testing treatments in parallel groups.

Neutral theory: applicability and neutrality of clinical study endpoints where a disease-specific instrument is available

BACKGROUND

There is a pressing need to improve the accuracy of rare disease clinical study endpoints. Neutral theory, first described here, can be used to assess the accuracy of endpoints and improve their selection in rare disease clinical studies, reducing the risk of patient misclassification.

METHODS

Neutral theory was used to assess the accuracy of rare disease clinical study endpoints and the resulting probability of false positive and false negative classifications at different disease prevalence rates. Search strings were extracted from the Orphanet Register of Rare Diseases using a proprietary algorithm to conduct a systematic review of studies published until January 2021. Overall, 11 rare diseases with one disease-specific disease severity scale (133 studies) and 12 rare diseases with more than one disease-specific disease severity scale (483 studies) were included. All indicators from clinical studies were extracted, and Neutral theory was used to calculate their match to disease-specific disease severity scales, which were used as surrogates for the disease phenotype. For those with more than one disease-severity scale, endpoints were compared with the first disease-specific disease severity scale and a composite of all later scales. A Neutrality score of > 1.50 was considered acceptable.

RESULTS

Around half the clinical studies for half the rare diseases with one disease-specific disease severity score (palmoplantar psoriasis, achalasia, systemic lupus erythematosus, systemic sclerosis and Fournier's gangrene) met the threshold for an acceptable match to the disease phenotype, one rare disease (Guillain-Barré syndrome) had one study with an acceptable match, and four diseases (Behcet's syndrome, Creutzfeldt-Jakob disease, atypical hemolytic uremic syndrome and Prader-Willi syndrome) had no studies. Clinical study endpoints in almost half the rare diseases with more than one disease-specific DSS (acromegaly, amyotrophic lateral sclerosis, cystic fibrosis, Fabry disease and juvenile rheumatoid arthritis) were a better match to the composite, while endpoints in the remaining rare diseases (Charcot Marie Tooth disease, Gaucher disease Type I, Huntington's disease, Sjogren's syndrome and Tourette syndrome) were a worse match. Misclassifications varied with increasing disease prevalence.

CONCLUSIONS

Neutral theory confirmed that disease-severity measurement needs improvement in rare disease clinical studies, especially for some diseases, and suggested that the potential for accuracy increases as the body of knowledge on a disease increases. Using Neutral theory to benchmark disease-severity measurement in rare disease clinical studies may reduce the risk of misclassification, ensuring that recruitment and treatment effect assessment optimise medicine adoption and benefit patients.

Health-related quality of life (HRQoL) and psychological impact of the COVID-19 pandemic on patients with myasthenia gravis

The aim of this study was to compare the effects of the pandemic on health-related quality of life (HRQoL), anxious-depressive symptoms, feelings of loneliness, and fear of COVID-19 between people with myasthenia gravis (MG) and healthy controls. We also wanted to know in which group the variable fear of COVID-19 interfered the most with the results. This cross-sectional study involved 60 people with MG and 60 healthy controls. Participants using an online platform completed a sociodemographic questionnaire, the Short Form-36 Health Survey (SF-36), the Hospital Anxiety and Depression Scale (HADS), the revised UCLA Loneliness Scale and the Fear of COVID19 Scale (FCV- 19S). The MG group reported worse levels in HRQoL indicators (p = 0.043- <.001), more severe anxiety-depressive symptoms (p = 0.002), and greater fear of COVID-19 (p < 0.001), but there were no differences in feelings of loneliness (p = 0.002). Furthermore, after controlling for the effect of the fear of COVID-19 variable, the differences remained for physical health indicators, but not for the most of psychosocial indicators (Social Functioning p = 0.102, η²_p = 0.023; Role Emotional p = 0.250, η²_p = 0.011; and HADS Total p = 0.161, η²_p = 0.017). The harmful effect of the COVID-19 pandemic was greater in the MG group, and the perceived fear of COVID-19 had also a greater impact among this group, which has increased its negative effect on their psychosocial health.

Biosimilars in rare diseases: a focus on paroxysmal nocturnal hemoglobinuria

Biologics, a class of medicines grown in and purified from genetically engineered cell cultures, have transformed the management of many cancers and rare diseases, such as paroxysmal nocturnal hemoglobinuria. As prescription drug spending has increased and exclusivity periods have expired, manufacturers have developed biosimilars-biologics that may be more affordable and highly similar to a licensed biological therapeutic, with no clinically meaningful differences in terms of safety or efficacy. With biosimilars gaining regulatory approval around the globe and broadening patient access to biologics, this review aims to help rare disease healthcare providers familiarize themselves with biosimilars, understand their development and regulatory approval process, and address practical considerations that may facilitate their use.

Randomized controlled trial data for successful new drug application for rare diseases in the United States

BACKGROUND

Randomized controlled trial (RCT) data have important implications in drug development. However, the feasibility and cost of conducting RCTs lower the motivation for drug development, especially for rare diseases. We investigated the potential factors associated with the need for RCTs in the clinical data package for new drug applications for rare diseases in the United States (US). This study focused on 233 drugs with orphan drug designations approved in the US between April 2001 and March 2021. Univariable and multivariable logistic regression analyses were conducted to investigate the association between the presence or absence of RCTs in the clinical data package for new drug applications.

RESULTS

Multivariable logistic regression analysis showed that the severity of the disease outcome (odds ratio [OR] 5.63, 95% confidence interval [CI] 2.64-12.00), type of drug usage (odds ratio [OR] 2.95, 95% confidence interval [CI] 1.80-18.57), and type of primary endpoint (OR 5.57, 95% CI 2.57-12.06) were associated with the presence or absence of RCTs.

CONCLUSIONS

Our results indicated that the presence or absence of RCT data in the clinical data package for successful new drug application in the US was associated with three factors: severity of disease outcome, type of drug usage, and type of primary endpoint. These results highlight the importance of selecting target diseases and potential efficacy variables to optimize orphan drug development.

Approaches to the Assessment of Clinical Benefit of Treatments for Conditions That Have Heterogeneous Symptoms and Impacts: Potential Applications in Rare Disease

OBJECTIVES

Evaluating the clinical benefit of interventions for conditions with heterogeneous symptom and impact presentations is challenging. The same condition can present differently across and within individuals over time. This occurs frequently in rare diseases. The purpose of this review was to identify (1) assessment approaches used in clinical trials to address heterogeneous manifestations that could be relevant in rare disease research and (2) US Food and Drug Administration (FDA)-approved labeling claims that used these approaches.

METHODS

A targeted literature review was conducted examining peer-reviewed publications and FDA-approved labeling claims from January 2002 to July 2020, focusing on claims incorporating clinical outcome assessments. Approaches were then assessed for their potential application in rare diseases.

RESULTS

A total of 6 assessment approaches were identified: composite or other multicomponent endpoints, multidomain responder index, most bothersome symptom (MBS), goal attainment scaling, sliding dichotomy, and adequate relief. A total of 59 FDA-approved labeling claims associated with these approaches were identified: composite or other multicomponent endpoints (n=49), MBS (n=9), and adequate relief (n=1). A total of 10 FDA-approved labeling claims, all using multicomponent endpoints, were identified for rare diseases.

CONCLUSIONS

Multicomponent, MBS, and adequate relief have been included in FDA-approved labeling claims. Multicomponent endpoints, including composite endpoints, were the most frequent way to address heterogeneous manifestations of both common and rare diseases. MBS may be acceptable to regulators, whereas multidomain responder index is unlikely to be. The goal attainment scaling and adequate relief approaches may have potential utility in rare disease trials, assuming the theoretical and statistical challenges inherent in each approach are managed.

Transanal irrigation is a better choice for bowel dysfunction in adults with Spina bifida: A randomised controlled trial

AIM

To compare transanal irrigation with conservative bowel management for the treatment of bowel dysfunction in Spina bifida (SB) patients.

METHODS

Patients with SB and bowel dysfunction were randomly assigned to receive either transanal irrigation or conservative bowel management. The effectiveness of the treatment was defined as a decrease of 4 points in the neurogenic bowel dysfunction (NBD) score at week 10. Data on incontinence (Cleveland scores; Jorge-Wexner [JW]) and constipation (Knowles-Eccersley-Scott Symptom Constipation Score [KESS]) were recorded at 10 and 24 weeks after inclusion. Data were analysed on an intention-to-treat basis.

RESULTS

A total of 34 patients were randomised: 16 patients to conservative bowel management and 18 patients to transanal irrigation. A total of 19/31 (61%) patients improved at week 10, 13 (76%) in the transanal irrigation group versus six (43%) in the conservative group (p = 0.056). In the irrigation group, the decrease in NBD score was -6.9 (-9.9 to -4.02) versus -1.9 (-6.5 to -2.8) in the conservative group (p = 0.049 in univariate and p = 0.004 in multivariate analysis). The NBD, Cleveland (JW and KESS) and Rosenberg scores were significantly lower in the transanal irrigation group than in the conservative bowel management group at week 10.

CONCLUSIONS

This prospective, randomised, controlled, multicentre study in adult patients with SB suggests that transanal irrigation may be more effective than conservative bowel management.

Rare diseases and space health: optimizing synergies from scientific questions to care

Knowledge transfer among research disciplines can lead to substantial research progress. At first glance, astronaut health and rare diseases may be seen as having little common ground for such an exchange. However, deleterious health conditions linked to human space exploration may well be considered as a narrow sub-category of rare diseases. Here, we compare and contrast research and healthcare in the contexts of rare diseases and space health and identify common barriers and avenues of improvement. The prevalent genetic basis of most rare disorders contrasts sharply with the occupational considerations required to sustain human health in space. Nevertheless small sample sizes and large knowledge gaps in natural history are examples of the parallel challenges for research and clinical care in the context of both rare diseases and space health. The two areas also face the simultaneous challenges of evidence scarcity and the pressure to deliver therapeutic solutions, mandating expeditious translation of research knowledge into clinical care. Sharing best practices between these fields, including increasing participant involvement in all stages of research and ethical sharing of standardized data, has the potential to contribute to humankind's efforts to explore ever further into space while caring for people on Earth in a more inclusive fashion.

Sharing is caring: a call for a new era of rare disease research and development

Scientific advances in the understanding of the genetics and mechanisms of many rare diseases with previously unknown etiologies are inspiring optimism in the patient, clinical, and research communities and there is hope that disease-specific treatments are on the way. However, the rare disease community has reached a critical point in which its increasingly fragmented structure and operating models are threatening its ability to harness the full potential of advancing genomic and computational technologies. Changes are therefore needed to overcome these issues plaguing many rare diseases while also supporting economically viable therapy development. In "Data silos are undermining drug development and failing rare disease patients (Orphanet Journal of Rare Disease, Apr 2021)," we outlined many of the broad issues underpinning the increasingly fragmented and siloed nature of the rare disease space, as well as how the issues encountered by this community are representative of biomedical research more generally. Here, we propose several initiatives for key stakeholders - including regulators, private and public foundations, and research institutions - to reorient the rare disease ecosystem and its incentives in a way that we believe would cultivate and accelerate innovation. Specifically, we propose supporting non-proprietary patient registries, greater data standardization, global regulatory harmonization, and new business models that encourage data sharing and research collaboration as the default mode. Leadership needs to be integrated across sectors to drive meaningful change between patients, industry, sponsors, and academic medical centers. To transform the research and development landscape and unlock its vast healthcare, economic, and scientific potential for rare disease patients, a new model is ultimately the goal for all.

Developing guidelines for ultrarare rheumatic disorders: a bumpy ride

Clinical practice guidelines are useful tools for both patients and physicians. Several standardised operating procedures are in existence to describe tasks step by step to develop guidelines/recommendations. The end product consists of data synthesis from the systematic literature search and patient/physician's inputs. For the prevalent diseases, the process for developing guidelines is straightforward; it is based on physicians'/patients' experiences and abundance of the literature. When it comes to the realm of ultrarare diseases, there are few physicians who are familiar with a disease, and there is a scarcity of literature. In this viewpoint, we describe challenges from the methodological perspectives that occurred during the process of developing recommendations for autoinflammatory disorders with the goal of finding solutions that facilitate the development of guidelines for ultrarare diseases in the future.

Randomized Controlled Trial Data for New Drug Application for Rare Diseases in Japan

BACKGROUND

High-quality evidence is often not obtained in the clinical trials of rare diseases because these trials tend to be smaller in size and non-controlled. We investigated the potential factors associated with the need for randomized controlled trials (RCTs) in the clinical data package for new drug applications for rare diseases in Japan.

METHODS

This study focused on 130 drugs with orphan drug designation approved in Japan between April 2004 and March 2020.

RESULTS

Multivariable regression analysis showed that the prevalence (odds ratio [OR] 3.21, 95% confidence interval [CI] 1.18-8.6) and the type of primary endpoint (OR 6.66, 95% CI 2.41-18.37) were associated with the need for RCTs in the clinical data package in Japan.

CONCLUSIONS

Our findings highlight the importance of adequate understanding of the target disease in new drug development for rare diseases.

Estimating the Prevalence of Rare Diseases: Long-Chain Fatty Acid Oxidation Disorders as an Illustrative Example

Introduction

Determining the epidemiology of disease is critical for multiple reasons, including to perform risk assessment, compare disease rates in varying populations, support diagnostic decisions, evaluate health care needs and disease burden, and determine the economic benefit of treatment. However, establishing epidemiological measures for rare diseases can be difficult owing to small patient populations, variable diagnostic techniques, and potential disease and diagnostic heterogeneity. To determine the epidemiology of rare diseases, investigators often develop estimation models to account for missing or unobtainable data, and to ensure that their findings are representative of their desired patient population.

Methods

A modeling methodology to estimate the prevalence of rare diseases in one such population—patients with long-chain fatty acid oxidation disorders (LC-FAOD)—as an illustrative example of its applicability.

Results

The proposed model begins with reliable source data from newborn screening reports and applies to them key modifiers. These modifiers include changes in population growth over time and variable standardization rates of LC-FAOD screening that lead to (1) a confirmed diagnosis and (2) improvements in standards of care and survival estimates relative to the general population. The model also makes necessary assumptions to allow the broad applicability of the estimation of LC-FAOD prevalence, including rates of diagnosed versus undiagnosed patients in the USA over time.

Conclusions

Although each rare disease is unique, the approach described here and demonstrated in the estimation of LC-FAOD prevalence provides the necessary tools to calculate key epidemiological estimates useful in performing risk assessment analyses; comparing disease rates between different subgroups of people; supporting diagnostic decisions; planning health care needs; comparing disease burden, including cost; and determining the economic benefit of treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02186-2.

Necessity of Prophylactic Extrapleural Chest Tube During Primary Surgical Repair of Esophageal Atresia: A Systematic Review and Meta-Analysis

Background

Esophageal atresia is corrected surgically by anastomosing and recreating esophageal continuity. To allow the removal of excess fluid and air from the anastomosis, a prophylactic and temporary intraoperative chest tube (IOCT) has traditionally been placed in this area during surgery. However, whether the potential benefits of this prophylactic IOCT overweigh the potential harms is unclear.

Objective

To assess the benefits and harms of using a prophylactic IOCT during primary surgical repair of esophageal atresia.

Data Sources

We conducted a systematic review with a meta-analysis. We searched Cochrane Central Register of Controlled Trials (2021, Issue 12), MEDLINE Ovid, Embase Ovid, CINAHL, and Science Citation Index Expanded and Conference Proceedings Citation Index-(Web of Science). Search was performed from inception until December 3rd, 2021.

Study Selection

Randomized clinical trials (RCT) assessing the effect of a prophylactic IOCT during primary surgical repair of esophageal atresia and observational studies identified during our searches for RCT.

Data Extraction and Synthesis

Two independent reviewers screened studies and performed data extraction. The certainty of the evidence was assessed by GRADE and ROBINS-I.

PROSPERO Registration

A protocol for this review has been registered on PROSPERO (CRD42021257834).

Results

We included three RCTs randomizing 162 neonates, all at overall "some risk of bias." The studies compared the placement of an IOCT vs. none. The meta-analysis did not identify any significant effect of profylacitic IOCT, as confidence intervals were compatible with no effect, but the analyses suggests that the placement of an IOCT might lead to an increase in all-cause mortality (RR 1.66, 95% CI 0.76-3.65; three trials), serious adverse events (RR 1.08, 95% CI 0.58-2.00; three trials), intervention-requiring pneumothorax (RR 1.65, 95% CI 0.28-9.50; two trials), and anastomosis leakage (RR 1.66, 95% CI 0.63-4.40). None of our included studies assessed esophageal stricture or pain. Certainty of evidence was very low for all outcomes.

Conclusions

Evidence from RCTs does not support the routine use of a prophylactic IOCT during primary surgical repair of esophageal atresia.

Dental Implants in People with Osteogenesis Imperfecta: A Systematic Review

The aim of this systematic review was to answer the question of whether patients with osteogenesis imperfecta can be prosthetically rehabilitated with dental implants. A protocol was prospectively registered in PROSPERO (CRD42021286368). The inclusion criteria were the presence of osteogenesis imperfecta and the use of implants for prosthetic restorations. Cases in which the inclusion criteria were not met were excluded. PubMed, Web of Science, and Scopus were last searched on 22 August 2021. Quality assessment was performed using the Methodological Quality and Synthesis of Case Series and Case Reports tool. The primary outcome was implant survival. Supporting data were analyzed descriptively. Twelve studies were included. Twenty-three patients received a total number of 116 implants, with 5.0 (±3.8) implants placed per patient. The implant survival rate was 94.0% with a mean follow-up of 59.1 months (±36.1). A limitation of this review was the relatively short follow-up time in some of the included studies; therefore, the survival rate may be overestimated. Nevertheless, the available data showed the loss of only seven implants, with two implants lost due to implant fractures not attributable to the patient. With the limitations of this review and based on the available data, dental implants have a high survival rate in patients with osteogenesis imperfecta. Therefore, dental implants may be a viable treatment option for replacing missing teeth. This research was not funded by external resources.

A survey of registered pharmacological clinical trials on rare neurological diseases in children in 2010-2020

OBJECTIVE

To clarify the current state of methodology of clinical trials for rare neurological diseases in children, and to provide a basis for the further optimization of the trial design.

METHODS

Data of clinical trials for the rare neurological diseases with childhood onset (searched through https://rarediseases.info.nih.gov/diseases and www.Orpha.net) registered on the Clinicaltrils.gov from January 2010 to June 2020 was collected. Analysis on the methodology of the clinical trials were performed, focusing on initiator of the studies, multi or single research center, study design, sample size, and the endpoint using in the trial.

RESULTS

A total of 162 clinical trials were included, covering only 7.3% (61/835) of rare neurological diseases in children. 101 (62.3%) were initiated by pharmaceutical companies, and 61 (37.7%) by investigators. Most (95.4%) of global multicenter studies were initiated by pharmaceutical companies, whereas most (70.0%) of single-center studies were initiated by investigators (χ ²= 61.635, P < 0.001). Of the 162 trials, 74 (45.7%) were open-label single-arm trials, 68 (42.0%) were randomized double-blind parallel controlled trials (RCT), 12 (7.4%) were randomized crossover trials. Most of RCTs (73.5%) and 54.1% of open-label single-arm trials were initiated by pharmaceutical companies. The proportion of RCTs in clinical trials for diseases with a prevalence of ≥1/10,000 (62.5%) was higher than that in diseases with prevalence ≤1/1,000,000 (12.0%) or 1/1,000,000~1/10,000 (43.1%) (χ ²= 14.790, P = 0.001). The median expected sample size of the studies was 34 (4-500). 132 (132/162, 81.5%) studies enrolled fewer than 100 cases. Diseases with a prevalence of ≥1/10,000 had significantly larger sample sizes than other prevalence classes (P < 0.001, P = 0.003).

CONCLUSIONS

There were few clinical trials targeting on treatment of rare neurological diseases in children. Trials on rare diseases used fewer participants, and high-quality randomized controlled trials were less common. It is necessary to conduct global multicenter recruitment and choose optimal study designs to improve the level of evidence in clinical trials on rare diseases.

Elosulfase alfa in the treatment of mucopolysaccharidosis type IVA: insights from the first managed access agreement

Managed access agreements provide a crucial mechanism whereby real-world data can be collected systematically to reduce uncertainty around available clinical and economic data, whilst providing the opportunity to identify patient sub-populations who are most likely to benefit from a new treatment. This manuscript aims to share learnings from the first managed access agreement, which was initiated following positive conditional approval in 2015 from the National Institute for Health and Care Excellence (NICE) for elosulfase alfa, an enzyme replacement therapy for the treatment of mucopolysaccharidosis type IVA (MPS IVA). This managed access agreement enabled the collection of comprehensive real-world data for patients with MPS IVA, with results demonstrating that patients starting elosulfase alfa treatment showed gains similar to those seen in the pivotal trial for outcomes including endurance, respiratory and cardiac function, pain, quality of life measures and urinary keratan sulfate levels. In addition, former trial patients continued to see benefits in both clinical assessments and quality of life/activities of daily living nine years after beginning treatment. Key strengths of the process included recruitment of a high proportion of MPS IVA patients treated in England (72/89 known eligible patients) with a wide range of ages (2-58 years). Participation of a patient organisation (the MPS society) ensured that the patient voice was present throughout the process, whilst a contract research organisation (Rare Disease Research Partners) ensured that patients were represented when interpreting agreement criteria and during patient assessment meetings. Longer-term follow-up will be required for several MPS IVA outcomes (e.g. skeletal measures) to further reduce uncertainty, and continued follow-up of patients who had stopped treatment was found to be challenging. The burden associated with this managed access agreement was found to be high for patients, physicians, patient organisations, NHS England and the manufacturer, therefore costs and benefits of future agreements should be considered carefully before initiation. Through evaluation of the strengths and limitations of this process, it is hoped that learnings from this managed access agreement can be used to inform future agreements.

Finding commonalities in rare diseases through the undiagnosed diseases network

Objective

When studying any specific rare disease, heterogeneity and scarcity of affected individuals has historically hindered investigators from discerning on what to focus to understand and diagnose a disease. New nongenomic methodologies must be developed that identify similarities in seemingly dissimilar conditions.

Materials and Methods

This observational study analyzes 1042 patients from the Undiagnosed Diseases Network (2015-2019), a multicenter, nationwide research study using phenotypic data annotated by specialized staff using Human Phenotype Ontology terms. We used Louvain community detection to cluster patients linked by Jaccard pairwise similarity and 2 support vector classifier to assign new cases. We further validated the clusters’ most representative comorbidities using a national claims database (67 million patients).

Results

Patients were divided into 2 groups: those with symptom onset before 18 years of age (n = 810) and at 18 years of age or older (n = 232) (average symptom onset age: 10 [interquartile range, 0-14] years). For 810 pediatric patients, we identified 4 statistically significant clusters. Two clusters were characterized by growth disorders, and developmental delay enriched for hypotonia presented a higher likelihood of diagnosis. Support vector classifier showed 0.89 balanced accuracy (0.83 for Human Phenotype Ontology terms only) on test data.

Discussions

To set the framework for future discovery, we chose as our endpoint the successful grouping of patients by phenotypic similarity and provide a classification tool to assign new patients to those clusters.

Conclusion

This study shows that despite the scarcity and heterogeneity of patients, we can still find commonalities that can potentially be harnessed to uncover new insights and targets for therapy.

National registry for amyotrophic lateral sclerosis: a systematic review for structuring population registries of motor neuron diseases

BACKGROUND

This article comprises a systematic review of the literature that aims at researching and analyzing the frequently applied guidelines for structuring national databases of epidemiological surveillance for motor neuron diseases, especially Amyotrophic Lateral Sclerosis (ALS).

METHODS

We searched for articles published from January 2015 to September 2019 on online databases as PubMed - U.S. National Institutes of Health's National Library of Medicine, Scopus, Science Direct, and Springer. Subsequently, we analyzed studies that considered risk factors, demographic data, and other strategic data for directing techno-scientific research, calibrating public health policies, and supporting decision-making by managers through a systemic panorama of ALS.

RESULTS

2850 studies were identified. 2400 were discarded for not satisfying the inclusion criteria, and 435 being duplicated or published in books or conferences. Hence, 15 articles were elected. By applying quality criteria, we then selected six studies to compose this review. Such researches featured registries from the American (3), European (2), and Oceania (1) continent. All the studies specified the methods for data capture and the patients' recruitment process for the registers.

DISCUSSIONS

From the analysis of the selected papers and reported models, it is noticeable that most studies focused on the prospect of obtaining data to characterize research on epidemiological studies. Demographic data (ID01) are present in all the registries, representing the main collected data category. Furthermore, the general health history (ID02) is present in 50% of the registries analyzed. Characteristics such as access control, confidentiality and data curation. We observed that 50% of the registries comprise a patient-focused web-based self-report system.

CONCLUSION

The development of robust, interoperable, and secure electronic registries that generate value for research and patients presents itself as a solution and a challenge. This systematic review demonstrated the success of a population register requires actions with well-defined development methods, as well as the involvement of various actors of civil society.

Ethical Issues in Care and Treatment of Neuronal Ceroid Lipofuscinoses (NCL)-A Personal View

The management of Neuronal Ceroid Lipofuscinoses (NCL), a group of genetic neurodegenerative disorders mainly affecting brain and retinas, raises difficult questions for physicians and other professionals in research, pharmaceutical industry, and public health. Ethical problems in medicine cannot be solved by rational deliberation or by following formal rules. Two topics of ethical issues in the field of NCL are presented here. One group relates to the care of individual patients and centers on a life with dementia at a young age. Advanced care planning for the end of life and the use of life-prolonging measures require challenging assumptions in the best interest of a patient. A second group of questions relates to new treatments. Impressive novel putative causal therapies, such as enzyme replacement for CLN2 disease, may be only disease-modifying and carry the risk of changing a deadly disease of short duration into one with prolonged survival and poor quality of life. The wish for better therapeutic interventions in life-limiting diseases has to take such risks, but more experience is needed before definite conclusions can be drawn. The appropriateness of presymptomatic screening for a severe disease, e.g., must be carefully evaluated to avoid the disastrous experience made with the rash start of newborn screening for Krabbe disease. The ethical issues described and commented in the article reflect the personal experience of a pediatrician who has studied clinical and research questions in NCL for four decades. They should alert various professionals to the necessity of taking their own decisions in situations that are caused by rare progressive brain diseases of young persons, as typified by the NCL.

Electrical neuromodulation in bladder dysfunction: Mapping the state-of-the-art with bibliometric analysis of field and top 100 cited articles

AIMS

Electrical neuromodulation of bladder function has been extensively investigated in the literature. To date, there has been no characterization of the field, and there is a lack of bibliometric literature to guide future studies. We directed this scientometric analysis to characterize the distribution, characteristics and relationships of the field, with subanalysis of top 100 articles.

METHODS

The Web of Science Core Collection of the Thompson Reuters Web of Science was searched and analyzed to determine distributions and characteristics of clinical research investigating electrical neuromodulation in bladder dysfunction. Field citation and coauthorship networks were mapped, and recent citation bursts of the past decade are described. The top 100 cited articles were categorized, with level of evidence rating system applied.

RESULTS

A total of 872 articles published from 1949 until October 2020 were included in field analysis. Europe demonstrated the highest continental productivity within field (n = 539, 61.81%), and the United States the top nation (35.55% of field, 39.24% of top 100 articles). The Journal of Urology has historically published the most articles in the field (n = 150, 17.20%), and top 100 articles (n = 41, 40.20%). Top 100 articles reported studies of neuromodulation effects via sacral neuromodulation (n = 59); of non-neurological bladder dysfunction (n = 72); urinary incontinence (n = 92), frequency (n = 73) and urgency (n = 68) symptomology.

CONCLUSIONS

Analysis of electrical neuromodulation of bladder dysfunction literature reveals historical development, core research clusters and relationships, and an increase in publication activity over past decades.

Patient Recruitment Into a Multicenter Clinical Cohort Linking Electronic Health Records From 5 Health Systems: Cross-sectional Analysis

Background

There is growing interest in identifying and recruiting research participants from health systems using electronic health records (EHRs). However, few studies have described the practical aspects of the recruitment process or compared electronic recruitment methods to in-person recruitment, particularly across health systems.

Objective

The objective of this study was to describe the steps and efficiency of the recruitment process and participant characteristics by recruitment strategy.

Methods

EHR-based eligibility criteria included being an adult patient engaged in outpatient primary or bariatric surgery care at one of 5 health systems in the PaTH Clinical Research Network and having ≥2 weight measurements and 1 height measurement recorded in their EHR within the last 5 years. Recruitment strategies varied by site and included one or more of the following methods: (1) in-person recruitment by study staff from clinical sites, (2) US postal mail recruitment letters, (3) secure email, and (4) direct EHR recruitment through secure patient web portals. We used descriptive statistics to evaluate participant characteristics and proportion of patients recruited (ie, efficiency) by modality.

Results

The total number of eligible patients from the 5 health systems was 5,051,187. Of these, 40,048 (0.8%) were invited to enter an EHR-based cohort study and 1085 were enrolled. Recruitment efficiency was highest for in-person recruitment (33.5%), followed by electronic messaging (2.9%), including email (2.9%) and EHR patient portal messages (2.9%). Overall, 779 (65.7%) patients were enrolled through electronic messaging, which also showed greater rates of recruitment of Black patients compared with the other strategies.

Conclusions

We recruited a total of 1085 patients from primary care and bariatric surgery settings using 4 recruitment strategies. The recruitment efficiency was 2.9% for email and EHR patient portals, with the majority of participants recruited electronically. This study can inform the design of future research studies using EHR-based recruitment.

Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION): 10-Year Update

Purpose of Review

APS ACTION is an international research network created to design and conduct large-scale, multicenter research in persistently antiphospholipid antibody (aPL)–positive patients. Given the expanding research activities of the network in the last decade since its creation, the purpose of this article is to review the scientific contributions of APS ACTION as well as future directions.

Recent Findings

APS ACTION has achieved increased international collaboration with internal and external investigators for outcome, interventional, and mechanistic antiphospholipid syndrome (APS) studies. This has been linked to substantial progress in Core laboratory work, which has demonstrated that laboratories can achieve good agreement in performance of aPL assays by use of the same reagents, analyzer type, and protocols.

Summary

APS ACTION will continue to identify gaps in the existing aPL/APS literature, design mechanistic studies to elucidate underlying mechanisms, and conduct prospective, large-scale clinical studies, all for the ultimate goal of early diagnosis and improved management of aPL-positive patients.

COVID-PCD: a participatory research study on the impact of COVID-19 in people with primary ciliary dyskinesia

COVID-PCD is a participatory study initiated by people with primary ciliary dyskinesia (PCD) who have an essential vote in all stages of the research from the design of the study to the recruitment of participants, and interpretation and communication of the study results. COVID-PCD aims to collect epidemiological data in real-time from people with PCD throughout the pandemic to describe incidence of coronavirus disease 2019 (COVID-19), symptoms and course of disease; identify risk factors for prognosis; and assess experiences, wishes and needs. The study is advertised through patient support groups and participants register online on the study website (www.covid19pcd.ispm.ch). The study invites persons of any age from anywhere in the world with a suspected or confirmed PCD. A baseline questionnaire assesses details on PCD diagnosis, habitual symptoms and COVID-19 episodes that occurred before study entry. Afterwards, participants receive a weekly follow-up questionnaire with questions on incident severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, current symptoms, social contact behaviour and physical activity. Occasional thematic questionnaires are sent out focussing on emerging questions of interest chosen by people with PCD. In case of hospitalisation, patients or family members are asked to obtain a hospital report. Results are continuously analysed and summaries put online. The study started recruitment on April 30, 2020, and 556 people with PCD completed the baseline questionnaire by November 2, 2020. The COVID-PCD study is a participatory study that follows people with PCD during the COVID-19 pandemic, helps to empower affected persons, and serves as a platform for communication between patients, physicians and researchers.

A Qualitative Assessment of Bone Mineral Density in Individuals With Hemifacial Microsomia: A Cone-Beam Computed Tomography Study

OBJECTIVE

The purpose of this study is to utilize cone-beam computed tomography (CBCT) to compare the bone mineral density (BMD) on the affected versus nonaffected side, among individuals with hemifacial microsomia (HFM).

METHODS

This retrospective study included 9 patients with HFM. Pretreatment CBCT volumes were imported into Invivo5 software, which was used to measure BMD through Hounsfield units (HU) in 3 regions of the mandible; inferior to the lower lateral incisors, inferior to the first molar and at the ramus inferior to the sigmoid notch. Each region was measured at the buccal cortical bone, lingual cortical bone, and cancellous bone. The densities on the right and left sides were compared by Wilcoxon signed-rank test.

RESULTS

Overall, the BMD on the affected side tended to show slightly lower values when compared with the nonaffected side. Differences ranged from 14 HU at the lingual cortical plate of the first molar region to 234 HU at the buccal cortical plate of the ramus region. Differences were only statistically significant at the ramus region for the buccal (P = .002) and lingual (P < .001) cortical plates and at the lower incisor region at the buccal cortical plate (P = .016) and cancellous bone (P = .044). The differences, however, did not seem to be clinically significant.

CONCLUSIONS

The current study shows that the quality of bone on the affected side may be slightly reduced but did not seem to be clinically significant. This should be accounted for during surgical and orthodontic planning for patients with HFM.

'There and Back Again'-Forward Genetics and Reverse Phenotyping in Pulmonary Arterial Hypertension

Although the invention of right heart catheterisation in the 1950s enabled accurate clinical diagnosis of pulmonary arterial hypertension (PAH), it was not until 2000 when the landmark discovery of the causative role of bone morphogenetic protein receptor type II (BMPR2) mutations shed new light on the pathogenesis of PAH. Since then several genes have been discovered, which now account for around 25% of cases with the clinical diagnosis of idiopathic PAH. Despite the ongoing efforts, in the majority of patients the cause of the disease remains elusive, a phenomenon often referred to as "missing heritability". In this review, we discuss research approaches to uncover the genetic architecture of PAH starting with forward phenotyping, which in a research setting should focus on stable intermediate phenotypes, forward and reverse genetics, and finally reverse phenotyping. We then discuss potential sources of "missing heritability" and how functional genomics and multi-omics methods are employed to tackle this problem.

Molecular Surgery: Proteomics of a Rare Genetic Disease Gives Insight into Common Causes of Blindness

Rare diseases are an emerging global health priority. Although individually rare, the prevalence of rare "orphan" diseases is high, affecting approximately 300 million people worldwide. Treatments for these conditions are often inadequate, leaving the disease to progress unabated. Here, we review the clinical features and pathophysiology of neovascular inflammatory vitreoretinopathy (NIV), a rare inflammatory retinal disease caused by mutations in the CAPN5 gene. Although the prevalence of NIV is low (1 in 1,000,000 people), the disease mimics more common causes of blindness (e.g. uveitis, retinitis pigmentosa, proliferative diabetic retinopathy, and proliferative vitreoretinopathy) at distinct clinical stages. There is no cure for NIV to date. We highlight how personalized proteomics helped identify potential stage-specific biomarkers and drug targets in liquid vitreous biopsies. The NIV vitreous proteome revealed enrichment of molecular pathways associated with common retinal pathologies and implicated superior targets for therapeutic drug repositioning. In addition, we review our pipeline for collecting, storing, and analyzing ophthalmic surgical samples. This approach can be adapted to treat a variety of rare genetic diseases.

Interviews with experts in rare diseases for the development of clinical decision support system software - a qualitative study

BACKGROUND

Patients with rare diseases (RDs) are often diagnosed too late or not at all. Clinical decision support systems (CDSSs) could support the diagnosis in RDs. The MIRACUM (Medical Informatics in Research and Medicine) consortium, which is one of four funded consortia in the German Medical Informatics Initiative, will develop a CDSS for RDs based on distributed clinical data from ten university hospitals. This qualitative study aims to investigate (1) the relevant organizational conditions for the operation of a CDSS for RDs when diagnose patients (e.g. the diagnosis workflow), (2) which data is necessary for decision support, and (3) the appropriate user group for such a CDSS.

METHODS

Interviews were carried out with RDs experts. Participants were recruited from staff physicians at the Rare Disease Centers (RDCs) at the MIRACUM locations, which offer diagnosis and treatment of RDs. An interview guide was developed with a category-guided deductive approach. The interviews were recorded on an audio device and then transcribed into written form. We continued data collection until all interviews were completed. Afterwards, data analysis was performed using Mayring's qualitative content analysis approach.

RESULTS

A total of seven experts were included in the study. The results show that medical center guides and physicians from RDC B-centers (with a focus on different RDs) are involved in the diagnostic process. Furthermore, interdisciplinary case discussions between physicians are conducted. The experts explained that RDs exist which cannot be fully differentiated, but rather described only by their overall symptoms or findings: diagnosis is dependent on the disease or disease group. At the end of the diagnostic process, most centers prepare a summary of the patient case. Furthermore, the experts considered both physicians and experts from the B-centers to be potential users of a CDSS. The experts also have different experiences with CDSS for RDs.

CONCLUSIONS

This qualitative study is a first step towards establishing the requirements for the development of a CDSS for RDs. Further research is necessary to create solutions by also including the experts on RDs.

Comparison of the Pharyngeal Airway Volume Between Patients With Ectodermal Dysplasia and Unaffected Controls: A Cone-Beam Computed Tomography Study

PURPOSE

Ectodermal dysplasias (EDs) are a diverse set of hereditary conditions in which 2 or more ectodermal structures develop abnormally. The purpose of this study was to use cone-beam computed tomography (CBCT) scans to measure the pharyngeal airway volume and minimum cross-sectional area (MC) among patients with ED and compare them with healthy controls.

PATIENTS AND METHODS

The pretreatment CBCT scans of 9 individuals with ED and 61 controls were analyzed. Lateral cephalograms were created from the CBCT volumes and then traced and compared between the 2 groups. Airway volumes were evaluated by Dolphin 3D software (Dolphin Imaging, Chatsworth, CA) to compare the total pharyngeal volume, nasopharyngeal volume, oropharyngeal volume, hypopharyngeal volume, and MC. The mean airway volumes of the 2 groups were compared, and the odds ratio and relative risk of having an MC of less than 100 mm² in the ED group were calculated.

RESULTS

Intraclass correlation analysis showed excellent inter-rater reliability. All cephalometric features of controls were within the norms of patients with ideal skeletal-dental relationships. Patients with ED displayed significantly lower values for SNA (angle between sella-nasion and nasion-A point) (P = .018), ANB (angle between nasion-A point and nasion-B point) (P = .002), L1-MP (angle between long axis of mandibular incisor and gonion-menton plane) (P = .013), and L1-NB (distance between mandibular incisor and perpendicular line between nasion and B point) (P < .001). Although the ED group exhibited slightly smaller airway volumes for all subregions, the differences were not statistically significant for total pharyngeal volume, nasopharyngeal volume, oropharyngeal volume, hypopharyngeal volume, or MC (P > .05). The odds of having an MC of less than 100 mm² were almost 3 times greater among ED patients, and the relative risk of an MC of less than 100 mm² among ED patients was double that of controls.

CONCLUSIONS

Although the craniofacial structures of individuals with ED are characterized by maxillary and midface deficiency, the airway volumes among affected individuals may not be significantly different from those of unaffected controls. However, patients with ED displayed a higher risk of having an MC of less than 100 mm², which may be of clinical significance and warrants further investigations with larger samples.

Performance of matching methods in studies of rare diseases: a simulation study

Matching is a common method of adjusting for confounding in observational studies. Studies in rare diseases usually include small numbers of exposed subjects, but the performance of matching methods in such cases has not been evaluated thoroughly. In this study, we compare the performance of several matching methods when number of exposed subjects is small. We used Monte Carlo simulations to compare the following methods: Propensity score matching (PSM) with greedy or optimal algorithm, Mahalanobis distance matching, and mixture of PSM and exact matching. We performed the comparisons in datasets with six continuous and six binary variables, with varying effect size on group assignment and outcome. In each case, there were 1,500 unexposed subjects and a varying number of exposed: N = 25, 50, 100, 150, 200, 250, or 300. The probability of outcome in unexposed subjects was set to 5% (rare), 20% (common), or 50% (frequent). We compared the methods based on the bias of estimate of risk difference, coverage of 95% confidence intervals for risk difference, and balance of covariates. We observed a difference in performance of matching methods in very small samples (N = 25-50) and in moderately small samples (N = 100-300). Our study showed that PSM performs better than other matching methods when number of exposed subjects is small, but the matching algorithm and the matching ratio should be considered carefully. We recommend using PSM with optimal algorithm and one-to-five matching ratio in very small samples, and PSM matching with any algorithm and one-to-one matching in moderately small samples.

Human germline genome editing is illegal in Canada, but could it be desirable for some members of the rare disease community?

Human germline genome editing may prove to be especially poignant for members of the rare disease community, many of whom are diagnosed with monogenic diseases. This community lacks broad representation in the literature surrounding genome editing, notably in Canada, yet is likely to be directly affected by eventual clinical applications of this technology. Although not generalizable, the literature does offer some commonalities regarding the experiences of rare disease patients. This manuscript seeks to contribute to the search for broader societal dialogue surrounding human germline genome editing by exploring some of those commonalities that comfort the notion that CRISPR may hold promise or be desirable for some members of this community. We first explore the legal and policy context surrounding germline genome editing, focusing closely on Canada, then provide an overview of the common challenges experienced by members of the rare disease community, and finally assess the opportunities of germline genome editing vis-à-vis rare disease as we advocate for the need to more actively engage with the community in our search for public engagement.

Objectivity in rare disease research: A philosophical approach

Individuals living with rare conditions are faced with important challenges derived from the rarity of their conditions and aggravated by the low priority given to rare disease research. However, current realities of rare disease research require consideration of the relationship between subjectivity and 'traditional' objectivity. Objectivity in research has traditionally been associated with processes and descriptions that are independent of the investigator. The need for researchers to provide unbiased knowledge and achieve a balance between objectivity and the underlying values in nursing and scientific research requires an examination of how objectivity is conceptualized within the context of rare disease research. The aim of this paper is to examine scientific objectivity in rare disease research from a philosophical viewpoint and, in doing so, demonstrate the need to redefine it to reflect the current scientific environment. As such, healthcare providers working on this field need to redefine objectivity around ethical and moral obligation to advance science in an equitable manner with the end goal to produce knowledge that is trustworthy and beneficial to our patients.

Characterizing health state utilities associated with Duchenne muscular dystrophy: a systematic review

Background

Preferences for health states for Duchenne muscular dystrophy (DMD) are necessary to assess costs and benefits of novel therapies. Because DMD progression begins in childhood, the impact of DMD on health-related quality-of-life (HRQoL) affects preferences of both DMD patients and their families. The objective of this review was to synthesize published evidence for health state utility from the DMD patient and caregiver perspectives.

Methods

A systematic review was performed using MEDLINE and Embase, according to best practices. Data were extracted from studies reporting DMD patient or caregiver utilities; these included study and patient characteristics, health states considered, and utility estimates. Quality appraisal of studies was performed.

Results

From 888 abstracts, eight publications describing five studies were identified. DMD utility estimates were from preference-based measures presented stratified by ambulatory status, ventilation, and age. Patient (or patient–proxy) utility estimates ranged from 0.75 (early ambulatory DMD) to 0.05 (day-and-night ventilation). Caregiver utilities ranged from 0.87 (for caregivers of adults with DMD) to 0.71 (for caregivers of predominantly childhood patients). Both patient and caregiver utilities trended lower with higher disease severity. Variability in utilities was observed based on instrument, respondent type, and country. Utility estimates for health states within non-ambulatory DMD are under reported; nor were utilities for DMD-related health states such as scoliosis or preserved upper limb function identified.

Conclusion

Published health state utilities document the substantial HRQoL impacts of DMD, particularly with disease progression. Additional research in patient utilities for additional health states, particularly in non-ambulatory DMD patients, is warranted.

Electronic supplementary material

The online version of this article (10.1007/s11136-019-02355-x) contains supplementary material, which is available to authorized users.

Development of a pilot rare disease registry: a focus group study of initial steps towards the establishment of a rare disease ecosystem in Slovenia

BACKGROUND

According to rough estimates, there are approximately 150,000 rare disease patients in Slovenia (out of a total population of 2 million). Despite the absence of accurate epidemiological data on their status, these figures reveal the great importance of this area for the Slovenian healthcare system. Consistent monitoring in the field of rare diseases facilitates evidence-informed healthcare policies, comprehensive observation of rare disease patients, and consequently serves increasingly demanding medical and statistical needs. This paper initially explores the current situation concerning rare diseases and identifies related challenges for the planned development of a national rare disease registry in Slovenia. Based on the research findings, the paper outlines the construction of the pilot rare disease registry and conceptualizes the establishment of a rare disease ecosystem in Slovenia.

METHODS

The research is based on a case study design, where focus group sessions were used as the main data collection technique. Structured discussions were conducted with 24 eminent experts affiliated with the leading institutions in the field of rare diseases in Slovenia. Analysis and interpretations of the data obtained were carried by means of conventional content analysis. A subsequent course of action for developing the pilot rare disease registry and conceptualizing the rare disease ecosystem was formulated in collaboration with the experts participating in the focus groups.

RESULTS

The research results indicate that the effective development of the national rare disease registry, followed by the establishment of the rare disease ecosystem in Slovenia, requires a broad approach that entails a whole series of systemic changes and considerations. Moreover, well-orchestrated and well-funded efforts to achieve this goal should involve the coordinated action of all stakeholders, including the amendment of the regulatory framework, quality design, and enactment of a general rare disease policy, as well as the alignment of medical, organizational, and technological aspects in accordance with the long-term public healthcare objectives.

CONCLUSIONS

The establishment of a rare disease ecosystem in Slovenia and probably elsewhere, including a national rare disease registry, would represent an important improvement for patients, as it could significantly contribute to more coordinated healthcare treatment and enable comprehensive monitoring of the treatment process and results. A well-organized rare disease ecosystem could bring considerable benefits to healthcare system managers by providing a useful platform for estimating the required resources, evidence-informed policymaking, technological innovation, and organizational restructuring. This research provides valuable insight into the background of the issues that many countries face in the field of rare diseases, and ultimately provides practical recommendations for the development of national rare disease registries. However, ensuring effective healthcare delivery in this intricate field is critically dependent on the harmonization of digital solutions with other systemic factors and the adaptation of the rare disease ecosystem to the patients' needs and the specifics of the healthcare environment.

Inherited Retinal Disorders: Using Evidence as a Driver for Implementation

Incremental advances in the field of retinal genetics have transformed our understanding of inherited retinal disorders and have led to the development of powerful diagnostic tests and promising gene-based therapies. Despite this, successful integration of these developments into routine healthcare is frequently ineffective. Providing robust evidence of benefit can accelerate the implementation of clinical genetic interventions. For example, the adoption of a genetic test is much more likely when the test's clinical utility (i.e. its ability to influence management and health outcomes) has been clearly demonstrated. However, accruing such evidence for rare conditions like inherited retinal disorders is challenging. Conducting sufficiently powered studies requires both efficient study designs and large-scale, international collaboration. Reaching all populations and as many affected individuals as possible is key. Equally important are efforts to precisely and consistently capture phenotypic information, including natural history data. This article summarizes some of the current obstacles to implemen-tation and discusses approaches to overcome these barriers.