Longitudinal natural history studies based on real-world data in rare diseases: Opportunity and a novel approach.

Growing interest in therapeutic development for rare diseases necessitate a systematic approach to the collection and curation of natural history data that can be applied consistently across this group of heterogenous rare diseases. In this study, we discuss the challenges facing natural history studies for leukodystrophies and detail a novel standardized approach to creating a longitudinal natural history study using existing medical records. Prospective studies are uniquely challenging for rare diseases. Delays in diagnosis and overall rarity limit the timely collection of natural history data. When feasible, prospective studies are often cross-sectional rather than longitudinal and are unlikely to capture pre- or early- symptomatic disease trajectories, limiting their utility in characterizing the full natural history of the disease. Therapeutic development in leukodystrophies is subject to these same obstacles. The Global Leukodystrophy Initiative Clinical Trials Network (GLIA-CTN) comprises of a network of research institutions across the United States, supported by a multi-center biorepository protocol, to map the longitudinal clinical course of disease across leukodystrophies. As part of GLIA-CTN, we developed Standard Operating Procedures (SOPs) that delineated all study processes related to staff training, source documentation, and data sharing. Additionally, the SOP detailed the standardized approach to data extraction including diagnosis, clinical presentation, and medical events, such as age at gastrostomy tube placement. The key variables for extraction were selected through face validity, and common electronic case report forms (eCRF) across leukodystrophies were created to collect analyzable data. To enhance the depth of the data, clinical notes are extracted into "original" and "imputed" encounters, with imputed encounter referring to a historic event (e.g., loss of ambulation 3 months prior). Retrospective Functional Assessments were assigned by child neurologists, using a blinded dual-rater approach and score discrepancies were adjudicated by a third rater. Upon completion of extraction, data source verification is performed. Data missingness was evaluated using statistics. The proposed methodology will enable us to leverage existing medical records to address the persistent gap in natural history data within this unique disease group, allow for assessment of clinical trajectory both pre- and post-formal diagnosis, and promote recruitment of larger cohorts.

Systematic analysis of genotype-phenotype variability in siblings with Aicardi Goutières Syndrome (AGS).

OBJECTIVE: Aicardi Goutières Syndrome (AGS) is a genetic interferonopathy associated with multisystemic heterogeneous disease and neurologic dysfunction. AGS includes a broad phenotypic spectrum which is only partially explained by genotype. To better characterize this variability, we will perform a systematic analysis of phenotypic variability in familial cases of AGS. METHODS: Among thirteen families, twenty-six siblings diagnosed with AGS were identified from the Myelin Disorders and Biorepository Project (MDBP) at the Children's Hospital of Philadelphia. Data were collected on the age of onset, genotype, neurologic impairment, and systemic complications. Neurologic impairment was assessed by a disease-specific scale (AGS Severity Scale) at the last available clinical encounter (range: 0-11 representing severe - attenuated phenotypes). The concordance of clinical severity within sibling pairs was categorized based on the difference in AGS Scale (discordant defined as >2-unit difference). The severity classifications were compared between sibling sets and by genotype. RESULTS: Five genotypes were represented: TREX1 (n = 4 subjects), RNASEH2B (n = 8), SAMHD1 (n = 8) ADAR1 (n = 4), and IFIH1 (n = 2). The older sibling was diagnosed later relative to the younger affected sibling (median age 7.32 years [IQR = 14.1] compared to 1.54 years [IQR = 10.3]). Common presenting neurologic symptoms were tone abnormalities (n = 10/26) and gross motor dysfunction (n = 9/26). Common early systemic complications included dysphagia and chilblains. The overall cohort median AGS severity score at the last encounter was 8, while subjects presenting with symptoms before one year had a median score of 5. The TREX1 cohort presented at the youngest age and with the most severe phenotype on average. AGS scores were discordant for 5 of 13 sibling pairs, most commonly in the SAMHD1 pairs. Microcephaly, feeding tube placement, seizures and earlier onset sibling were associated with lower AGS scores (respectively, Wilcoxon rank sum: p = 0.0001, p < 0.0001, p = 0.0426, and Wilcoxon signed rank: p = 0.0239). CONCLUSIONS: In this systematic analysis of phenotypic variability in familial cases, we found discordance between siblings affected by AGS. Our results underscore the heterogeneity of AGS and suggest factors beyond AGS genotype may affect phenotype. Understanding the critical variables associated with disease onset and severity can guide future therapeutic interventions and clinical monitoring. This report reinforces the need for further studies to uncover potential factors to better understand this phenotypic variability, and consequently identify potential targets for interventions in attempt to change the natural history of the disease.

Gross Motor Function in Pediatric Onset TUBB4A-Related Leukodystrophy: GMFM-88 Performance and Validation of GMFC-MLD in TUBB4A.

TUBB4A pathogenic variants are associated with a spectrum of neurologic impairments including movement disorders and leukodystrophy. With the development of targeted therapies, there is an urgent unmet need for validated tools to measure mobility impairment. Our aim is to explore gross motor function in a pediatric-onset TUBB4A-related leukodystrophy cohort with existing gross motor outcome tools. Gross Motor Function Measure-88 (GMFM-88), Gross Motor Function Classification System (GMFCS-ER), and Gross Motor Function Classification-Metachromatic Leukodystrophy (GMFC-MLD) were selected through face validity. Subjects with a confirmed clinical and molecular diagnosis of TUBB4A-related leukodystrophy were enrolled. Participants' sex, age, genotype, and age at disease onset were collected, together with GMFM-88 and concurrent GMFCS-ER and GMFC-MLD. Performances on each measure were compared. GMFM-88 floor effect was defined as total score below 20%. A total of 35 subjects participated. Median performance by GMFM-88 was 16.24% (range 0-97.31), with 42.9% (n = 15) of individuals performing above the floor. GMFM-88 Dimension A (Lying and Rolling) was the best-performing dimension in the GMFM-88 (n = 29 above the floor). All levels of the Classification Scales were represented, with the exception of the GMFC-MLD level 0. Evaluation by GMFM-88 was strongly correlated with the Classification Scales (Spearman correlations: GMFCS-ER:GMFM-88 r = 0.90; GMFC-MLD:GMFM-88 r = 0.88; GMFCS-ER:GMFC-MLD: r = 0.92). Despite overall observation of a floor effect, the GMFM-88 is able to accurately capture the performance of individuals with attenuated phenotypes. GMFM-88 Dimension A shows no floor effect. GMFC-MLD shows a strong correlation with GMFCS-ER and GMFM-88, supporting its use as an age-independent functional score in TUBB4A-related leukodystrophy.

Racial and ethnic diversity of US participants in clinical trials for acne, atopic dermatitis, and psoriasis: a comprehensive review.

An increasing body of literature describes underreporting of race and ethnicity, and overrepresentation of White individuals in clinical trials. We aimed to evaluate the racial and ethnic diversity of US participants in clinical trials for acne, atopic dermatitis (AD), and psoriasis. We performed a comprehensive review of clinical trials for these common dermatologic diseases that were published between January 2014 and July 2019. Race and ethnicity reporting among all trials, and the racial and ethnic distribution of US participants were compared by skin disease, intervention type, and trial phase. In total, 103 articles representing 119 unique trials were evaluated. Race and ethnicity were reported in only 22.7% of trials. The proportion of White participants (77.5%) was higher than that of the US population (72.5%, p < .01); a finding largely driven by psoriasis trials (84.7% White). The proportions of non-White and Hispanic individuals in non-topical (21.0 and 16.3%, respectively) and Phase III (20.5 and 18.7%, respectively) trials were lower than those in topical (23.5 and 23.3%, respectively; p < .01) and Phase I/II trials (25.6 and 22.3%, respectively; p < .01). Race and ethnicity remain underreported in dermatologic clinical trials, and US trial participant diversity differs by skin disease, intervention type, and trial phase.

Patient Factors Associated With Teledermatology Visit Type and Submission of Photographs During the COVID-19 Pandemic: Cross-sectional Analysis.

BACKGROUND: The COVID-19 pandemic necessitated the widespread adoption of teledermatology, and this continues to account for a significant proportion of dermatology visits after clinics have reopened for in-person care. Delivery of high-quality teledermatology care requires adequate visualization of the patient's skin, with photographs being preferred over live video for remote skin examination. It remains unknown which patients face the greatest barriers to participating in a teledermatology visit with photographs. OBJECTIVE: The aim of this study was to identify patient characteristics associated with type of telemedicine visit and the factors associated with participating in teledermatology visits with digital photographs versus those without photographs. METHODS: We performed a cross-sectional analysis of the University of Pennsylvania Health System electronic health record data for adult patients who participated in at least 1 teledermatology appointment between March 1, 2020, and June 30, 2020. The primary outcomes were participation in a live-interactive video visit versus a telephone visit and participation in any teledermatology visit with photographs versus one without photographs. Multivariable logistic regression was performed to evaluate the associations between patient characteristics and the primary outcomes. RESULTS: In total, 5717 unique patients completed at least 1 teledermatology visit during the study period; 68.25% (n=3902) of patients participated in a video visit, and 31.75% (n=1815) participated in a telephone visit. A minority of patients (n=1815, 31.75%) submitted photographs for their video or telephone appointment. Patients who submitted photographs for their teledermatology visit were more likely to be White, have commercial insurance, and live in areas with higher income, better education, and greater access to a computer and high-speed internet (P<.001 for all). In adjusted analysis, older age (age group >75 years: odds ratio [OR] 0.60, 95% CI 0.44-0.82), male sex (OR 0.85, 95% CI 0.75-0.97), Black race (OR 0.79, 95% CI 0.65-0.96), and Medicaid insurance (OR 0.81, 95% CI 0.66-0.99) were each associated with lower odds of a patient submitting photographs for their video or telephone visit. Older age (age group >75 years: OR 0.37, 95% CI 0.27-0.50) and Black race (OR 0.82, 95% CI 0.68-0.98) were also associated with lower odds of a patient participating in a video visit versus telephone visit. CONCLUSIONS: Patients who were older, male, or Black, or who had Medicaid insurance were less likely to participate in teledermatology visits with photographs and may be particularly vulnerable to disparities in teledermatology care. Further research is necessary to identify the barriers to patients providing photographs for remote dermatology visits and to develop targeted interventions to facilitate equitable participation in teledermatology care.