Drivers of heterogeneity in synovial fibroblasts in rheumatoid arthritis.

Inflammation of non-barrier immunologically quiescent tissues is associated with a massive influx of blood-borne innate and adaptive immune cells. Cues from the latter are likely to alter and expand activated states of the resident cells. However, local communications between immigrant and resident cell types in human inflammatory disease remain poorly understood. Here, we explored drivers of fibroblast-like synoviocyte (FLS) heterogeneity in inflamed joints of patients with rheumatoid arthritis using paired single-cell RNA and ATAC sequencing, multiplexed imaging and spatial transcriptomics along with in vitro modeling of cell-extrinsic factor signaling. These analyses suggest that local exposures to myeloid and T cell-derived cytokines, TNF, IFN-γ, IL-1ß or lack thereof, drive four distinct FLS states some of which closely resemble fibroblast states in other disease-affected tissues including skin and colon. Our results highlight a role for concurrent, spatially distributed cytokine signaling within the inflamed synovium.

Placenta-Specific Transcripts Containing Androgen Response Elements Are Altered In Silico by Male Growth Outcomes.

A birthweight centile (BWC) below the 25th is associated with an elevated risk of adverse perinatal outcomes, particularly among males. This male vulnerability may stem from alterations in placenta-specific androgen signalling, a signalling axis that involves the androgen receptor (AR)-mediated regulation of target genes containing androgen response elements (AREs). In this study, we examined global and ARE-specific transcriptomic signatures in term male placentae (≥37 weeks of gestation) across BWC subcategories (<10th, 10th-30th, >30th) using RNA-seq and gene set enrichment analysis. ARE-containing transcripts in placentae with BWCs below the 10th percentile were upregulated compared to those in the 10th-30th and >30th percentiles, which coincided with the enrichment of gene sets related to hypoxia and the suppression of gene sets associated with mitochondrial function. In the absence of ARE-containing transcripts in silico, <10th and 10th-30th BWC subcategory placentae upregulated gene sets involved in vasculature development, immune function, and cell adhesion when compared to those in the >30th BWC subcategory. Collectively, our in silico findings suggest that changes in the expression of ARE-containing transcripts in male placentae may contribute to impaired placental vasculature and therefore result in reduced fetal growth outcomes.

Traditional versus virtual partial hospital programme for eating disorders: Feasibility and preliminary comparison of effects.

OBJECTIVE: Minimal research has examined teletherapy for group or intensive eating disorder (ED) treatment, particularly partial hospital programme (PHP). This study compared treatment outcomes for individuals treated before and after a pandemic-driven implementation of virtual PHP. METHOD: Patients received care at ED treatment centres using the Renfrew Unified Treatment for Eating Disorders and Comorbidity. Patients treated with virtual PHP were compared to patients treated with traditional PHP. Measures of ED symptomology and behaviours, depressive symptoms, anxiety severity, anxiety sensitivity, experiential avoidance, mindfulness, and body mass index (BMI; reported for anorexia nervosa [AN] patients only) were collected at intake and discharge. Multiple regression analyses were conducted to examine the effect of treatment group on outcomes, controlling for intake score, comorbidity, discharge status, AN diagnosis, and step-down status. RESULTS: Differences in treatment type were only found for binge eating frequency, with those in virtual PHP reporting significantly lower binge eating episodes at discharge than those in traditional PHP. Body mass index showed significantly less improvement in virtual PHP than in traditional PHP. CONCLUSIONS: Preliminary results suggest virtual PHP is feasible and effective, potentially increasing access to evidence-based, intensive ED treatment. However, additional research is needed to establish efficacious support for weight gain among individuals with AN in virtual programs.

One Year Into Dupilumab: Physician and Patient Experiences in Initiating Dupilumab for Pediatric Eosinophilic Esophagitis.

In 2022, the US Food and Drug Administration approved dupilumab for treatment of eosinophilic esophagitis (EoE). The aims of this study were to report physician and patient perspectives on initiating dupilumab. A 2-pronged approach was used: (1) data on physician prescribing practices was gathered via retrospective chart review of EoE patients prescribed dupilumab and (2) pediatric patients on dupilumab were approached to complete a questionnaire regarding reasons for initiation. During this time, 42 patients were prescribed dupilumab. From the physician's perspective, the primary reasons for dupilumab included nonresponse to topical corticosteroids (TCS) (52%), nonadherence (28%), adverse effects (10%), or to treat multiple atopic diseases (5%). The median dupilumab initiation time, from day prescribed to first injection, was 37 days [interquartile range (IQR) 37]. Almost all required prior authorization (PA) (98%), while 17% required letter of appeal and 2% required peer-to-peer. Fifteen patients (36%) completed the questionnaire portion of the study. From the patient's perspective, the primary reasons for dupilumab initiation included nonresponse to TCS (27%), nonadherence to TCS (27%), concern about adverse effects of TCS (7%), and treatment of multiple atopic diseases (33%). In conclusion, physicians are prescribing dupilumab primarily for nonresponse to TCS and almost all required PA with a long delay to starting dupilumab.

Trajectories of interpersonal problems in residential eating disorder treatment: Exploring the influence of primary diagnosis.

Baseline interpersonal problems have been associated with treatment outcome in eating disorders (ED) and are important for understanding ED maintenance and aetiology. Despite this evidence, little is known about trajectories of change in interpersonal problems in the context of treatment, particularly in intensive ED treatment. This study examined the trajectory of total interpersonal problems in residential ED treatment, as well as two subdomains previously highlighted in ED research of being overly Cold (interpersonally distant) or overly Domineering (interpersonally controlling), as a function of different primary presenting ED diagnoses: anorexia nervosa restricting subtype (AN-R), binge-purge subtype (AN-BP), and bulimia nervosa or binge eating (BN/BED). Interpersonal problem data were collected at admission, discharge, and 6-month follow-up. Trajectories were analysed with multilevel models. Results showed small-to-medium statistically significant reductions in interpersonal problems across diagnostic groups from admission to discharge for total interpersonal scores, and gains appeared to be maintained at follow-up for both AN groups. Patients diagnosed with primary AN experienced steeper declines in total interpersonal problems from admission to follow-up compared with patients diagnosed with BN/BED, with AN-R experiencing the steepest trajectory. Planned contrasts indicated anyone with relevant binge eating behaviours had higher average levels of both Cold, as well as Domineering problems. Exploratory contrasts suggested that patients who had more Domineering problems also exhibited more binge symptoms and were typically slower to improve. Overall, results suggest interpersonal problems are generally malleable in residential ED treatment, yet change patterns differ by presenting ED symptoms and interpersonal problem subdomain.

Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere.

For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species-season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds.

Increasing the Specificity of AAV-Based Gene Editing through Self-Targeting and Short-Promoter Strategies.

Our group previously used adeno-associated viral vectors (AAVs) to express an engineered meganuclease specific for a sequence in the PCSK9 gene (M2PCSK9), a clinical target for treating coronary heart disease. Upon testing this nuclease in non-human primates, we observed specific editing characterized by several insertions and deletions (indels) in the target sequence as well as indels in similar genomic sequences. We hypothesized that high nuclease expression increases off-target editing. Here, we reduced nuclease expression using two strategies. The first was a self-targeting strategy that involved inserting the M2PCSK9 target sequence into the AAV genome that expresses the nuclease and/or fusing the nuclease to a specific peptide to promote its degradation. The second strategy used a shortened version of the parental promoter to reduce nuclease expression. Mice administered with these second-generation AAV vectors showed reduced PCSK9 expression due to the nuclease on-target activity and reduced off-target activity. All vectors induced a stable reduction of PCSK9 in primates treated with self-targeting and short-promoter AAVs. Compared to the meganuclease-expressing parental AAV vector, we observed a significant reduction in off-target activity. In conclusion, we increased the in vivo nuclease specificity using a clinically relevant strategy that can be applied to other genome-editing nucleases.

Circular RNAs in Pregnancy and the Placenta.

The emerging field of circular RNAs (circRNAs) has identified their novel roles in the development and function of many cancers and inspired the interest of many researchers. circRNAs are also found throughout the healthy body, as well as in other pathological states, but while research into the function and abundance of circRNAs has progressed, our overall understanding of these molecules remains primitive. Importantly, recent studies are elucidating new roles for circRNAs in pregnancy, particularly in the placenta. Given that many of the genes responsible for circRNA production in cancer are also highly expressed in the placenta, it is likely that the same genes act in the production of circRNAs in the placenta. Furthermore, placental development can be referred to as 'controlled cancer', as it shares many key signalling pathways and hallmarks with tumour growth and metastasis. Hence, the roles of circRNAs in this field are important to study with respect to pregnancy success but also may provide novel insights for cancer progression. This review illuminates the known roles of circRNAs in pregnancy and the placenta, as well as demonstrating differential placental expressions of circRNAs between complicated and uncomplicated pregnancies.

Placental Transcription Profiling in 6-23 Weeks' Gestation Reveals Differential Transcript Usage in Early Development.

The human placenta is a rapidly developing transient organ that is key to pregnancy success. Early development of the conceptus occurs in a low oxygen environment before oxygenated maternal blood begins to flow into the placenta at ~10-12 weeks' gestation. This process is likely to substantially affect overall placental gene expression. Transcript variability underlying gene expression has yet to be profiled. In this study, accurate transcript expression profiles were identified for 84 human placental chorionic villus tissue samples collected across 6-23 weeks' gestation. Differential gene expression (DGE), differential transcript expression (DTE) and differential transcript usage (DTU) between 6-10 weeks' and 11-23 weeks' gestation groups were assessed. In total, 229 genes had significant DTE yet no significant DGE. Integration of DGE and DTE analyses found that differential expression patterns of individual transcripts were commonly masked upon aggregation to the gene-level. Of the 611 genes that exhibited DTU, 534 had no significant DGE or DTE. The four most significant DTU genes ADAM10, VMP1, GPR126, and ASAH1, were associated with hypoxia-responsive pathways. Transcript usage is a likely regulatory mechanism in early placentation. Identification of functional roles will facilitate new insight in understanding the origins of pregnancy complications.

Rheumatology in the era of precision medicine: synovial tissue molecular patterns and treatment response in rheumatoid arthritis.

PURPOSE OF REVIEW: A critical unmet need in rheumatoid arthritis (RA) is the identification of biomarkers that predict which of the available medications will be most effective for an individual in order to lower disease activity sooner than is afforded by the current treat-to-target approach. Here we will discuss recent reports examining the potential for synovial tissue molecular, cellular, and spatial profiling in defining objective measures of treatment response and therein developing personalized medicine for RA. RECENT FINDINGS: Recent high-dimensional molecular profiling of RA synovium has provided unprecedented resolution of the cell types and pathways in tissues affected by rheumatic diseases. Heightened attention to tissue architecture is also emerging as a means to classify individual disease variation that may allow patients to be further stratified by therapeutic response. Although this wealth of data may have already pinpointed promising biomarkers, additional studies, likely including tissue-based functional drug response assays, will be required to demonstrate how the complex tissue environment responds. SUMMARY: Molecular, cellular, and more recently spatial profiling of the RA synovium are uncovering fundamental features of the disease. Current investigations are examining whether this information will provide meaningful biomarkers for individualized medicine in RA.

Muscle-directed AAV gene therapy rescues the maple syrup urine disease phenotype in a mouse model.

Maple syrup urine disease (MSUD) is a rare, inherited metabolic disorder characterized by a dysfunctional mitochondrial enzyme complex, branched-chain alpha-keto acid dehydrogenase (BCKDH), which catabolizes branched-chain amino acids (BCAAs). Without functional BCKDH, BCAAs and their neurotoxic alpha-keto intermediates can accumulate in the blood and tissues. MSUD is currently incurable and treatment is limited to dietary restriction or liver transplantation, meaning there is a great need to develop new treatments for MSUD. We evaluated potential gene therapy applications for MSUD in the intermediate MSUD (iMSUD) mouse model, which harbors a mutation in the dihydrolipoamide branched-chain transacylase E2 (DBT) subunit of BCKDH. Systemic delivery of an adeno-associated virus (AAV) vector expressing DBT under control of the liver-specific TBG promoter to the liver did not sufficiently ameliorate all aspects of the disease phenotype. These findings necessitated an alternative therapeutic strategy. Muscle makes a larger contribution to BCAA metabolism than liver in humans, but a muscle-specific approach involving a muscle-specific promoter for DBT expression delivered via intramuscular (IM) administration only partially rescued the MSUD phenotype in mice. Combining the muscle-tropic AAV9 capsid with the ubiquitous CB7 promoter via IM or IV injection, however, substantially increased survival across all assessed doses. Additionally, near-normal serum BCAA levels were achieved and maintained in the mid- and high-dose cohorts throughout the study; this approach also protected these mice from a lethal high-protein diet challenge. Therefore, administration of a gene therapy vector that expresses in both muscle and liver may represent a viable approach to treating patients with MSUD.

Large-scale transcriptome-wide profiling of microRNAs in human placenta and maternal plasma at early to mid gestation.

MicroRNAs (miRNAs) are increasingly seen as important regulators of placental development and opportunistic biomarker targets. Given the difficulty in obtaining samples from early gestation and subsequent paucity of the same, investigation of the role of miRNAs in early gestation human placenta has been limited. To address this, we generated miRNA profiles using 96 placentas from presumed normal pregnancies, across early gestation, in combination with matched profiles from maternal plasma. Placenta samples range from 6 to 23 weeks' gestation, a time period that includes placenta from the early, relatively low but physiological (6-10 weeks' gestation) oxygen environment, and later, physiologically normal oxygen environment (11-23 weeks' gestation).We identified 637 miRNAs with expression in 86 samples (after removing poor quality samples), showing a clear gestational age gradient from 6 to 23 weeks' gestation. We identified 374 differentially expressed (DE) miRNAs between placentas from 6-10 weeks' versus 11-23 weeks' gestation. We see a clear gestational age group bias in miRNA clusters C19MC, C14MC, miR-17 ~ 92 and paralogs, regions that also include many DE miRNAs. Proportional change in expression of placenta-specific miRNA clusters was reflected in maternal plasma.The presumed introduction of oxygenated maternal blood into the placenta (between ~10 and 12 weeks' gestation) changes the miRNA profile of the chorionic villus, particularly in placenta-specific miRNA clusters. Data presented here comprise a clinically important reference set for studying early placenta development and may underpin the generation of minimally invasive methods for monitoring placental health.

Metal Toxicity and Resistance in Plants and Microorganisms in Terrestrial Ecosystems.

Metals are major abiotic stressors of many organisms, but their toxicity in plants is not as studied as in microorganisms and animals. Likewise, research in plant responses to metal contamination is sketchy. Candidate genes associated with metal resistance in plants have been recently discovered and characterized. Some mechanisms of plant adaptation to metal stressors have been now decrypted. New knowledge on microbial reaction to metal contamination and the relationship between bacterial, archaeal, and fungal resistance to metals has broadened our understanding of metal homeostasis in living organisms. Recent reviews on metal toxicity and resistance mechanisms focused only on the role of transcriptomics, proteomics, metabolomics, and ionomics. This review is a critical analysis of key findings on physiological and genetic processes in plants and microorganisms in responses to soil metal contaminations.

Balanced Crystalloids Versus Saline in Critically Ill Adults: A Systematic Review and Meta-analysis.

Background: The optimal resuscitative fluid remains controversial. Objective: To assess the association between crystalloid fluid and outcomes in critically ill adults. Methods: Cumulative Index to Nursing and Allied Health Literature, Scopus, PubMed, and Cochrane Central Register for Controlled Trials were searched from inception through July 2019. Cohort studies and randomized trials of critically ill adults provided predominantly nonperioperative fluid resuscitation with balanced crystalloids or 0.9% sodium chloride (saline) were included. Results: Thirteen studies (n = 30 950) were included. Balanced crystalloids demonstrated lower hospital or 28-/30-day mortality (risk ratio [RR] = 0.86; 95% CI = 0.75-0.99; I2 = 82%) overall, in observational studies (RR = 0.64; 95% CI = 0.41-0.99; I2 = 63%), and approached significance in randomized trials (RR = 0.94; 95% CI = 0.88-1.02; I2 = 0%). New acute kidney injury occurred less frequently with balanced crystalloids (RR = 0.91; 95% CI = 0.85-0.98; I2 = 0%), though progression to renal replacement therapy was similar (RR = 0.91; 95% CI = 0.79-1.04; I2 = 38%). In the sepsis cohort, odds of hospital or 28-/30-day mortality were similar, but the odds of major adverse kidney events occurring in the first 30 days were less with balanced crystalloids than saline (OR = 0.78; 95% CI = 0.66-0.91; I2 = 42%). Conclusion and Relevance: Resuscitation with balanced crystalloids demonstrated lower hospital or 28-/30-day mortality compared with saline in critically ill adults but not specifically those with sepsis. Balanced crystalloids should be provided preferentially to saline in most critically ill adult patients.

Midodrine as an Adjuvant to Intravenous Vasopressor Agents in Adults With Resolving Shock: Systematic Review and Meta-Analysis.

PURPOSE: To evaluate the effects of midodrine in addition to intravenous vasopressor therapy on outcomes in adults recovering from shock. MATERIALS AND METHODS: PubMed, Scopus, Clinicaltrials.gov, and published abstracts were searched from inception to November 2018 for studies comparing outcomes in shock after midodrine initiation versus no midodrine. RESULTS: Three studies with 2533 patients were included. Patients in whom midodrine was added to intravenous vasopressor therapy compared to intravenous vasopressor therapy alone experienced similar intensive care unit (ICU; mean difference [MD]: 1.38 days, 95% confidence interval [CI]: -3.48 to 6.23, I2 = 93%) and hospital lengths of stay (MD: 4.37 days, 95% CI: -3.45 to 12.19, I2 = 93%) and intravenous vasopressor duration after midodrine initiation (MD: 7.28 days, 95% CI: -0.86 to 15.41, I2 = 97%). Mortality was similar between groups (odds ratio: 0.74, 95% CI: 0.44-1.27, I2 = 65%). Qualitative assessment of reporting biases revealed minimal location bias, moderate selective outcome reporting bias, no selective analysis reporting bias, and no conflict of interest bias. CONCLUSIONS: Midodrine had no effect on ICU or hospital length of stay. These results were highly susceptible to the study heterogeneity and availability. Future investigation into standardized initiation of midodrine at an adequate dosage with an expedited titration strategy is needed in order to assess the utility of this strategy in shock management.

Stability and Extraction of Vanillin and Coumarin under Subcritical Water Conditions.

In order to facilitate the development of the green subcritical water chromatography technique for vanillin and coumarin, the stability of the compounds under subcritical water conditions was investigated in this work. In addition, their extraction from natural products was also studied. The stability experiments were carried out by heating the mixtures of vanillin and water or coumarin and water at temperatures ranging from 100 °C to 250 °C, while subcritical water extractions (SBWE) of both analytes from vanilla beans and whole tonka beans were conducted at 100 °C to 200 °C. Analyte quantification for both stability and extraction studies was carried out by HPLC. After heating for 60 min, vanillin was found to be stable in water at temperatures up to 250 °C. While coumarin is also stable at lower temperatures such as 100 °C and 150 °C, it undergoes partial degradation after heating for 60 min at 200 °C and higher. The results of this stability study support green subcritical water chromatographic separation and extraction of vanillin and coumarin at temperatures up to 150 °C. The SBWE results revealed that the extraction efficiency of both analytes from vanilla beans and tonka beans is significantly improved with increasing temperature.

Systematic Review of the Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screening for MRSA Pneumonia.

OBJECTIVE: To describe the diagnostic performance characteristics of methicillin-resistant Staphylococcus aureus (MRSA) nasal screening for patients with pneumonia. DATA SOURCES: PubMed and Scopus were searched from 1 January 1990 to 12 December 2018 using terms methicillin-resistant Staphylococcus aureus AND (screening OR active surveillance OR surveillance culture OR targeted surveillance OR chromogenic OR PCR OR polymerase chain reaction OR rapid test) AND (nares OR nasal) AND (pneumonia OR respiratory). STUDY SELECTION AND DATA EXTRACTION: Relevant studies in humans and English were considered. DATA SYNTHESIS: In all, 19 studies, including 21 790 patients, were included. Nasal screening for MRSA had a high negative predictive value (NPV; 76% to 99.4% for relevant studies) across all types of pneumonia. Time from nasal screening to culture varied across studies. Relevance to Patient Care and Clinical Practice: MRSA nasal screening has a high NPV for MRSA involvement in pneumonia. Utilizing this test for antimicrobial stewardship program (ASP) purposes can provide a valuable tool for reducing unwarranted anti-MRSA agents and may provide additional cost benefits. A cutoff of 7 days between nasal swab and culture or infection onset seems most appropriate for use of this test for anti-MRSA agent de-escalation for ASP purposes. CONCLUSIONS: Consideration for the inclusion of the utility of MRSA nasal screening in MRSA pneumonia should be made for future pneumonia and ASP guidelines. Additional studies are warranted to fully evaluate specific pneumonia classifications, culture types, culture timing, and clinical outcomes associated with the use of this test in patients with pneumonia.

Safety, efficacy, and cost of four-factor prothrombin complex concentrate (4F-PCC) in patients with factor Xa inhibitor-related bleeding: a retrospective study.

Oral factor Xa (fXa) inhibitor-related bleeding is a concerning drug safety problem. There is considerable controversy surrounding available reversal strategies. The recently approved reversal agent andexanet alfa has limited data, an unclear safety profile, and imparts a substantial financial burden. This has led to the off-label use of four-factor prothrombin complex concentrates (4F-PCC) for this indication. This study aimed to assess the safety and efficacy of 4F-PCC for the management of major bleeding related to oral fXa inhibitors. This observational, retrospective study included adult patients admitted from 2014 to 2018 who received 4F-PCC (Kcentra®) for fXa inhibitor-related major bleeding. Efficacy was assessed using criteria described by Sarode et al. Secondary outcomes included the incidence of thromboembolism, mortality, and a cost analysis comparing 4F-PCC to andexanet alfa for reversal of oral fXa inhibitors. Thirty-one patients received 4F-PCC for major bleeding associated with apixaban (55%) or rivaroxaban (45%). Intracranial hemorrhage (58%) and pericardial effusion (16%) accounted for the majority of bleeding events. Most patients received a single weight-based 4F-PCC dose of 25 units/kg (38.7%) or 50 units/kg (51.6%). Effective hemostasis was achieved in 80.6% of patients. Five patients (16%) died due to acute bleeding and no thromboembolic events were observed. Administration of 4F-PCC was effective for most patients requiring emergent reversal of anticoagulation with apixaban or rivaroxaban and was associated with a low risk of thromboembolic events. Considerable cost differences limit the use of andexanet alfa and may warrant further study of 4F-PCC for fXa inhibitor reversal.

FMR1 allele size distribution in 35,000 males and females: a comparison of developmental delay and general population cohorts.

PURPOSE: Developmental delay phenotypes have been associated with FMR1 premutation (PM: 55-200 CGG repeats) and "gray zone" (GZ: 45-54 CGG repeats) alleles. However, these associations have not been confirmed by larger studies to be useful in pediatric diagnostic or screening settings. METHODS: This study determined the prevalence of PM and GZ alleles in two independent cohorts of 19,076 pediatric referrals to developmental delay diagnostic testing through Victorian Clinical Genetics Service (cohort 1: N = 10,235; cohort 2: N = 8841), compared with two independent general population cohorts (newborn screening N = 1997; carrier screening by the Victorian Clinical Genetics Service prepair program N = 14,249). RESULTS: PM and GZ prevalence rates were not significantly increased (p > 0.05) in either developmental delay cohort (male PM: 0.12-0.22%; female PM: 0.26-0.33%; male GZ: 0.68-0.69%; female GZ: 1.59-2.13-%) compared with general population cohorts (male PM: 0.20%; female PM: 0.27-0.82%; male GZ: 0.79%; female GZ: 1.43-2.51%). Furthermore, CGG size distributions were comparable across datasets, with each having a modal value of 29 or 30 and ~1/3 females and ~1/5 males having at least one allele with ≤26 CGG repeats. CONCLUSION: These data do not support the causative link between PM and GZ expansions and developmental-delay phenotypes in pediatric settings.

Correction: Reproductive genetic carrier screening for cystic fibrosis, fragile X syndrome, and spinal muscular atrophy in Australia: outcomes of 12,000 tests.

Zoe McDonald, BSc, was omitted from the list of article coauthors. Her name should have been included as the seventh author, following Clare Elizabeth Hunt. Her affiliation is Victorian Clinical Genetics Services, Parkville, Victoria, Australia. The authors regret the error.