Longitudinal trajectories of a claims-based frailty measure during adjuvant chemotherapy in women with stage I-III breast cancer.

BACKGROUND: Frailty is a dynamic syndrome characterized by reduced physiological reserve to maintain homeostasis. Prospective studies have reported frailty worsening in women with breast cancer during chemotherapy, with improvements following treatment. We evaluated whether the Faurot frailty index, a validated claims-based frailty measure, could identify changes in frailty during chemotherapy treatment and identified predictors of trajectory patterns. METHODS: We included women (65+ years) with stage I-III breast cancer undergoing adjuvant chemotherapy in the SEER-Medicare database (2003-2019). We estimated the Faurot frailty index (range: 0-1; higher scores indicate greater frailty) at chemotherapy initiation, 4 months postinitiation, and 10 months postinitiation. Changes in frailty were compared to a matched noncancer comparator cohort. We identified patterns of frailty trajectories during the year following chemotherapy initiation using K-means clustering. RESULTS: Twenty-one thousand five hundred and ninety-nine women initiated adjuvant chemotherapy. Mean claims-based frailty increased from 0.037 at initiation to 0.055 4 months postchemotherapy initiation and fell to 0.049 10 months postinitiation. Noncancer comparators experienced a small increase in claims-based frailty over time (0.055-0.062). We identified 6 trajectory patterns: a robust group (78%), 2 resilient groups (16%), and 3 nonresilient groups (6%). Black women and women with claims for home hospital beds, wheelchairs, and Parkinson's disease were more likely to experience nonresilient trajectories. CONCLUSIONS: We observed changes in a claims-based frailty index during chemotherapy that are consistent with prior studies using clinical measures of frailty and identified predictors of nonresilient frailty trajectories. Our study demonstrates the feasibility of using claims-based frailty indices to assess changes in frailty during cancer treatment.

Performance of a Claims-Based Frailty Proxy Using Varying Frailty Ascertainment Lookback Windows.

BACKGROUND: Frailty is an aging-related syndrome of reduced physiological reserve to maintain homeostasis. The Faurot frailty index has been validated as a Medicare claims-based proxy for predicting frailty using billing information from a user-specified ascertainment window. OBJECTIVES: We assessed the validity of the Faurot frailty index as a predictor of the frailty phenotype and 1-year mortality using varying frailty ascertainment windows. RESEARCH DESIGN: We identified older adults (66+ y) in Round 5 (2015) of the National Health and Aging Trends Study with Medicare claims linkage. Gold standard frailty was assessed using the frailty phenotype. We calculated the Faurot frailty index using 3, 6, 8, and 12 months of claims prior to the survey or all-available lookback. Model performance for each window in predicting the frailty phenotype was assessed by quantifying calibration and discrimination. Predictive performance for 1-year mortality was assessed by estimating risk differences across claims-based frailty strata. RESULTS: Among 4253 older adults, the 6 and 8-month windows had the best frailty phenotype calibration (calibration slopes: 0.88 and 0.87). All-available lookback had the best discrimination (C-statistic=0.780), but poor calibration. Mortality associations were strongest using a 3-month window and monotonically decreased with longer windows. Subgroup analyses revealed worse performance in Black and Hispanic individuals than counterparts. CONCLUSIONS: The optimal ascertainment window for the Faurot frailty index may depend on the clinical context, and researchers should consider tradeoffs between discrimination, calibration, and mortality. Sensitivity analyses using different durations can enhance the robustness of inferences. Research is needed to improve prediction across racial and ethnic groups.

The association between wealth and sleep medication use in a nationally-representative sample of older Medicare beneficiaries.

BACKGROUND: Sleep disorders are common among older adults, leading to high prevalence of over-the-counter and prescription sleep medication use. Socioeconomically disadvantaged individuals have higher prevalence of sleep disorders. Frequent use of sleep medications can increase the risk of falls. Little is known about the association between wealth and sleep medication use in older adults. METHODS: We conducted a cross-sectional analysis using a nationwide sample of 7603 Medicare beneficiaries (65+ years) from Round 1 (2011) of the National Health and Aging Trends Study. We measured self-reported wealth as the sum of assets (retirement savings, stocks/bonds, checking/savings accounts, business assets, and home value) minus liabilities (mortgage, credit card, and medical debt). Self-reported sleep medication use in the past month was categorized as frequent (5-7 nights/week), sometimes (1-4 nights/week), or never (0 night/week). We estimated differences in the prevalence of sleep medication use by quintiles of wealth using crude and adjusted binomial regression models. Individuals missing sleep medication information were excluded. RESULTS: Median wealth was $152 582 (IQR: $24 023-412 992). Sixteen percent reported frequent sleep medication use, 15% reported some use, and 70% reported no use. Frequent sleep medication use was more common in lower wealth quintiles (lowest: 20%, highest: 12%). Alternatively, some use was more common in higher wealth quintiles (lowest: 11%, highest: 18%). Results were similar after adjustment for demographic factors, anxiety, depression, and sleep disorders. CONCLUSIONS: In this study, less wealthy older adults had higher prevalence of frequent sleep medication use. This may lead to dependency or increased fall risk in this vulnerable population.

Translation of a Claims-Based Frailty Index From the International Classification of Diseases, Ninth Revision, Clinical Modification to the Tenth Revision.

The Faurot frailty index (FFI) is a validated algorithm that uses enrollment and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-based billing information from Medicare claims data as a proxy for frailty. In October 2015, the US health-care system transitioned from the ICD-9-CM to the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). Applying the Centers for Medicare and Medicaid Services General Equivalence Mappings, we translated diagnosis-based frailty indicator codes from the ICD-9-CM to the ICD-10-CM, followed by manual review. We used interrupted time-series analysis of Medicare data to assess the comparability of the pre- and posttransition FFI scores. In cohorts of beneficiaries enrolled in January 2015-2017 with 8-month frailty look-back periods, we estimated associations between the FFI and 1-year risk of aging-related outcomes (mortality, hospitalization, and admission to a skilled nursing facility). Updated indicators had similar prevalences as pretransition definitions. The median FFI scores and interquartile ranges (IQRs) for the predicted probability of frailty were similar before and after the International Classification of Diseases transition (pretransition: median, 0.034 (IQR, 0.02-0.07); posttransition: median, 0.038 (IQR, 0.02-0.09)). The updated FFI was associated with increased risks of mortality, hospitalization, and skilled nursing facility admission, similar to findings from the ICD-9-CM era. Studies of medical interventions in older adults using administrative claims should use validated indices, like the FFI, to mitigate confounding or assess effect-measure modification by frailty.

Disseminated Coccidioidomycosis Treated with Interferon-γ and Dupilumab.

We describe a case of life-threatening disseminated coccidioidomycosis in a previously healthy child. Like most patients with disseminated coccidioidomycosis, this child had no genomic evidence of any known, rare immune disease. However, comprehensive immunologic testing showed exaggerated production of interleukin-4 and reduced production of interferon-γ. Supplementation of antifungal agents with interferon-γ treatment slowed disease progression, and the addition of interleukin-4 and interleukin-13 blockade with dupilumab resulted in rapid resolution of the patient's clinical symptoms. This report shows that blocking of type 2 immune responses can treat infection. This immunomodulatory approach could be used to enhance immune clearance of refractory fungal, mycobacterial, and viral infections. (Supported by the Jeffrey Modell Foundation and the National Institutes of Health.).

Preferred Feedback Styles Among Different Groups in an Academic Medical Center.

INTRODUCTION: Feedback is an essential component in complex work environments. Different generations have been shown to have different sets of values, derived from societal and cultural changes. We hypothesize that generational differences may be associated with preferred feedback patterns among medical trainees and faculty in a large academic institution. METHODS: A survey was distributed to all students, residents/fellows, and faculty at a large academic medical institution from April 2020 through June 2020. Survey questions evaluated feedback methods for six domains: preparedness, performance, attitude, technical procedures, inpatient, and outpatient care. Participants selected a preferred feedback method for each category. Patient demographics and survey responses were described using frequency statistics. We compared differences in feedback preferences based on generation and field of practice. RESULTS: A total of 871 participants completed the survey. Preferred feedback patterns in the medical field do not seem to align with sociologic theories of generational gaps. Most participants preferred to receive direct feedback after an activity away from their team, irrespective of their age or medical specialty. Individuals preferred direct feedback during an activity in front of their team only for technical procedures. Compared to nonsurgeons, surgeons were more likely to prefer direct feedback in front of team members for preparedness, performance, and attitude. CONCLUSIONS: Generational membership is not significantly associated with preferred feedback patterns in this complex medical academic environment. Variations in feedback preferences are associated with field of practice that may be due to specialty-specific differences in culture and personality traits present within certain medical specialties, particularly surgery.

Sociodemographic and Clinical Predictors of Neoadjuvant Chemotherapy in cT1-T2/N0 HER2-Amplified Breast Cancer.

BACKGROUND: The optimal treatment strategy for small node-negative human epidermal growth factor receptor 2-positive (HER2+) breast cancer remains controversial. Neoadjuvant chemotherapy may risk overtreatment, whereas surgery first fails to identify patients with residual disease in need of escalated adjuvant systemic therapy. We investigated patient characteristics associated with receipt of neoadjuvant chemotherapy. METHODS: Adult women with cT1-T2/N0, HER2+ breast cancer between 2013 and 2017 in the National Cancer Database who underwent surgery within 8 months of diagnosis were included. Patients were classified as receiving neoadjuvant chemotherapy versus a surgery-first approach. We assessed the sociodemographic and clinical predictors of neoadjuvant chemotherapy versus surgery first and associations between neoadjuvant chemotherapy and breast cancer treatments using multivariable regression models. RESULTS: We identified 56,784 women, of whom 12,758 (22%) received neoadjuvant chemotherapy, 29,139 (53%) received adjuvant chemotherapy, 12,907 (24%) received no chemotherapy, and 1980 were missing chemotherapy information. After adjustment, cT2 stage was the strongest predictor of neoadjuvant chemotherapy compared with surgery first. Younger age and later diagnosis year were positively associated with receipt of neoadjuvant chemotherapy. In contrast, hormone receptor positivity, Black race, rural county, and government-funded or no health insurance were inversely associated with neoadjuvant chemotherapy. In multivariable analyses, patients who received neoadjuvant chemotherapy were more likely to have a mastectomy (vs. lumpectomy) and sentinel lymph node biopsy or no nodal surgery (vs. axillary lymph node dissection). Patients who received neoadjuvant chemotherapy were more likely to receive multi-agent (vs. single-agent) chemotherapy than those who received adjuvant chemotherapy. CONCLUSIONS: Substantial differences in the utilization of neoadjuvant chemotherapy exist in women with HER2+ breast cancer, which reflect both clinical parameters and disparities. Optimal treatment strategies should be implemented equitably across sociodemographic groups.

Trends in the use of disease-modifying therapies among reproductive-aged women with multiple sclerosis in the United States from 2010 to 2019.

PURPOSE: Multiple sclerosis (MS) is a chronic disease of the central nervous system that disproportionately affects women, with typical onset during reproductive age. Several disease-modifying therapies (DMTs) are FDA-approved to slow disease progression, but are not indicated for use during pregnancy. Our objective was to describe trends over time (2010-2019) in monthly point prevalence of DMT use among reproductive-age women, overall and by generic name. METHODS: This study used administrative claims data from the US during 2009-2019 to identify women age 15-44 with MS and continuous insurance coverage for ≥12 months. DMTs were identified using prescription fills and procedural claims for alemtuzumab, daclizumab, dimethyl fumarate, fingolimod, glatiramer acetate, interferon beta, mitoxantrone, natalizumab, ocrelizumab, and teriflunomide. Monthly prevalent use was defined as ≥1 days' supply of a DMT in the month. Age- and region-standardized monthly prevalence was estimated nonparametrically. RESULTS: Among 42 281 reproductive-aged women over 818 179 person-months, DMT use increased from a minimum monthly prevalence of 49.3% (February, 2011) to a maximum of 58.7% (April, 2019). In 2010, prevalence of injectable DMTs was 43.1% compared to 2.5% for oral DMTs; by 2014, however, oral DMTs (26.5%) surpassed injectable DMTs (23.7%) as the most common route of administration. In the most recent data available (December, 2019), the most common DMTs were dimethyl fumarate, glatiramer acetate, and fingolimod. CONCLUSIONS: DMT use among reproductive-aged women has rapidly evolved during the past decade. Collaborative treatment decision making between women with MS and clinicians may help optimize MS care and improve DMT uptake during reproductive years.

Minimally invasive, benign foregut surgery is not associated with long-term, persistent opioid use postoperatively: an analysis of the IBM® MarketScan® database.

BACKGROUND: It is unknown if opioid naïve patients who undergo minimally invasive, benign foregut operations are at risk for progressing to persistent postoperative opioid use. The purpose of our study was to determine if opioid naïve patients who undergo minimally invasive, benign foregut operations progress to persistent postoperative opioid use and to identify any patient- and surgery-specific factors associated with persistent postoperative opioid use. METHODS: Opioid-naïve, adult patients who underwent laparoscopic fundoplication, hiatal hernia repair, or Heller myotomy from 2010 to 2018 were identified within the IBM® MarketScan® Commercial Claims and Encounters Database. Daily drug logs of the preoperative and postoperative period were evaluated to assess for changes in drug use patters. The primary outcome of interest was persistent postoperative opioid use, defined as at least 33% of the proportion of days covered by opioid prescriptions at 365-day follow-up. Patient demographic information and clinical risk factors for persistent postoperative opioid use at 365 days postoperatively were estimated using log-binomial regression. RESULTS: A total of 17,530 patients met inclusion criteria; 6895 underwent fundoplication, 9235 underwent hiatal hernia repair, and 1400 underwent Heller myotomy. 9652 patients had at least one opioid prescription filled in the perioperative period. Sixty-five patients (0.4%) were found to have persistent postoperative opioid use at 365 days postoperatively. Lower Charlson comorbidity index scores and a history of mental illness or substance use disorder had a statistically but not clinically significant protective effect on the risk of persistent postoperative opioid use at 365 days postoperatively. CONCLUSIONS: Only half of opioid naïve patients undergoing minimally invasive, benign foregut operations filled an opioid prescription postoperatively. The risk of progression to persistent postoperative opioid use was less than 1%. These findings support the current guidelines that limit the number of opioid pills prescribed following general surgery operations.

Family-based cognitive behavioural therapy versus family-based relaxation therapy for obsessive-compulsive disorder in children and adolescents: protocol for a randomised clinical trial (the TECTO trial).

BACKGROUND: Cognitive behavioural therapy (CBT) is the recommended first-line treatment for children and adolescents with obsessive-compulsive disorder (OCD), but evidence concerning treatment-specific benefits and harms compared with other interventions is limited. Furthermore, high risk-of-bias in most trials prevent firm conclusions regarding the efficacy of CBT. We investigate the benefits and harms of family-based CBT (FCBT) versus family-based psychoeducation and relaxation training (FPRT) in youth with OCD in a trial designed to reduce risk-of-bias. METHODS: This is an investigator-initiated, independently funded, single-centre, parallel group superiority randomised clinical trial (RCT). Outcome assessors, data managers, statisticians, and conclusion drawers are blinded. From child and adolescent mental health services we include patients aged 8-17 years with a primary OCD diagnosis and an entry score of ≥16 on the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). We exclude patients with comorbid illness contraindicating trial participation; intelligence quotient < 70; or treatment with CBT, PRT, antidepressant or antipsychotic medication within the last 6 months prior to trial entry. Participants are randomised 1:1 to the experimental intervention (FCBT) versus the control intervention (FPRT) each consisting of 14 75-min sessions. All therapists deliver both interventions. Follow-up assessments occur in week 4, 8 and 16 (end-of-treatment). The primary outcome is OCD symptom severity assessed with CY-BOCS at end-of-trial. Secondary outcomes are quality-of-life and adverse events. Based on sample size estimation, a minimum of 128 participants (64 in each intervention group) are included. DISCUSSION: In our trial design we aim to reduce risk-of-bias, enhance generalisability, and broaden the outcome measures by: 1) conducting an investigator-initiated, independently funded RCT; 2) blinding investigators; 3) investigating a representative sample of OCD patients; 3) using an active control intervention (FPRT) to tease apart general and specific therapy effects; 4) using equal dosing of interventions and therapist supervision in both intervention groups; 5) having therapists perform both interventions decided by randomisation; 6) rating fidelity of both interventions; 7) assessing a broad range of benefits and harms with repeated measures. The primary study limitations are the risk of missing data and the inability to blind participants and therapists to the intervention. TRIAL REGISTRATION: ClinicalTrials.gov : NCT03595098, registered July 23, 2018.

Gender Disparities in Aortoiliac Revascularization in Patients with Aortoiliac Occlusive Disease.

BACKGROUND: Gender disparities have been previously reported in aortic aneurysm and critical limb ischemia outcomes; however, limited info is known about disparities in aortoiliac occlusive disease. We sought to characterize potential disparities in this specific population. MATERIAL AND METHODS: Patients who underwent aortobifemoral bypass and aortic thromboendarterectomy (Current Procedural Terminology codes 35646 and 35331) between 2012 and 2019 were identified in the National Surgical Quality Improvement Program database. A binomial regression model was used to estimate gender differences in 30-day morbidity and mortality. Inverse probability weighting was used to standardize demographic and surgical characteristics. RESULTS: We identified 1,869 patients, of which 39.8% were female and the median age was 61 years. Age, body composition, and other baseline characteristics were overall similar between genders; however, racial data were missing for 26.1% of patients. Females had a higher prevalence of preexisting chronic obstructive pulmonary disease (20.9% vs. 14.7%, prevalence difference 6.1%, P < 0.01), diabetes mellitus (25.4% vs. 19.4%, prevalence difference 6.0%, P < 0.01), and high-risk anatomical features (39.4% vs. 33.7%, prevalence difference 5.8%, P = 0.01). Preprocedural medications included a statin in only 68.2% of patients and antiplatelet agent in 76.7% of patients. Females also had a higher incidence of bleeding events when compared to males (25.2% vs. 17.5%, standardized risk difference 7.2%, P < 0.01), but were less likely to have a prolonged hospitalization greater than 10 days (18.2% vs. 20.9%, standardized risk difference -5.0%, P = 0.01). The 30-day mortality rate was not significantly different between genders (4.7% vs. 3.6%, standardized risk difference 1.2%, P = 0.25). CONCLUSIONS: Female patients treated with aortobifemoral bypass or aortic thromboendarterectomy are more likely to have preexisting chronic obstructive pulmonary disease, diabetes mellitus, and high-risk anatomical features. Regardless of a patient's gender, there is poor adherence to preoperative medical optimization with both statins and antiplatelet agents. Female patients are more likely to have postoperative bleeding complications while males are more likely to have a prolonged hospital stay greater than 10 days. Future work could attempt to further delineate disparities using databases with longer follow-up data and seek to create protocols for reducing these observed disparities.

Correction: KAT6A Syndrome: genotype-phenotype correlation in 76 patients with pathogenic KAT6A variants.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

GATAD2B-associated neurodevelopmental disorder (GAND): clinical and molecular insights into a NuRD-related disorder.

PURPOSE: Determination of genotypic/phenotypic features of GATAD2B-associated neurodevelopmental disorder (GAND). METHODS: Fifty GAND subjects were evaluated to determine consistent genotypic/phenotypic features. Immunoprecipitation assays utilizing in vitro transcription-translation products were used to evaluate GATAD2B missense variants' ability to interact with binding partners within the nucleosome remodeling and deacetylase (NuRD) complex. RESULTS: Subjects had clinical findings that included macrocephaly, hypotonia, intellectual disability, neonatal feeding issues, polyhydramnios, apraxia of speech, epilepsy, and bicuspid aortic valves. Forty-one novelGATAD2B variants were identified with multiple variant types (nonsense, truncating frameshift, splice-site variants, deletions, and missense). Seven subjects were identified with missense variants that localized within two conserved region domains (CR1 or CR2) of the GATAD2B protein. Immunoprecipitation assays revealed several of these missense variants disrupted GATAD2B interactions with its NuRD complex binding partners. CONCLUSIONS: A consistent GAND phenotype was caused by a range of genetic variants in GATAD2B that include loss-of-function and missense subtypes. Missense variants were present in conserved region domains that disrupted assembly of NuRD complex proteins. GAND's clinical phenotype had substantial clinical overlap with other disorders associated with the NuRD complex that involve CHD3 and CHD4, with clinical features of hypotonia, intellectual disability, cardiac defects, childhood apraxia of speech, and macrocephaly.

Diagnostic utility of transcriptome sequencing for rare Mendelian diseases.

PURPOSE: We investigated the value of transcriptome sequencing (RNAseq) in ascertaining the consequence of DNA variants on RNA transcripts to improve the diagnostic rate from exome or genome sequencing for undiagnosed Mendelian diseases spanning a wide spectrum of clinical indications. METHODS: From 234 subjects referred to the Undiagnosed Diseases Network, University of California-Los Angeles clinical site between July 2014 and August 2018, 113 were enrolled for high likelihood of having rare undiagnosed, suspected genetic conditions despite thorough prior clinical evaluation. Exome or genome sequencing and RNAseq were performed, and RNAseq data was integrated with genome sequencing data for DNA variant interpretation genome-wide. RESULTS: The molecular diagnostic rate by exome or genome sequencing was 31%. Integration of RNAseq with genome sequencing resulted in an additional seven cases with clear diagnosis of a known genetic disease. Thus, the overall molecular diagnostic rate was 38%, and 18% of all genetic diagnoses returned required RNAseq to determine variant causality. CONCLUSION: In this rare disease cohort with a wide spectrum of undiagnosed, suspected genetic conditions, RNAseq analysis increased the molecular diagnostic rate above that possible with genome sequencing analysis alone even without availability of the most appropriate tissue type to assess.

Correction: GATAD2B-associated neurodevelopmental disorder (GAND): clinical and molecular insights into a NuRD-related disorder.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A well-tolerated core needle muscle biopsy process suitable for children and adults.

Serial muscle biopsies within clinical trials for Duchenne muscular dystrophy (DMD) are critical to document therapeutic responses. Less invasive means of sampling muscle are needed. We analyzed a retrospective consecutive case-series cohort of vacuum-assisted core needle muscle biopsy procedures performed on healthy and dystrophic individuals at a single institution assessing for safety and reliability of obtaining sufficient high-quality biopsy tissue for histologic assessment in adult and pediatric subjects. Of 471 muscle cores from 128 biopsy procedures, 377-550 mg of total muscle tissue was obtained per procedure with mean core weight of 129 mg (SD, 25.1 mg). All biopsies were adequate for histological assessment. There were no significant adverse events. This core needle biopsy approach, when combined with improved sample processing, provides a safe means to consistently obtain muscle samples for diagnostic and clinical trial applications.

Metaxa2 Database Builder: enabling taxonomic identification from metagenomic or metabarcoding data using any genetic marker.

Motivation: Correct taxonomic identification of DNA sequences is central to studies of biodiversity using both shotgun metagenomic and metabarcoding approaches. However, no genetic marker gives sufficient performance across all the biological kingdoms, hampering studies of taxonomic diversity in many groups of organisms. This has led to the adoption of a range of genetic markers for DNA metabarcoding. While many taxonomic classification software tools can be re-trained on these genetic markers, they are often designed with assumptions that impair their utility on genes other than the SSU and LSU rRNA. Here, we present an update to Metaxa2 that enables the use of any genetic marker for taxonomic classification of metagenome and amplicon sequence data. Results: We evaluated the Metaxa2 Database Builder on 11 commonly used barcoding regions and found that while there are wide differences in performance between different genetic markers, our software performs satisfactorily provided that the input taxonomy and sequence data are of high quality. Availability and implementation: Freely available on the web as part of the Metaxa2 package at http://microbiology.se/software/metaxa2/. Supplementary information: Supplementary data are available at Bioinformatics online.

KAT6A Syndrome: genotype-phenotype correlation in 76 patients with pathogenic KAT6A variants.

PURPOSE: Pathogenic variants in KAT6A have recently been identified as a cause of syndromic developmental delay. Within 2 years, the number of patients identified with pathogenic KAT6A variants has rapidly expanded and the full extent and variability of the clinical phenotype has not been reported. METHODS: We obtained data for patients with KAT6A pathogenic variants through three sources: treating clinicians, an online family survey distributed through social media, and a literature review. RESULTS: We identified 52 unreported cases, bringing the total number of published cases to 76. Our results expand the genotypic spectrum of pathogenic variants to include missense and splicing mutations. We functionally validated a pathogenic splice-site variant and identified a likely hotspot location for de novo missense variants. The majority of clinical features in KAT6A syndrome have highly variable penetrance. For core features such as intellectual disability, speech delay, microcephaly, cardiac anomalies, and gastrointestinal complications, genotype- phenotype correlations show that late-truncating pathogenic variants (exons 16-17) are significantly more prevalent. We highlight novel associations, including an increased risk of gastrointestinal obstruction. CONCLUSION: Our data expand the genotypic and phenotypic spectrum for individuals with genetic pathogenic variants in KAT6A and we outline appropriate clinical management.

Prediction and Comparison of Fentanyl Infusion Pharmacokinetics in Obese and Nonobese Children.

OBJECTIVES: To compare fentanyl infusion pharmacokinetic variables in obese children and nonobese children. DESIGN: A pharmacokinetic simulation study. SETTING: We used a semi-physiologically based pharmacokinetic model to generate fentanyl pharmacokinetic variables. SUBJECTS: Simulations of pharmacokinetic variables were based on historical inpatient demographic data in less than 18-year-olds. INTERVENTIONS: Obese children were defined as children less than 2 years with weight-for-length greater than or equal to 97.7th percentile or body mass index-for-age greater than or equal to 95th percentile for greater than or equal to 2-17-year-olds. MEASUREMENTS AND MAIN RESULTS: Overall, 4,376 patients were included, with 807 (18.4%) classified as obese children. The majority (52.9%) were male, with a median age of 8.1 years (interquartile range, 4.3-13.0 yr). The differences in total clearance (CLS), volume of distribution at steady-state values, weight-normalized CLS, and weight-normalized volume of distribution at steady state were assessed in obese children and nonobese children. Multivariable analyses indicated that obesity was significantly associated with a higher CLS in obese children greater than 6-year-olds (p < 0.0375). However, there was an 11-30% decrease in weight-normalized CLS in obese children versus nonobese children in all age groups (p < 0.05). Both volume of distribution at steady state and weight-normalized volume of distribution at steady state increased significantly in obese children compared with nonobese children (p < 0.05). Fentanyl plasma concentration-time profiles of obese children and nonobese children pairs (ages 4, 9, and 15) receiving 1 µg/kg/hr using total body weight were also compared. Steady-state concentrations of the obese children using similar weight-based dosing increased by 25%, 77%, and 44% in comparison to nonobese children 4-, 9-, and 15-year-olds, respectively. Time to steady state and elimination half-lives were two- to four-fold longer in obese children. An additional simulation was conducted for 15-year-old obese children and nonobese children using a fixed dose of 50 µg/hr and it provided similar pharmacokinetic profiles. CONCLUSIONS: CLS may increase less than proportional to weight in obese children greater than 6-year-olds, while volume of distribution at steady state increases more than proportional to weight in all obese children compared with nonobese children. Weight-based dosing in obese children may cause an increase in steady-state concentration while prolonging the time to steady state. Exploring alternative dosing strategies for obese children is warranted.