A novel variant in ADPRS disrupts ARH3 stability and subcellular localization in children with neurodegeneration and respiratory failure.

Purpose: ADP-ribosylation is a post-translational modification involving the transfer of one or more ADP-ribose units from NAD+ to target proteins. Dysregulation of ADP-ribosylation is implicated in neurodegenerative diseases. Here we report a novel homozygous variant in the ADPRS gene (c.545A>G, p.His182Arg) encoding the mono(ADP-ribosyl) hydrolase ARH3 found in 2 patients with childhood-onset neurodegeneration with stress-induced ataxia and seizures (CONDSIAS). Methods: Genetic testing via exome sequencing was used to identify the underlying disease cause in two siblings with developmental delay, seizures, progressive muscle weakness, and respiratory failure following an episodic course. Studies in a cell culture model uncover biochemical and cellular consequences of the identified genetic change. Results: The ARH3 H182R variant affects a highly conserved residue in the active site of ARH3, leading to protein instability, degradation, and reduced expression. ARH3 H182R additionally fails to localize to the nucleus. The combination of reduced expression and mislocalization of ARH3 H182R resulted in accumulation of mono-ADP ribosylated species in cells. Conclusions: The children's clinical course combined with the biochemical characterization of their genetic variant develops our understanding of the pathogenic mechanisms driving CONDSIAS and highlights a critical role for ARH3-regulated ADP ribosylation in nervous system integrity.

Newer Pharmacologic Treatments in Adults With Type 2 Diabetes: A Systematic Review and Network Meta-analysis for the American College of Physicians.

BACKGROUND: Newer diabetes medications may have beneficial effects on mortality, cardiovascular outcomes, and renal outcomes. PURPOSE: To evaluate the effectiveness, comparative effectiveness, and harms of sodium-glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP1) agonists, dipeptidyl peptidase-4 (DPP4) inhibitors, and long-acting insulins as monotherapy or combination therapy in adults with type 2 diabetes mellitus (T2DM). DATA SOURCES: MEDLINE and EMBASE for randomized controlled trials (RCTs) published from 2010 through January 2023. STUDY SELECTION: RCTs lasting at least 52 weeks that included at least 500 adults with T2DM receiving eligible medications and reported any outcomes of interest. DATA EXTRACTION: Data were abstracted by 1 reviewer and verified by a second. Independent, dual assessments of risk of bias and certainty of evidence (CoE) were done. DATA SYNTHESIS: A total of 130 publications from 84 RCTs were identified. CoE was appraised using GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria for direct, indirect, and network meta-analysis (NMA); the highest CoE was reported. Compared with usual care, SGLT2 inhibitors and GLP1 agonists reduce all-cause mortality (high CoE) and major adverse cardiovascular events (MACE) (moderate to high CoE), SGLT2 inhibitors reduce progression of chronic kidney disease (CKD) and heart failure hospitalizations and GLP1 agonists reduce stroke (high CoE), and SGLT2 inhibitors reduce serious adverse events and severe hypoglycemia (high CoE). The threshold for minimally important differences, which was predefined with the American College of Physicians Clinical Guidelines Committee, was not met for these outcomes. Compared with usual care, insulin, tirzepatide, and DPP4 inhibitors do not reduce all-cause mortality (low to high CoE). Compared with insulin, SGLT2 inhibitors and GLP1 agonists reduce all-cause mortality (low to moderate CoE). Compared with DPP4 inhibitors, GLP1 agonists reduce all-cause mortality (moderate CoE). Compared with DPP4 inhibitors and sulfonylurea (SU), SGLT2 inhibitors reduce MACE (moderate to high CoE). Compared with SU and insulin, SGLT2 inhibitors and GLP1 agonists reduce severe hypoglycemia (low to high CoE). LIMITATIONS: Infrequent direct comparisons between drugs of interest; sparse data for NMA on most outcomes; possible incoherence due to differences in baseline patient characteristics and usual care; insufficient data on predefined subgroups, including demographic subgroups, patients with prior cardiovascular disease, and treatment-naive persons. CONCLUSION: In adults with T2DM, SGLT2 inhibitors and GLP1 agonists (but not DPP4 inhibitors, insulin, or tirzepatide) reduce all-cause mortality and MACE compared with usual care. SGLT2 inhibitors reduce CKD progression and heart failure hospitalization and GLP1 agonists reduce stroke compared with usual care. Serious adverse events and severe hypoglycemia are less frequent with SGLT2 inhibitors and GLP1 agonists than with insulin or SU. PRIMARY FUNDING SOURCE: American College of Physicians. (PROSPERO: CRD42022322129).

Cost-Effectiveness of Newer Pharmacologic Treatments in Adults With Type 2 Diabetes: A Systematic Review of Cost-Effectiveness Studies for the American College of Physicians.

BACKGROUND: In the United States, costs of antidiabetes medications exceed $327 billion. PURPOSE: To systematically review cost-effectiveness analyses (CEAs) of newer antidiabetes medications for type 2 diabetes. DATA SOURCES: Bibliographic databases from 1 January 2010 through 13 July 2023, limited to English. STUDY SELECTION: Nonindustry-funded CEAs, done from a U.S. perspective that estimated cost per quality-adjusted life-year (QALY) gained for newer antidiabetic medications. Two reviewers screened the literature; disagreements were resolved with a third reviewer. DATA EXTRACTION: Cost-effectiveness analyses were reviewed for treatment comparisons, model inputs, and outcomes. Risk of bias (RoB) of the CEAs was assessed using Drummond criteria and certainty of evidence (CoE) was assessed using GRADE (Grading of Recommendations Assessment, Development, and Evaluations). Certainty of evidence was determined using cost per QALY thresholds predetermined by the American College of Physicians Clinical Guidelines Committee; low (>$150 000), intermediate ($50 to $150 000), or high (<$50 000) value per QALY compared with the alternative. DATA SYNTHESIS: Nine CEAs were eligible (2 low, 1 high, and 6 some concerns RoB), evaluating glucagon-like peptide-1 agonists (GLP1a), dipeptidyl peptidase-4 inhibitors (DPP4i), sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucose-dependent insulinotropic peptide agonist (GIP/GLP1a), and insulin. Comparators were metformin, sulfonylureas, neutral protamine Hagedorn (NPH) insulin, and others. Compared with metformin, GLP1a and SGLT2i are low value as first-line therapy (high CoE) but may be of intermediate value when added to metformin or background therapy compared with adding nothing (low CoE). Insulin analogues may be similarly effective but more expensive than NPH insulin (low CoE). The GIP/GLP1a value is uncertain (insufficient CoE). LIMITATIONS: Cost-effectiveness analyses varied in methodological approach, assumptions, and drug comparisons. Risk of bias and GRADE method for CEAs are not well established. CONCLUSION: Glucagon-like peptide-1 agonists and SGLT2i are of low value as first-line therapy but may be of intermediate value when added to metformin or other background therapy compared with adding nothing. Other drugs and comparisons are of low or uncertain value. Results are sensitive to drug effectiveness and cost assumptions. PRIMARY FUNDING SOURCE: American College of Physicians. (PROSPERO: CRD42022382315).

Matrisome and Immune Pathways Contribute to Extreme Vascular Outcomes in Williams-Beuren Syndrome.

BACKGROUND: Supravalvar aortic stenosis (SVAS) is a characteristic feature of Williams-Beuren syndrome (WBS). Its severity varies: ~20% of people with Williams-Beuren syndrome have SVAS requiring surgical intervention, whereas ~35% have no appreciable SVAS. The remaining individuals have SVAS of intermediate severity. Little is known about genetic modifiers that contribute to this variability. METHODS AND RESULTS: We performed genome sequencing on 473 individuals with Williams-Beuren syndrome and developed strategies for modifier discovery in this rare disease population. Approaches include extreme phenotyping and nonsynonymous variant prioritization, followed by gene set enrichment and pathway-level association tests. We next used GTEx v8 and proteomic data sets to verify expression of candidate modifiers in relevant tissues. Finally, we evaluated overlap between the genes/pathways identified here and those ascertained through larger aortic disease/trait genome-wide association studies. We show that SVAS severity in Williams-Beuren syndrome is associated with increased frequency of common and rarer variants in matrisome and immune pathways. Two implicated matrisome genes (ACAN and LTBP4) were uniquely expressed in the aorta. Many genes in the identified pathways were previously reported in genome-wide association studies for aneurysm, bicuspid aortic valve, or aortic size. CONCLUSIONS: Smaller sample sizes in rare disease studies necessitate new approaches to detect modifiers. Our strategies identified variation in matrisome and immune pathways that are associated with SVAS severity. These findings suggest that, like other aortopathies, SVAS may be influenced by the balance of synthesis and degradation of matrisome proteins. Leveraging multiomic data and results from larger aorta-focused genome-wide association studies may accelerate modifier discovery for rare aortopathies like SVAS.

Telephone Virtual Versus In-Person Pharmacotherapy-Based Obesity Care: A COVID-19-Related Experience at a Veterans Administration Facility.

Background: Most of the Veterans Administration (VA) population is either overweight or obese, which is a serious health concern. Medical weight management visits have traditionally occurred through in-person clinics. However, the COVID-19 pandemic forced care delivery to virtual platforms. Methods: We compared weight loss with in-person versus telephone-based medical weight management (lifestyle counseling coupled with pharmacotherapy) delivered by physician and nurse practitioner visits during the pandemic. We designed a program evaluation utilizing a naturalistic (pragmatic) observational study structure, including both newly enrolled and previously established participants in the Minneapolis VA MOVE! program between 2017 and 2021. A "transition" cohort (n = 74) received in-person care from March 2019 to March 2020, and then transitioned to virtual care. A "new start" virtual care cohort (n = 149) enrolled after March 2020 was compared to a separate historical group (n = 180) that received in-person care between January 2017 and December 2019. Weight loss was accessed over a 9-month period in both cohorts. Results: Mean weight loss over 9 months was -6.5 ± 18.2 and -2.5 ± 13.3 lbs in the in-person and virtual phases of the transition cohort, respectively, without significant difference between the two phases (p = 0.22). Mean weight loss over 9 months in the new start (virtual) cohort was -14.4 ± 17.0 lbs compared to -16.7 ± 21.0 lbs in the historical cohort, without significant difference between groups (p = 0.44). Conclusions: In our naturalistic study in a single-site VA clinic setting, weight loss with telephone-based medical weight management during the pandemic was comparable to in-person care. These findings are important for veterans living in rural and/or underserved areas.

Combining Celiac and Hepatic Vagus Nerve Neuromodulation Reverses Glucose Intolerance and Improves Glycemic Control in Pre- and Overt-Type 2 Diabetes Mellitus.

Neurological disorders and type 2 diabetes mellitus (T2DM) are deeply intertwined. For example, autonomic neuropathy contributes to the development of T2DM and continued unmanaged T2DM causes further progression of nerve damage. Increasing glycemic control has been shown to prevent the onset and progression of diabetic autonomic neuropathies. Neuromodulation consisting of combined stimulation of celiac vagal fibers innervating the pancreas with concurrent electrical blockade of neuronal hepatic vagal fibers innervating the liver has been shown to increase glycemic control in animal models of T2DM. The present study demonstrated that the neuromodulation reversed glucose intolerance in alloxan-treated swine in both pre- and overt stages of T2DM. This was demonstrated by improved performance on oral glucose tolerance tests (OGTTs), as assessed by area under the curve (AUC). In prediabetic swine (fasting plasma glucose (FPG) range: 101-119 mg/dL) the median AUC decreased from 31.9 AUs (IQR = 28.6, 35.5) to 15.9 AUs (IQR = 15.1, 18.3) p = 0.004. In diabetic swine (FPG range: 133-207 mg/dL) the median AUC decreased from 54.2 AUs (IQR = 41.5, 56.6) to 16.0 AUs (IQR = 15.4, 21.5) p = 0.003. This neuromodulation technique may offer a new treatment for T2DM and reverse glycemic dysregulation at multiple states of T2DM involved in diabetic neuropathy including at its development and during progression.

Use of a bio-electronic device comprising of targeted dual neuromodulation of the hepatic and celiac vagal branches demonstrated enhanced glycemic control in a type 2 diabetic rat model as well as in an Alloxan treated swine model.

Background: There is an unmet need for new type 2 diabetes treatments providing improved efficacy, durability and customized to improve patient's compliance. Bio-electronic neuromodulation of Vagus nerve branches innervating organs that regulate plasma glucose, may be a method for treating type 2 diabetes. The pancreas has been shown to release insulin during Vagus stimulation. The hepatic vagal branch, innervating the liver, has been shown to decrease glucose release and decrease insulin resistance following ligation. However, standalone stimulation of the Vagus nerve has shown mixed results and Vagus nerve ligation has undesirable effects. Little is known; however, of the effect on plasma glucose with combined neuromodulation consisting of stimulation of the celiac branch innervating the pancreas with simultaneous high frequency alternating current (HFAC) blockade of the hepatic branch. This study tested the effects of this approach on increasing glycemic control in rat a model of type 2 diabetes and Alloxan treated swine. Materials and methods: Zucker obese (fatty) male rats (ZDF fa/fa) were used as a model of type 2 diabetes as well as glucose intolerant Alloxan treated swine. In ZDF rat experiments glycemic control was accessed with an intravenous glucose tolerance test during HFAC-induced hepatic branch block with concurrent celiac stimulation (HFAC + stimulation). In swine experiments glycemic control was accessed by an oral glucose tolerance test during HFAC + stimulation. Insulin measurements were taken prior to and following swine experiments giving insight into beta cell exhaustion. Histopathology was conducted to determine safety of HFAC + stimulation on Vagal branches. Results: Zucker rats demonstrated a significant improvement to an intravenous glucose tolerance test during HFAC + stimulation compared to sham. There was no significant difference from sham compared to hepatic vagotomy or celiac stimulation. In Alloxan treated swine, when subjected to HFAC + stimulation, there was a significant improvement in glycemic control as measured by an improvement on oral glucose tolerance tests and a decrease in fasting plasma glucose. Insulin responses were similar prior to and following HFAC + stimulation experiments. Histopathology demonstrated healthy swine Vagus nerves. Conclusion: Electrical blockade of the hepatic Vagus branch with simultaneous stimulation of the celiac Vagus branch may be a novel, adjustable and localized approach for a treatment of type 2 diabetes.

Reporting of Incidental Thyroid Nodules on Chest Computed Tomography and the Impact on Nodule Evaluation: A Retrospective Cohort Study.

Introduction: Thyroid incidentalomas are frequently identified thyroid nodules viewed on nonthyroid dedicated imaging studies. Clinical guidelines recommend evaluation of all thyroid incidentalomas to risk stratify for cancer. This study examined how thyroid incidentalomas are reported on chest computed tomography (CT) and determined the association of reporting location with likelihood of evaluation and risk of long-term outcomes. Methods: Retrospective cohort of 1460 previously identified Veterans with thyroid incidentalomas on chest CT from a single VA institution between 1995 and 2016. Reporting of the incidentaloma was categorized as either in the body of the report alone or in the impression. Demographic data, vital status, thyroid ultrasound, endocrinology consult, thyroid nodule fine needle aspiration, thyroid surgery, thyroid cancer diagnosis, and death from thyroid cancer were abstracted. Results: Among the 1460 Veterans (mean age 70.4 years and 94.9% male) in the cohort, 707 incidentalomas (48.4%) were reported in the impression and 753 (51.6%) were reported in the body section. Veterans with thyroid incidentalomas reported in the impression versus body were significantly more likely to be evaluated within 6 months (35.5% vs. 5.1%; p ≤ 0.001), 12 months (38.5% vs. 6.5%; p ≤ 0.001), and at any time during the follow-up period (47.8% vs. 13.2%; p ≤ 0.001). Veterans with thyroid incidentalomas reported in the impression versus body were more likely to undergo thyroidectomy (18 [2.6%] vs. 6 [0.8%]; p = 0.009), but there was no difference in the proportion of Veterans diagnosed with thyroid cancer (11 [1.6%] vs. 6 [0.8%]; p = 0.18), thyroid-cancer related mortality (4 [0.6%] vs. 1 [0.1%]; p = 0.16), or all-cause mortality (63.2% vs. 66.5%; p = 0.19). Conclusions: Thyroid incidentalomas on chest CT are inconsistently reported and often receive no subsequent evaluation. The location of reporting affects whether clinical evaluation is performed, yet reporting does not affect the proportion of Veterans who died of any cause and may have little effect on the proportion of Veterans who received a diagnosis of thyroid cancer or died from thyroid cancer. These findings suggest that the guideline recommendation to evaluate all thyroid incidentalomas should be reevaluated.

COVID-19 postacute care major organ damage: a systematic review.

BACKGROUND: Major organ complications have been reported in patients hospitalised for COVID-19; most studies lacked controls. OBJECTIVE: Examine major organ damage postdischarge among adults hospitalised for COVID-19 versus non-COVID-19 controls. DATA SOURCES: MEDLINE, Embase and Cochrane Library from 1 January 2020 to 19 May 2021. STUDY ELIGIBILITY CRITERIA: English language studies of adults discharged from hospital for COVID-19; reporting major organ damage. Single review of abstracts; independent dual review of full text. STUDY APPRAISAL AND SYNTHESIS METHODS: Study quality was assessed using the Joanna Briggs Institute Appraisal Checklist for Cohort Studies. Outcome data were not pooled due to heterogeneity in populations, study designs and outcome assessment methods; findings are narratively synthesised. RESULTS: Of 124 studies in a full evidence report, 9 included non-COVID controls and are described here. Four of the nine (three USA, one UK) used large administrative databases. Four of the remaining five studies enrolled <600 COVID-19 patients. Mean or median age ranged from 49 to 70 years with 46%-94% male and 48%-78% White race; 10%-40% had been in intensive care units. Follow-up ranged from 4 weeks to 22 weeks postdischarge. Four used hospitalised controls, three non-hospitalised controls and two were unclear. Studies used various definitions of, and methods to assess, major organ damage outcomes. While the magnitude of effect differed across studies, incident cardiac, pulmonary, liver, acute and chronic kidney, stroke, diabetes, and coagulation disorders were consistently greater in adults hospitalised for COVID-19 compared with non-COVID-19 controls. LIMITATIONS: Applicability to subgroups (age, gender, COVID-19 severity, treatment, vaccination status) and non-hospitalised patients is unknown. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Postacute COVID-19 major organ damage is common and likely higher than controls. However, there is substantial uncertainty. More consistent reporting of clinical outcomes and pre-COVID health status along with careful selection of control groups are needed to address evidence gaps. PROSPERO REGISTRATION NUMBER: CRD42020204788.

Genomic and biochemical analysis of repeatedly observed variants in DBT in individuals with maple syrup urine disease of Central American ancestry.

Maple syrup urine disease (MSUD) is an intoxication-type inherited metabolic disorder in which hyperleucinemia leads to brain swelling and death without treatment. MSUD is caused by branched-chain alpha-ketoacid dehydrogenase deficiency due to biallelic loss of the protein products from the genes BCKDHA, BCKDHB, or DBT, while a distinct but related condition is caused by loss of DLD. In this case series, eleven individuals with MSUD caused by two pathogenic variants in DBT are presented. All eleven individuals have a deletion of exon 2 (delEx2, NM_001918.3:c.48_171del); six individuals are homozygous and five individuals are compound heterozygous with a novel missense variant (NM_001918.5:c.916 T > C [p.Ser306Pro]) confirmed to be in trans. Western Blot indicates decreased amount of protein product in delEx2;c.916 T > C liver cells and absence of protein product in delEx2 homozygous hepatocytes. Ultrahigh performance liquid chromatography-tandem mass spectrometry demonstrates an accumulation of branched-chain amino acids and alpha-ketoacids in explanted hepatocytes. Individuals with these variants have a neonatal-onset, non-thiamine-responsive, classical form of MSUD. Strikingly, the entire cohort is derived from families who immigrated to the Washington, DC, metro area from Honduras or El Salvador suggesting the possibility of a founder effect.

Copper-Binding Domain Variation in a Novel Murine Lysyl Oxidase Model Produces Structurally Inferior Aortic Elastic Fibers Whose Failure Is Modified by Age, Sex, and Blood Pressure.

Lysyl oxidase (LOX) is a copper-binding enzyme that cross-links elastin and collagen. The dominant LOX variation contributes to familial thoracic aortic aneurysm. Previously reported murine Lox mutants had a mild phenotype and did not dilate without drug-induced provocation. Here, we present a new, more severe mutant, Loxb2b370.2Clo (c.G854T; p.Cys285Phe), whose mutation falls just N-terminal to the copper-binding domain. Unlike the other mutants, the C285F Lox protein was stably produced/secreted, and male C57Bl/6J Lox+/C285F mice exhibit increased systolic blood pressure (BP; p < 0.05) and reduced caliber aortas (p < 0.01 at 100mmHg) at 3 months that independently dilate by 6 months (p < 0.0001). Multimodal imaging reveals markedly irregular elastic sheets in the mutant (p = 2.8 × 10−8 for breaks by histology) that become increasingly disrupted with age (p < 0.05) and breeding into a high BP background (p = 6.8 × 10−4). Aortic dilation was amplified in males vs. females (p < 0.0001 at 100mmHg) and ameliorated by castration. The transcriptome of young Lox mutants showed alteration in dexamethasone (p = 9.83 × 10−30) and TGFß-responsive genes (p = 7.42 × 10−29), and aortas from older C57Bl/6J Lox+/C285F mice showed both enhanced susceptibility to elastase (p < 0.01 by ANOVA) and increased deposition of aggrecan (p < 0.05). These findings suggest that the secreted Lox+/C285F mutants produce dysfunctional elastic fibers that show increased susceptibility to proteolytic damage. Over time, the progressive weakening of the connective tissue, modified by sex and blood pressure, leads to worsening aortic disease.

Monoallelic and biallelic mutations in RELN underlie a graded series of neurodevelopmental disorders.

Reelin, a large extracellular protein, plays several critical roles in brain development and function. It is encoded by RELN, first identified as the gene disrupted in the reeler mouse, a classic neurological mutant exhibiting ataxia, tremors and a 'reeling' gait. In humans, biallelic variants in RELN have been associated with a recessive lissencephaly variant with cerebellar hypoplasia, which matches well with the homozygous mouse mutant that has abnormal cortical structure, small hippocampi and severe cerebellar hypoplasia. Despite the large size of the gene, only 11 individuals with RELN-related lissencephaly with cerebellar hypoplasia from six families have previously been reported. Heterozygous carriers in these families were briefly reported as unaffected, although putative loss-of-function variants are practically absent in the population (probability of loss of function intolerance = 1). Here we present data on seven individuals from four families with biallelic and 13 individuals from seven families with monoallelic (heterozygous) variants of RELN and frontotemporal or temporal-predominant lissencephaly variant. Some individuals with monoallelic variants have moderate frontotemporal lissencephaly, but with normal cerebellar structure and intellectual disability with severe behavioural dysfunction. However, one adult had abnormal MRI with normal intelligence and neurological profile. Thorough literature analysis supports a causal role for monoallelic RELN variants in four seemingly distinct phenotypes including frontotemporal lissencephaly, epilepsy, autism and probably schizophrenia. Notably, we observed a significantly higher proportion of loss-of-function variants in the biallelic compared to the monoallelic cohort, where the variant spectrum included missense and splice-site variants. We assessed the impact of two canonical splice-site variants observed as biallelic or monoallelic variants in individuals with moderately affected or normal cerebellum and demonstrated exon skipping causing in-frame loss of 46 or 52 amino acids in the central RELN domain. Previously reported functional studies demonstrated severe reduction in overall RELN secretion caused by heterozygous missense variants p.Cys539Arg and p.Arg3207Cys associated with lissencephaly suggesting a dominant-negative effect. We conclude that biallelic variants resulting in complete absence of RELN expression are associated with a consistent and severe phenotype that includes cerebellar hypoplasia. However, reduced expression of RELN remains sufficient to maintain nearly normal cerebellar structure. Monoallelic variants are associated with incomplete penetrance and variable expressivity even within the same family and may have dominant-negative effects. Reduced RELN secretion in heterozygous individuals affects only cortical structure whereas the cerebellum remains intact. Our data expand the spectrum of RELN-related neurodevelopmental disorders ranging from lethal brain malformations to adult phenotypes with normal brain imaging.

Frequency of QTc Interval Prolongation in Children and Adults with Williams Syndrome.

QTc prolongation (≥ 460 ms), according to Bazett formula (QTcB), has been identified to be increased in Williams syndrome (WS) and suggested as a potential cause of increased risk of sudden cardiac death. The Bazett formula tends to overestimate QTc in higher heart rates. We performed a retrospective chart review of WS patients with ≥ 1 electrocardiogram (EKG) with sinus rhythm, no evidence of bundle branch blocks, and measurable intervals. A total of 280 EKGs from 147 patients with WS were analyzed and 123 EKGs from 123 controls. The QTc was calculated using Bazett formula. The average QTcB for individuals with WS and controls was 444 ± 24 ms and 417 ± 26 ms, respectively (p < 0.001). In our WS cohort 34.4% had at least 1 EKG with a QTcB ≥ 460 ms. The mean heart rate (HR) from patients with WS was significantly higher than controls (96 bpm vs 76 bpm, p < 0.001). Linear regression showed that HR contributed 27% to QTcB prolongation in the patients with WS. Patients with WS have a mean QTcB in the normal range but higher than controls, and a higher than expected frequency of QTc ≥ 460 ms compared to the general population. HR is also higher in WS and contributes modestly to the WS QTcB prolongation. Future studies are needed to assess if these findings contribute risk to sudden cardiac death but in the interim we recommend routine EKG testing, especially when starting QTc prolonging medications.

Exenatide for weight-loss maintenance in adolescents with severe obesity: A randomized, placebo-controlled trial.

OBJECTIVE: This study sought to evaluate the effect of 52 weeks of exenatide extended release (XR) on the maintenance of meal replacement therapy (MRT)-induced BMI reduction in adolescents with severe obesity. METHODS: In this randomized, double-blind, placebo-controlled trial, 100 participants aged 12 to 18 years with BMI ≥ 1.2 × 95th percentile were enrolled in a short-term MRT run-in phase. Those who achieved ≥5% BMI reduction during the run-in were then randomized to 52 weeks of exenatide XR 2.0 mg or placebo weekly. Both groups also received lifestyle therapy. The prespecified primary end point was mean percent change in BMI from randomization (post run-in) to 52 weeks in the intention-to-treat population. RESULTS: A total of 100 participants were enrolled, and 66 (mean age 16 = [SD 1.5] years; 47% female) achieved ≥5% BMI reduction with MRT and were randomized (33 to exenatide XR and 33 to placebo). From randomization (post run-in) to 52 weeks, mean BMI increased 4.6% and 10.1% in the exenatide XR and placebo groups, respectively. The placebo-subtracted exenatide XR treatment effect was -4.1% (95% CI: -8.6% to 0.5%, p = 0.078). CONCLUSIONS: Although not achieving statistical significance, exenatide XR, compared with placebo, may partly mitigate the propensity toward BMI rebound in adolescents who achieved initial weight loss with dietary intervention.

A case of VEXAS syndrome associated with EBV-associated hemophagocytic lymphohistiocytosis.

Vacuoles, E1, X-linked, autoimmunity, somatic (VEXAS) syndrome is characterized by a pathogenic mutation in UBA1, which leads to protean complications including autoimmunity and myelodysplasia. A 56-year-old man with steroid-dependent, later steroid-refractory cutaneous polyarteritis nodosa and Sweet syndrome developed recurrent daily fever, macrocytic anemia, thrombocytopenia, acute hypoxic respiratory failure, and anasarca. He was eventually diagnosed with Epstein-Barr virus (EBV) viremia and hemophagocytic lymphohistiocytosis (HLH). He improved clinically with rituximab, ruxolitinib, and increased glucocorticoids before expiring from Pseudomonas sepsis. UBA1 exon 3 mutational analysis in myeloid enriched peripheral blood revealed a c.122T>C (p.Met41Thr) pathogenic variant, consistent with VEXAS syndrome. We describe the first case of EBV-associated HLH in a patient diagnosed with VEXAS syndrome. Early identification of this syndrome will be important in order to offer potential therapies before life-threatening complications arise.

Rare presentation of FDX2-related disorder and untargeted global metabolomics findings.

We present the case of a 20-year-old male with a history of myopathy and multiple episodes of rhabdomyolysis, and lactic acidosis. He needed hemodialysis for severe rhabdomyolysis-related acute renal failure at the time of initial presentation (age 10 years). Exome sequencing detected a homozygous likely pathogenic variant in FDX2 (c.12G>T, p.M4I). The FDX2 gene encodes a mitochondrial protein, ferredoxin 2, that is involved in the biogenesis of Fe-S clusters. Biallelic pathogenic variants in FDX2 have previously been associated with episodic mitochondrial myopathy with or without optic atrophy and reversible leukoencephalopathy. Only two cases with FDX2-related rhabdomyolysis as a predominant feature have been reported in medical literature. Here, we report a third patient with FDX2-related recurrent, severe episodes of rhabdomyolysis and lactic acidosis. He does not have optic atrophy or leukoencephalopathy. This is the oldest patient reported with FDX2-related disorder and he has significantly elevated CK during episodes of rhabdomyolysis. In addition, we describe untargeted global metabolomic findings during an episode of metabolic decompensation, shedding light on the biochemical pathway perturbation associated with this ultra-rare genetic disorder.

Use of dexamethasone in idiopathic, acute pediatric rhabdomyolysis.

Current rhabdomyolysis treatment guidelines vary based on the etiology and diagnosis, yet many cases evade conclusive diagnosis. In these cases, treatment options remain largely limited to fluids and supportive therapy. We present two cases of acute rhabdomyolysis diagnosed in the emergency department: a 5-year-old boy with sudden onset bilateral flank pain, and a 13-year-old boy with 2-3 days of worsening pectoral and shoulder pain. Each patient had a prior similar episode requiring hospitalization in the past. The 5-year-old had no inciting trauma or trigger, medication use, or illness. The 13-year-old previously had an upper respiratory infection during the week prior and had been strenuously exercising at the time of onset. Genetic testing results were unknown for both patients during their hospitalizations, and insurance and other barriers led to delay. Later results for the first patient revealed a heterozygous deletion in intron 19 on the LPIN1 gene interpreted as a variant of unknown significance. During their hospitalizations, both children were started on intravenous (i.v.) fluids, and creatine kinase (CK) initially trended downward, but then began to rise or plateau. After reviewing the cases, prior literature, and anecdotal evidence of benefit from corticosteroid therapy in rhabdomyolysis with our consultant metabolic physicians, dexamethasone was initiated. In both patients, dexamethasone use correlated with relief of patient symptoms, significantly decreased CK value, and our ability to discharge these patients home quickly. Our cases, discussion, and literature review all lead to the consideration of the use of dexamethasone in conjunction with standard therapy for acute rhabdomyolysis.

Whole exome sequencing in patients with Williams-Beuren syndrome followed by disease modeling in mice points to four novel pathways that may modify stenosis risk.

Supravalvular aortic stenosis (SVAS) is a narrowing of the aorta caused by elastin (ELN) haploinsufficiency. SVAS severity varies among patients with Williams-Beuren syndrome (WBS), a rare disorder that removes one copy of ELN and 25-27 other genes. Twenty percent of children with WBS require one or more invasive and often risky procedures to correct the defect while 30% have no appreciable stenosis, despite sharing the same basic genetic lesion. There is no known medical therapy. Consequently, identifying genes that modify SVAS offers the potential for novel modifier-based therapeutics. To improve statistical power in our rare-disease cohort (N = 104 exomes), we utilized extreme-phenotype cohorting, functional variant filtration and pathway-based analysis. Gene set enrichment analysis of exome-wide association data identified increased adaptive immune system variant burden among genes associated with SVAS severity. Additional enrichment, using only potentially pathogenic variants known to differ in frequency between the extreme phenotype subsets, identified significant association of SVAS severity with not only immune pathway genes, but also genes involved with the extracellular matrix, G protein-coupled receptor signaling and lipid metabolism using both SKAT-O and RQTest. Complementary studies in Eln+/-; Rag1-/- mice, which lack a functional adaptive immune system, showed improvement in cardiovascular features of ELN insufficiency. Similarly, studies in mixed background Eln+/- mice confirmed that variations in genes that increase elastic fiber deposition also had positive impact on aortic caliber. By using tools to improve statistical power in combination with orthogonal analyses in mice, we detected four main pathways that contribute to SVAS risk.

Homozygous splice-variants in human ARV1 cause GPI-anchor synthesis deficiency.

BACKGROUND: Mutations in the ARV1 Homolog, Fatty Acid Homeostasis Modulator (ARV1), have recently been described in association with early infantile epileptic encephalopathy 38. Affected individuals presented with epilepsy, ataxia, profound intellectual disability, visual impairment, and central hypotonia. In S. cerevisiae, Arv1 is thought to be involved in sphingolipid metabolism and glycophosphatidylinositol (GPI)-anchor synthesis. The function of ARV1 in human cells, however, has not been elucidated. METHODS: Mutations were discovered through whole exome sequencing and alternate splicing was validated on the cDNA level. Expression of the variants was determined by qPCR and Western blot. Expression of GPI-anchored proteins on neutrophils and fibroblasts was analyzed by FACS and immunofluorescence microscopy, respectively. RESULTS: Here we describe seven patients from two unrelated families with biallelic splice mutations in ARV1. The patients presented with early onset epilepsy, global developmental delays, profound hypotonia, delayed speech development, cortical visual impairment, and severe generalized cerebral and cerebellar atrophy. The splice variants resulted in decreased ARV1 expression and significant decreases in GPI-anchored protein on the membranes of neutrophils and fibroblasts, indicating that the loss of ARV1 results in impaired GPI-anchor synthesis. CONCLUSION: Loss of GPI-anchored proteins on our patients' cells confirms that the yeast Arv1 function of GPI-anchor synthesis is conserved in humans. Overlap between the phenotypes in our patients and those reported for other GPI-anchor disorders suggests that ARV1-deficiency is a GPI-anchor synthesis disorder.