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Objectives: To evaluate the efficacy of ChatGPT 4 (GPT-4) in delivering genetic information about BRCA1, HFE, and MLH1, building on previous findings with ChatGPT 3.5 (GPT-3.5). To focus on assessing the utility, limitations, and ethical implications of using ChatGPT in medical settings., Materials and Methods: A structured survey was developed to assess GPT-4's clinical value. An expert panel of genetic counselors and clinical geneticists evaluated GPT-4's responses to these questions. We also performed comparative analysis with GPT-3.5, utilizing descriptive statistics and using Prism 9 for data analysis., Results: The findings indicate improved accuracy in GPT-4 over GPT-3.5 (P < .0001). However, notable errors in accuracy remained. The relevance of responses varied in GPT-4, but was generally favorable, with a mean in the "somewhat agree" range. There was no difference in performance by disease category. The 7-question subset of the Bot Usability Scale (BUS-15) showed no statistically significant difference between the groups but trended lower in the GPT-4 version., Discussion and Conclusion: The study underscores GPT-4's potential role in genetic education, showing notable progress yet facing challenges like outdated information and the necessity of ongoing refinement. Our results, while showing promise, emphasizes the importance of balancing technological innovation with ethical responsibility in healthcare information delivery., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Medical Informatics Association.)

In a previous pathway-based, extreme phenotype study, we identified 1064 variants associated with supravalvar aortic stenosis (SVAS) severity in people with Williams syndrome (WS) and either no SVAS or surgical SVAS. Here, we use those variants to develop and test polygenic risk scores (PRS). We used the clumping and thresholding (CT) approach on the full 1064 variants and a 427-variant subset that was part of 13 biologically relevant pathways identified in the previous study. We also used a lasso approach on the full set. We were able to achieve an area under the curve (AUC) of >0.99 for the two CT PRS methods, using only 622 and 320 variants respectively when 2/3 of the initial 217 participants data were used for training and 1/3 for testing. The lasso performed less well. We then evaluated the performance of those PRS variant sets on an additional group of 138 patients with WS with intermediate severity SVAS and found a misclassification rate of <10% between the surgical and intermediate groups, suggesting potential for clinical utility of the score., Competing Interests: Disclosures: The authors report no conflicts.

Variation in the elastin gene ( ELN ) may contribute to connective tissue disease beyond the known disease associations of Supravalvar Aortic Stenosis and Cutis Laxa. Exome data from MyCode Community Health Initiative participants were analyzed for ELN rare variants (mean allele frequency <1%, not currently annotated as benign). Participants with variants of interest underwent phenotyping by dual chart review using a standardized abstraction tool. Additionally, all rare variants that met inclusion criteria were collapsed into an ELN gene burden score to perform a Phenome-wide Association Study (PheWAS). Two hundred and ninety-six eligible participants with relevant ELN variants were identified from 184,293 MyCode participants. One hundred and three of 254 living participants (41%) met phenotypic criteria, most commonly aortic hypoplasia, arterial dilation, aneurysm, and dissection, and connective tissue abnormalities. ELN variation was significantly (P <2.8×10 -5 ) associated with "arterial dissection" in the PheWAS and two connective tissue Phecodes approached significance. Variation in ELN is associated with connective tissue pathology beyond classic phenotypes., Etoc Blurb: Carriers of variants of interest in the elastin gene ( ELN ) were evaluated for presence of findings that could be associated with the variation. Chart review and Phenome-wide Association Studies were used. Results are consistent with variation in ELN being associated with findings affecting elastic tissues beyond classic phenotypes.

Williams-Beuren syndrome (WBS) is a rare genetic condition caused by a chromosomal microdeletion at 7q11.23. It is a multisystem disorder characterized by distinct facies, intellectual disability, and supravalvar aortic stenosis (SVAS). Those with WBS are at increased risk of sudden death, but mechanisms underlying this remain poorly understood. We recently demonstrated autonomic abnormalities in those with WBS that are associated with increased susceptibility to arrhythmia and sudden cardiac death (SCD). A recently introduced method for heart rate variability (HRV) analysis called "heart rate fragmentation" (HRF) correlates with adverse cardiovascular events (CVEs) and death in studies where heart rate variability (HRV) failed to identify high-risk subjects. Some argue that HRF quantifies nonautonomic cardiovascular modulators. We, therefore, sought to apply HRF analysis to a WBS cohort to determine 1 ) if those with WBS show differences in HRF compared with healthy controls and 2 ) if HRF helps characterize HRV abnormalities in those with WBS. Similar to studies of those with coronary artery disease (CAD) and atherosclerosis, we found significantly higher HRF (4 out of 7 metrics) in those with WBS compared with healthy controls. Multivariable analyses showed a weak-to-moderate association between HRF and HRV, suggesting that HRF may reflect HRV characteristics not fully captured by traditional HRV metrics (autonomic markers). We also introduce a new metric inspired by HRF methodology, significant acute rate drop (SARD), which may detect vagal activity more directly. HRF and SARD may improve on traditional HRV measures to identify those at greatest risk for SCD both in those with WBS and in other populations. NEW & NOTEWORTHY This work is the first to apply heart rate fragmentation analyses to individuals with Williams syndrome and posits that the heart rate fragmentation parameter W 3 may enable detection and investigation of phenomena underlying the proarrhythmic short-long-short RR interval sequences paradigm known to precede ventricular fibrillation and ventricular tachycardia. It also forwards a novel method for quantifying sinus arrhythmia and sinus pauses that likely correlate with parasympathetic activity.

Williams syndrome (WS) is a multi-system condition caused by the deletion of 25-27 coding genes on human chromosome 7. Irritability, gastrointestinal (GI) reflux and slow growth are commonly reported in infants with WS, but less data exist regarding GI concerns in older children and adults with the condition. This study evaluates 62 individuals with WS (31 children aged 3-17, and 31 adults aged 18-62) as well as 36 pediatric and adult controls to assess current and historical rates of common GI symptoms. Data were evaluated using a regression model including age, sex, self-reported race, and diagnosis. Symptoms including food intolerance, reflux, dysphagia, choking/gagging, vomiting, constipation, bloating, diarrhea, hematochezia, rectal prolapse, abdominal pain, and weight loss are more common in those with WS relative to controls. In addition, people with WS utilize more GI medications, specialty care, procedures, and supplemental feeds. Among those with WS, symptoms were present at similar rates in children and adults, except for diverticular disease, which was not noted until adulthood. GI symptoms are frequent in people with WS and serve as a significant source of morbidity., (Published 2024. This article is a U.S. Government work and is in the public domain in the USA. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Background: We aimed to describe the frequency and yield of genetic testing in supravalvar aortic stenosis (SVAS) following negative evaluation for Williams-Beuren syndrome (WS)., Methods and Results: This retrospective cohort study included patients with SVAS at our institution who had a negative evaluation for WS from May 1991 to September 2021. SVAS was defined as (1) peak supravalvar velocity of ≥2 meters/second, (2) sinotubular junction or ascending aortic Z score <-2.0, or (3) sinotubular junction Z score <-1.5 with family history of SVAS. Patients with complex congenital heart disease, aortic valve disease as the primary condition, or only postoperative SVAS were excluded. Genetic testing and diagnoses were reported. Of 162 patients who were WS negative meeting inclusion criteria, 61 had genetic testing results available (38%). Chromosomal microarray had been performed in 44 of 61 and was nondiagnostic for non-WS causes of SVAS. Sequencing of 1 or more genes was performed in 47 of 61. Of these, 39 of 47 underwent ELN sequencing, 20 of 39 (51%) of whom had a diagnostic variant. Other diagnoses made by gene sequencing were Noonan syndrome (3 PTPN11 , 1 RIT1) , Alagille syndrome (3 JAG1 ), neurofibromatosis (1 NF1 ), and homozygous familial hypercholesterolemia (1 LDLR1 ). Overall, sequencing was diagnostic in 29 of 47 (62%)., Conclusions: When WS is excluded, gene sequencing for SVAS is high yield, with the highest yield for the ELN gene. Therefore, we recommend gene sequencing using a multigene panel or exome analysis. Hypercholesterolemia can also be considered in individuals bearing the stigmata of this disease.

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.

Vascular aging affects multiple organ systems, including the brain, where it can lead to vascular dementia. However, a concrete understanding of how aging specifically affects the brain vasculature, along with molecular readouts, remains vastly incomplete. Here, we demonstrate that aging is associated with a marked decline in Notch3 signaling in both murine and human brain vessels. To clarify the consequences of Notch3 loss in the brain vasculature, we used single-cell transcriptomics and found that Notch3 inactivation alters regulation of calcium and contractile function and promotes a notable increase in extracellular matrix. These alterations adversely impact vascular reactivity, manifesting as dilation, tortuosity, microaneurysms, and decreased cerebral blood flow, as observed by MRI. Combined, these vascular impairments hinder glymphatic flow and result in buildup of glycosaminoglycans within the brain parenchyma. Remarkably, this phenomenon mirrors a key pathological feature found in brains of patients with CADASIL, a hereditary vascular dementia associated with NOTCH3 missense mutations. Additionally, single-cell RNA sequencing of the neuronal compartment in aging Notch3-null mice unveiled patterns reminiscent of those observed in neurodegenerative diseases. These findings offer direct evidence that age-related NOTCH3 deficiencies trigger a progressive decline in vascular function, subsequently affecting glymphatic flow and culminating in neurodegeneration.

BAZ1B is one of 25-27 coding genes deleted in canonical Williams syndrome, a multi-system disorder causing slow growth, vascular stenosis, and gastrointestinal complaints, including constipation. BAZ1B is involved in (among other processes) chromatin organization, DNA damage repair, and mitosis, suggesting reduced BAZ1B may contribute to Williams syndrome symptoms. In mice, loss of Baz1b causes early neonatal death. 89.6% of Baz1b -/- mice die within 24 h of birth without vascular anomalies or congenital heart disease (except for patent ductus arteriosus). Some (<50%) Baz1b -/- were noted to have prolonged neonatal cyanosis, patent ductus arteriosus, or reduced lung aeration, and none developed a milk spot. Meanwhile, 35.5% of Baz1b +/- mice die over the first three weeks after birth. Surviving Baz1b heterozygotes grow slowly (with variable severity). 66.7% of Baz1b +/- mice develop bowel dilation, compared to 37.8% of wild-type mice, but small bowel and colon transit studies were normal. Additionally, enteric neuron density appeared normal in Baz1b -/- mice except in distal colon myenteric plexus, where neuron density was modestly elevated. Combined with several rare phenotypes (agnathia, microphthalmia, bowel dilation) recovered, our work confirms the importance of BAZ1B in survival and growth and suggests that reduced copy number of BAZ1B may contribute to the variability in Williams syndrome phenotypes., Competing Interests: Declaration of competing interest ROH was a consultant for BlueRock Therapeutics and for Takeda., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background/aims: To characterise the ocular manifestations of Williams-Beuren syndrome (WBS) and compare these to patients with isolated elastin mediated supravalvular aortic stenosis (SVAS)., Methods: Fifty-seven patients with a diagnosis of WBS and five with SVAS underwent comprehensive ophthalmic evaluation at the National Institutes of Health from 2017 to 2020, including best-corrected visual acuity, slit-lamp biomicroscopy, optical biometry, dilated fundus examination, optical coherence tomography and colour fundus imaging., Results: Mean age of the 57 WBS patients was 20.3 years (range 3-60 years). Best-corrected visual acuity ranged from 20/20 to 20/400 with mean spherical equivalent near plano OU. Twenty-four eyes (21.8%) had an axial length (AL) less than 20.5 mm and 38 eyes (34.5%) had an AL measuring 20.5-22.0 mm. Stellate iris and retinal arteriolar tortuosity were noted in 30 (52.6%) and 51 (89.5%) WBS patients, respectively. Novel retinal findings in WBS included small hypopigmented retinal deposits (OD 29/57, OS 27/57) and broad foveal pit contour (OD 44/55, OS 42/51). Of the five patients with SVAS, none had stellate iris or broad foveal pit contour while 2/5 had retinal arteriolar tortuosity., Conclusion: WBS is a complex multisystem genetic disorder with diverse ophthalmic findings that differ from those seen in isolated elastin mediated SVAS. These results suggest other genes within the WBS critical region, aside from ELN , may be involved in observed ocular phenotypes and perhaps broader ocular development. Furthermore, retinal arteriolar tortuosity may provide future insight into systemic vascular findings in WBS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Mapping cranial vasculature and adjacent neurovascular interfaces in their entirety will enhance our understanding of central nervous system function in any physiologic state. We present a workflow to visualize in situ murine vasculature and surrounding cranial structures using terminal polymer casting of vessels, iterative sample processing and image acquisition, and automated image registration and processing. While this method does not obtain dynamic imaging due to mouse sacrifice, these studies can be performed before sacrifice and processed with other acquired images. For complete details on the use and execution of this protocol, please refer to Rosenblum et al. 1 ., Competing Interests: Declaration of interests J.S.R., Vikram Chandrashekhar, and Vibhu Chandrashekhar are affiliated with Neurosimplicity, LLC, which is a medical device and technology company focusing on medical image processing. The content of this manuscript does not necessarily reflect the views, policies, or opinions of the U.S. Department of Health and Human Services. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as an actual or implied endorsement of such products by the United States Government. Neurosimplicity, LLC has patent applications directed to the technology described in this manuscript., (Published by Elsevier Inc.)

Background: Williams-Beuren syndrome (WBS) (Online Mendelian Inheritance in Man #194050) is a rare genetic multisystem disorder resulting from a chromosomal microdeletion at 7q11.23. The condition is characterized by distinct facies, intellectual disability, and supravalvar aortic stenosis. Those with WBS have an increased risk of sudden death, but mechanisms underlying this phenotype are incompletely understood., Objectives: The aim of this study was to quantify and compare autonomic activity as reflected by heart rate variability (HRV) measures in a cohort of individuals with WBS (n = 18) and age- and sex-matched control subjects (n = 18)., Methods: We performed HRV analysis on 24-hour electrocardiography recordings using nonlinear, time and frequency domain analyses on a cohort of subjects with WBS and age- and sex-matched control subjects enrolled in a prospective cross-sectional study designed to characterize WBS disease natural history., Results: WBS subjects demonstrated diminished HRV (reflected by the SD of the NN intervals [P = 0.0001], SD of the average NN interval for 5-minute intervals over 24 hours [P < 0.0001], average of the 5-minute SDs of NN intervals for 24 hours [P = 0.0002], root mean square of successive differences of NN intervals [P = 0.0004], short axis of the Poincaré plot (SD1) [P < 0.0001], and long axis of the Poincaré plot [P < 0.0001]) and indirect markers of parasympathetic activity (reflected by the percent of NN intervals different from previous by 50% or more of local average [P < 0.0007], root mean square of successive differences of NN intervals [P = 0.0004], natural log high-frequency power [P = 0.0038], and SD1 [P < 0.0001]). Additional parameters were also significantly different, including natural log very low-frequency power (decreased; P = 0.0002), natural log low-frequency power (decreased; P = 0.0024), and SD1 divided by the long axis of the Poincaré plot (decreased; P < 0.0001)., Conclusions: Individuals with WBS demonstrate significant HRV abnormalities consistent with diminished autonomic reserve. Future studies will be needed to determine the relationship between autonomic dysregulation observed and sudden death risk seen in these patients. (Impact of Elastin Mediated Vascular Stiffness on End Organs; NCT02840448)., Competing Interests: Funding Support and Author Disclosures Funding for this work was provided by National Heart, Lung, and Blood Institute Division of Intramural Research intramural research programs grants ZIA HL 006210 and ZIA HL 006212. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

The NIH Toolbox Cognition Battery (NIHTB-CB) was developed for epidemiological and longitudinal studies across a wide age span. Such a tool may be useful for intervention trials in conditions characterized by intellectual disability (ID), such as Williams syndrome (WS). Three NIHTB-CB tasks, including two executive functioning (Flanker, Dimensional Change Card Sort) and one episodic memory (Picture Sequence Memory) task, were given to 47 individuals with WS, ages 4 to 50, to evaluate feasibility (i.e., proportion of valid administrations) in this population. Findings indicated that NIHTB-CB tests showed good feasibility. Flanker and DCCS age-corrected scores were negatively correlated with age and showed floor effects, indicating these scores may not be useful for quantifying performance on these NIHTB-CB tests in ID., (©AAIDD.)

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., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The size of the aorta varies in the healthy population and is influenced by a series of mostly common and lower-impact genomic variants. Rare, high-impact variants driving Mendelian diseases of stenosis and aneurysm extend the limits of aortic size out of the typical range. Pathology at both ends of the spectrum is governed by overlapping pathways and processes, such as those affecting structure, integrity, and function of the aorta. As such, aortopathies across the full spectrum from stenosis to aneurysm are likely modified by a similar constellation of common and rarer genetic variants in a directional, weighted, and context-dependent manner. Here, we discuss the role of modifiers in aortic disease by presenting an example of two opposing rare diseases and highlight the need to consider the influence of background genome variation when considering disease outcomes., (Published by Elsevier Ltd.)

Elastin provides recoil to tissues that stretch such as the lung, blood vessels, and skin. It is deposited in a brief window starting in the prenatal period and extending to adolescence in vertebrates, and then slowly turns over. Elastin insufficiency is seen in conditions such as Williams-Beuren syndrome and elastin-related supravalvar aortic stenosis, which are associated with a range of vascular and connective tissue manifestations. Regulation of the elastin ( ELN ) gene occurs at multiple levels including promoter activation/inhibition, mRNA stability, interaction with microRNAs, and alternative splicing. However, these mechanisms are incompletely understood. Better understanding of the processes controlling ELN gene expression may improve medicine's ability to intervene in these rare conditions, as well as to replace age-associated losses by re-initiating elastin production. This review describes what is known about the ELN gene promoter structure, transcriptional regulation by cytokines and transcription factors, and posttranscriptional regulation via mRNA stability and micro-RNA and highlights new approaches that may influence regenerative medicine.

Clinical investigations have established that vascular-associated medical conditions are significant risk factors for various kinds of dementia. And yet, we are unable to associate certain types of vascular deficiencies with specific cognitive impairments. The reasons for this are many, not the least of which are that most vascular disorders are multi-factorial and the development of vascular dementia in humans is often a multi-year or multi-decade progression. To better study vascular disease and its underlying causes, the National Heart, Lung, and Blood Institute of the National Institutes of Health has invested considerable resources in the development of animal models that recapitulate various aspects of human vascular disease. Many of these models, mainly in the mouse, are based on genetic mutations, frequently using single-gene mutations to examine the role of specific proteins in vascular function. These models could serve as useful tools for understanding the association of specific vascular signaling pathways with specific neurological and cognitive impairments related to dementia. To advance the state of the vascular dementia field and improve the information sharing between the vascular biology and neurobehavioral research communities, National Heart, Lung, and Blood Institute convened a workshop to bring in scientists from these knowledge domains to discuss the potential utility of establishing a comprehensive phenotypic cognitive assessment of a selected set of existing mouse models, representative of the spectrum of vascular disorders, with particular attention focused on age, sex, and rigor and reproducibility. The workshop highlighted the potential of associating well-characterized vascular disease models, with validated cognitive outcomes, that can be used to link specific vascular signaling pathways with specific cognitive and neurobehavioral deficits.

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 TGFβ-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.

Williams−Beuren syndrome (WS) results from the deletion of 25−27 coding genes, including elastin (ELN), on human chromosome 7q11.23. Elastin provides recoil to tissues; emphysema and chronic obstructive pulmonary disease have been linked to its destruction. Consequently, we hypothesized that elastin insufficiency would predispose to obstructive features. Twenty-two adults with WS (aged 18−55) and controls underwent pulmonary function testing, 6 min walk, and chest computed tomography (CT). Lung and airspace dimensions were assessed in Eln+/− and control mice via microCT and histology. The forced expiratory volume in 1 s (FEV1) and the ratio of FEV1 to forced vital capacity (FVC) were lower in adults with WS (p < 0.0001 and p < 0.05, respectively). The FEV1/FVC ratio was more frequently below the lower limit of normal in cases (p < 0.01). The ratio of residual volume to total lung capacity (RV/TLC, percent predicted) was higher in cases (p < 0.01), suggesting air trapping. People with WS showed reduced exercise capacity (p < 0.0001). In Eln+/− mice, ex vivo lung volumes were increased (p < 0.0001), with larger airspaces (p < 0.001). Together these data show that elastin insufficiency impacts lung physiology in the form of increased air trapping and obstruction, suggesting a role for lung function monitoring in adults with WS.

Background: Williams Beuren syndrome (WBS) is a recurrent microdeletion disorder that removes one copy of elastin ( ELN ), resulting in large artery vasculopathy. Early stenosis of the pulmonary vascular tree is common, but few data are available on longer-term implications of the condition., Methods: Computed tomography (CT) angiogram ( n = 11) and echocardiogram ( n = 20) were performed in children with WBS aged 3.4-17.8 years. Controls ( n = 11, aged 4.4-16.8 years) also underwent echocardiogram. Eln +/- mice were analyzed by invasive catheter, echocardiogram, micro-CT (μCT), histology, and pressure myography. We subsequently tested whether minoxidil resulted in improved pulmonary vascular endpoints., Results: WBS participants with a history of main or branch pulmonary artery (PA) stenosis requiring intervention continued to exhibit increased right ventricular systolic pressure (RVSP, echocardiogram) relative to their peers without intervention ( p < 0.01), with no clear difference in PA size. Untreated Eln +/- mice also show elevated RVSP by invasive catheterization ( p < 0.0001), increased normalized right heart mass ( p < 0.01) and reduced caliber branch PAs by pressure myography ( p < 0.0001). Eln +/- main PA medias are thickened histologically relative to Eln +/+ ( p < 0.0001). Most Eln +/- phenotypes are shared by both sexes, but PA medial thickness is substantially greater in Eln +/- males ( p < 0.001). Eln +/- mice showed more acute proximal branching angles ( p < 0.0001) and longer vascular segment lengths ( p < 0.0001) (μCT), with genotype differences emerging by P7. Diminished PA acceleration time ( p < 0.001) and systolic notching ( p < 0.0001) were also observed in Eln +/- echocardiography. Vascular casting plus μCT revealed longer generation-specific PA arcade length ( p < 0.0001), with increased PA branching detectable by P90 ( p < 0.0001). Post-weaning minoxidil decreased RVSP ( p < 0.01) and normalized PA caliber ( p < 0.0001) but not early-onset proximal branching angle or segment length, nor later-developing peripheral branch number., Conclusions: Vascular deficiencies beyond arterial caliber persist in individuals with WBS who have undergone PA stenosis intervention. Evaluation of Eln +/- mice reveals complex vascular changes that affect the proximal and distal vasculatures. Minoxidil, given post-weaning, decreases RVSP and improves lumen diameter, but does not alter other earlier-onset vascular patterns. Our data suggest additional therapies including minoxidil could be a useful adjunct to surgical therapy, and future trials should be considered., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Knutsen, Gober, Kronquist, Kaur, Donahue, Springer, Yu, Chen, Fu, Choobdar, Nguyen, Osgood, Freeman, Raja, Levin and Kozel.)

Gene dosage disorders (GDDs) constitute a major class of genetic risks for psychopathology, but there is considerable debate regarding the extent to which different GDDs induce different psychopathology profiles. The current research speaks to this debate by compiling and analyzing dimensional measures of several autism-related traits (ARTs) across seven diverse GDDs. The sample included 350 individuals with one of 7 GDDs, as well as reference idiopathic autism spectrum disorder (ASD; n = 74) and typically developing control (TD; n = 171) groups. The GDDs were: Down, Williams-Beuren, and Smith-Magenis (DS, WS, SMS) syndromes, and varying sex chromosome aneuploidies ("plusX", "plusXX", "plusY", "plusXY"). The Social Responsiveness Scale (SRS-2) was used to measure ARTs at different levels of granularity-item, subscale, and total. General linear models were used to examine ART profiles in GDDs, and machine learning was used to predict genotype from SRS-2 subscales and items. These analyses were completed with and without covariation for cognitive impairment. Twelve of all possible 21 pairwise GDD group contrasts showed significantly different ART profiles (7/21 when co-varying for IQ, all Bonferroni-corrected). Prominent GDD-ART associations in post hoc analyses included relatively preserved social motivation in WS and relatively low levels of repetitive behaviors in plusX. Machine learning revealed that GDD group could be predicted with plausible accuracy (~60-80%) even after controlling for IQ. GDD effects on ARTs are influenced by GDD subtype and ART dimension. This observation has consequences for mechanistic, clinical, and translational aspects of psychiatric neurogenetics., (© 2022. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

There is ample evidence supporting a role for angiotensin II type 2 receptor (AT 2 R) in counterbalancing the effects of angiotensin II (ang II) through the angiotensin II type 1 receptor by promoting vasodilation and having anti-inflammatory effects. Elastin insufficiency in both humans and mice results in large artery stiffness and systolic hypertension. Unexpectedly, mesenteric arteries from elastin insufficient ( Eln +/- ) mice were shown to have significant vasoconstriction to AT 2 R agonism in vitro suggesting that AT 2 R may have vasoconstrictor effects in elastin insufficiency. Given the potential promise for the use of AT 2 R agonists clinically, the goal of this study was to determine whether AT 2 R has vasoconstrictive effects in elastin insufficiency in vivo . To avoid off-target effects of agonists and antagonists, mice lacking AT 2 R ( Agtr2 -/ Y ) were bred to Eln +/- mice and cardiovascular parameters were assessed in wild-type (WT), Agtr2 -/ Y , Eln +/- , and Agtr2 -/ Y ;Eln +/- littermates. As previously published, Agtr2 -/ Y mice were normotensive at baseline and had no large artery stiffness, while Eln +/- mice exhibited systolic hypertension and large artery stiffness. Loss of AT 2 R in Eln +/- mice did not affect large artery stiffness or arterial structure but resulted in significant reduction of both systolic and diastolic blood pressure. These data support a potential vasocontractile role for AT 2 R in elastin insufficiency. Careful consideration and investigation are necessary to determine the patient population that might benefit from the use of AT 2 R agonists., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lin, Roth, Kozel, Mecham and Halabi.)

Purpose: Creatine transporter deficiency (CTD) is a rare X-linked disorder of creatine transport caused by pathogenic variants in SLC6A8 (Xq28). CTD features include developmental delay, seizures, and autism spectrum disorder. This study was designed to investigate CTD cardiac phenotype and sudden death risk., Methods: We performed a cross-sectional analysis of CTD males between 2017 and 2020. Subjects underwent evaluation with electrocardiogram (ECG), echocardiography, and ambulatory ECG with comparable analysis in creatine transporter deficient mice (Slc6a8 -/y ) using ECG, echocardiography, exercise testing, and indirect calorimetry., Results: Eighteen subjects with CTD (18 males, age 7.4 [3.8] years) were evaluated: seven subjects (39%) had QTc ≥ 470 milliseconds: 510.3 ± 29.0 vs. 448.3 ± 15.9, P < 0.0001. The QTc ≥ 470 milliseconds cohort had increased left ventricular internal dimension (diastole) ([LVIDd] Z-score: 0.22 ± 0.74, n = 7 vs. -0.93 ± 1.0, n = 11, P = 0.0059), and diminished left ventricular posterior wall dimension (diastole) ([LVPWDd, in mm]: 5.0 ± 0.6, n = 7 vs. 5.7 ± 0.8, n = 11, P = 0.0183), when compared to subjects with normal or borderline QTc prolongation. Similar ECG and echocardiographic abnormalities were seen in Slc6a8 -/y mice. Additionally, Slc6a8 -/y mice had diminished survival (65%)., Conclusion: Prolonged QTc and abnormal echocardiographic parameters consistent with developing cardiomyopathy are seen in some male subjects with CTD. Slc6a8 -/y mice recapitulated these cardiac abnormalities. Male CTD subjects may be at increased risk for cardiac dysfunction and sudden death., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Maternal loss of imprinting (LOI) at the H19/IGF2 locus results in biallelic IGF2 and reduced H19 expression and is associated with Beckwith--Wiedemann syndrome (BWS). We use mouse models for LOI to understand the relative importance of Igf2 and H19 mis-expression in BWS phenotypes. Here we focus on cardiovascular phenotypes and show that neonatal cardiomegaly is exclusively dependent on increased Igf2 . Circulating IGF2 binds cardiomyocyte receptors to hyperactivate mTOR signaling, resulting in cellular hyperplasia and hypertrophy. These Igf2 -dependent phenotypes are transient: cardiac size returns to normal once Igf2 expression is suppressed postnatally. However, reduced H19 expression is sufficient to cause progressive heart pathologies including fibrosis and reduced ventricular function. In the heart, H19 expression is primarily in endothelial cells (ECs) and regulates EC differentiation both in vivo and in vitro. Finally, we establish novel mouse models to show that cardiac phenotypes depend on H19 lncRNA interactions with Mirlet7 microRNAs., Competing Interests: KP, HL, ZY, JN, AM, CK, RK, DS, CG, BK, KP None, BR none

In pathology protocols, a tissue block, such as one containing a mouse brain or a biopsy sample from a patient, can produce several hundred thin sections. Substantial time may be required to analyse all sections. In cases of uncertainty regarding which sections to focus on, noninvasive scout imaging of intact blocks can help in guiding the pathology procedure. The scouting step is ideally done in a time window of minutes without special sample preparation that may interfere with the pathology procedures. The challenge is to obtain some visibility of unstained tissue structures at sub-10 µm resolution. We explored a novel x-ray tomosynthesis method as a way to maximise contrast-to-noise ratio, a determinant of tissue visibility. It provided a z-stack of thousands of images at 7.3 μm resolution (10% contrast, half-period of 68.5 line pairs/mm), in scans of 5-15 minutes. When compared with micro-CT scans, the straight-line tomosynthesis scan did not need to rotate the sample, which allowed flat samples, such as paraffin blocks, to be kept as close as possible to the x-ray source. Thus, given the same hardware, scan time and resolution, this mode maximised the photon flux density through the sample, which helped in maximising the contrast-to-noise ratio. The tradeoff of tomosynthesis is incomplete 3D information. The microtomosynthesis scanner has scanned 110 unstained human and animal tissue samples as part of their respective pathology protocols. In all cases, the z-stack of images showed tissue structures that guided sectioning or provided correlative structural information. We describe six examples that presented different levels of visibility of soft tissue structures. Additionally, in a set of coronary artery samples from an HIV patient donor, microtomosynthesis made a new discovery of isolated focal calcification in the internal elastic lamina of coronary wall, which was the onset of medial calcific sclerosis in the arteries., (© 2021 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.)

Williams syndrome (WS) is a relatively rare microdeletion disorder that occurs in as many as 1:7,500 individuals. WS arises due to the mispairing of low-copy DNA repetitive elements at meiosis. The deletion size is similar across most individuals with WS and leads to the loss of one copy of 25-27 genes on chromosome 7q11.23. The resulting unique disorder affects multiple systems, with cardinal features including but not limited to cardiovascular disease (characteristically stenosis of the great arteries and most notably supravalvar aortic stenosis), a distinctive craniofacial appearance, and a specific cognitive and behavioural profile that includes intellectual disability and hypersociability. Genotype-phenotype evidence is strongest for ELN, the gene encoding elastin, which is responsible for the vascular and connective tissue features of WS, and for the transcription factor genes GTF2I and GTF2IRD1, which are known to affect intellectual ability, social functioning and anxiety. Mounting evidence also ascribes phenotypic consequences to the deletion of BAZ1B, LIMK1, STX1A and MLXIPL, but more work is needed to understand the mechanism by which these deletions contribute to clinical outcomes. The age of diagnosis has fallen in regions of the world where technological advances, such as chromosomal microarray, enable clinicians to make the diagnosis of WS without formally suspecting it, allowing earlier intervention by medical and developmental specialists. Phenotypic variability is considerable for all cardinal features of WS but the specific sources of this variability remain unknown. Further investigation to identify the factors responsible for these differences may lead to mechanism-based rather than symptom-based therapies and should therefore be a high research priority.

Elastin (ELN) insufficiency leads to the cardiovascular hallmarks of the contiguous gene deletion disorder, Williams-Beuren syndrome, including hypertension and vascular stiffness. Previous studies showed that Williams-Beuren syndrome deletions, which extended to include the NCF1 gene, were associated with lower blood pressure (BP) and reduced vascular stiffness. NCF1 encodes for p47phox, the regulatory component of the NOX1 NADPH oxidase complex that generates reactive oxygen species (ROS) in the vascular wall. Dihydroethidium and 8-hydroxyguanosine staining of mouse aortas confirmed that Eln heterozygotes ( Eln +/- ) had greater ROS levels than the wild-types ( Eln +/+ ), a finding that was negated in vessels cultured without hemodynamic stressors. To analyze the Nox effect on ELN insufficiency, we used both genetic and chemical manipulations. Both Ncf1 haploinsufficiency ( Ncf1 +/- ) and Nox1 insufficiency ( Nox1 -/y ) decreased oxidative stress and systolic BP in Eln +/- without modifying vascular structure. Chronic treatment with apocynin, a p47phox inhibitor, lowered systolic BP in Eln +/- , but had no impact on Eln +/+ controls. In vivo dosing with phenylephrine (PE) produced an augmented BP response in Eln +/- relative to Eln +/+ , and genetic modifications or drug-based interventions that lower Nox1 expression reduced the hypercontractile response to PE in Eln +/- mice to Eln +/+ levels. These results indicate that the mechanical and structural differences caused by ELN insufficiency leading to oscillatory flow can perpetuate oxidative stress conditions, which are linked to hypertension, and that by lowering the Nox1-mediated capacity for vascular ROS production, BP differences can be normalized., (Published by Oxford University Press on behalf of American Physiological Society 2021. This work is written by US Government employees and is in the public domain in the US.)

Mutations in EPAS1, encoding hypoxia-inducible factor-2α (HIF-2α), were previously identified in a syndrome of multiple paragangliomas, somatostatinoma, and polycythemia. HIF-2α, when dimerized with HIF-1β, acts as an angiogenic transcription factor. Patients referred to the NIH for new, recurrent, and/or metastatic paraganglioma or pheochromocytoma were confirmed for EPAS1 gain-of-function mutation; imaging was evaluated for vascular malformations. We evaluated the Epas1A529V transgenic syndrome mouse model, corresponding to the mutation initially detected in the patients (EPAS1A530V), for vascular malformations via intravital 2-photon microscopy of meningeal vessels, terminal vascular perfusion with Microfil silicate polymer and subsequent intact ex vivo 14T MRI and micro-CT, and histologic sectioning and staining of the brain and identified pathologies. Further, we evaluated retinas from corresponding developmental time points (P7, P14, and P21) and the adult dura via immunofluorescent labeling of vessels and confocal imaging. We identified a spectrum of vascular malformations in all 9 syndromic patients and in all our tested mutant mice. Patient vessels had higher variant allele frequency than adjacent normal tissue. Veins of the murine retina and intracranial dura failed to regress normally at the expected developmental time points. These findings add vascular malformation as a new clinical feature of EPAS1 gain-of-function syndrome.

The delineation of disease entities is complex, yet recent advances in the molecular characterization of diseases provide opportunities to designate diseases in a biologically valid manner. Here, we have formalized an approach to the delineation of Mendelian genetic disorders that encompasses two distinct but inter-related concepts: (1) the gene that is mutated and (2) the phenotypic descriptor, preferably a recognizably distinct phenotype. We assert that only by a combinatorial or dyadic approach taking both of these attributes into account can a unitary, distinct genetic disorder be designated. We propose that all Mendelian disorders should be designated as "GENE-related phenotype descriptor" (e.g., "CFTR-related cystic fibrosis"). This approach to delineating and naming disorders reconciles the complexity of gene-to-phenotype relationships in a simple and clear manner yet communicates the complexity and nuance of these relationships., (Copyright © 2020 American Society of Human Genetics. All rights reserved.)

Background: Holoprosencephaly is the most common malformation of the forebrain (1 in 250 embryos) with severe consequences for fetal and child development. This study evaluates nongenetic factors associated with holoprosencephaly risk, severity, and gene-environment interactions., Methods: For this retrospective case control study, we developed an online questionnaire focusing on exposures to common and rare toxins/toxicants before and during pregnancy, nutritional factors, maternal health history, and demographic factors. Patients with holoprosencephaly were primarily ascertained from our ongoing genetic and clinical studies of holoprosencephaly. Controls included children with Williams-Beuren syndrome (WBS) ascertained through online advertisements in a WBD support group and fliers., Results: Difference in odds of exposures between cases and controls as well as within cases with varying holoprosencephaly severity were studied. Cases included children born with holoprosencephaly (n = 92) and the control group consisted of children with WBS (n = 56). Pregnancy associated risk associated with holoprosencephaly included maternal pregestational diabetes (9.2% of cases and 0 controls, p = .02), higher alcohol consumption (adjusted odds ratio [aOR], 1.73; 95% CI, 0.88-15.71), and exposure to consumer products such as aerosols or sprays including hair sprays (aOR, 2.46; 95% CI, 0.89-7.19). Significant gene-environment interactions were identified including for consumption of cheese (p < .05) and espresso drinks (p = .03)., Conclusion: The study identifies modifiable risk factors and gene-environment interactions that should be considered in future prevention of holoprosencephaly. Studies with larger HPE cohorts will be needed to confirm these findings., (© 2020 Wiley Periodicals LLC.)

There are more than 7000 described rare diseases, most lacking specific treatment. Autosomal-dominant hyper-IgE syndrome (AD-HIES, also known as Job's syndrome) is caused by mutations in STAT3. These patients present with immunodeficiency accompanied by severe nonimmunological features, including skeletal, connective tissue, and vascular abnormalities, poor postinfection lung healing, and subsequent pulmonary failure. No specific therapies are available for these abnormalities. Here, we investigated underlying mechanisms in order to identify therapeutic targets. Histological analysis of skin wounds demonstrated delayed granulation tissue formation and vascularization during skin-wound healing in AD-HIES patients. Global gene expression analysis in AD-HIES patient skin fibroblasts identified deficiencies in a STAT3-controlled transcriptional network regulating extracellular matrix (ECM) remodeling and angiogenesis, with hypoxia-inducible factor 1α (HIF-1α) being a major contributor. Consistent with this, histological analysis of skin wounds and coronary arteries from AD-HIES patients showed decreased HIF-1α expression and revealed abnormal organization of the ECM and altered formation of the coronary vasa vasorum. Disease modeling using cell culture and mouse models of angiogenesis and wound healing confirmed these predicted deficiencies and demonstrated therapeutic benefit of HIF-1α-stabilizing drugs. The study provides mechanistic insights into AD-HIES pathophysiology and suggests potential treatment options for this rare disease.

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., (Published by Oxford University Press 2020.)

Blood vessels form intricate networks in 3-dimensional space. Consequently, it is difficult to visually appreciate how vascular networks interact and behave by observing the surface of a tissue. This method provides a means to visualize the complex 3-dimensional vascular architecture of the lung. To accomplish this, a catheter is inserted into the pulmonary artery and the vasculature is simultaneously flushed of blood and chemically dilated to limit resistance. Lungs are then inflated through the trachea at a standard pressure and the polymer compound is infused into the vascular bed at a standard flow rate. Once the entire arterial network is filled and allowed to cure, the lung vasculature may be visualized directly or imaged on a micro-CT (µCT) scanner. When performed successfully, one can appreciate the pulmonary arterial network in mice ranging from early postnatal ages to adults. Additionally, while demonstrated in the pulmonary arterial bed, this method can be applied to any vascular bed with optimized catheter placement and endpoints.

Background: Pesticide exposure during susceptible windows and at certain doses are linked to numerous birth defects. Early experimental evidence suggests an association between active ingredients in pesticides and holoprosencephaly (HPE), the most common malformation of the forebrain in humans (1 in 250 embryos). No human studies to date have examined the association. This study investigated pesticides during multiple windows of exposure and fetal risk for HPE. It is hypothesized that pre-conception and early pregnancy, the time of brain development in utero, are the most critical windows of exposure., Methods: A questionnaire was developed for this retrospective case-control study to estimate household, occupational, and environmental pesticide exposures. Four windows of exposure were considered: preconception, early, mid and late pregnancy. Cases were identified through the National Human Genome Research Institute's ongoing clinical studies of HPE. Similarly, controls were identified as children with Williams-Beuren syndrome, a genetic syndrome also characterized by congenital malformations, but etiologically unrelated to HPE. We assessed for differences in odds of exposures to pesticides between cases and controls., Results: Findings from 91 cases and 56 controls showed an increased risk for HPE with reports of maternal exposure during pregnancy to select pesticides including personal insect repellants (adjusted odds ratio (aOR) 2.89, confidence interval (CI): 0.96-9.50) and insecticides and acaricides for pets (aOR 3.84, CI:1.04-16.32). Exposure to household pest control products during the preconception period or during pregnancy was associated with increased risk for HPE (aOR 2.60, OR: 0.84-8.68). No associations were found for occupational exposures to pesticides during pregnancy (aOR: 1.15, CI: 0.11-11.42), although exposure rates were low. Higher likelihood for HPE was also observed with residency next to an agricultural field (aOR 3.24, CI: 0.94-12.31)., Conclusions: Observational findings are consistent with experimental evidence and suggest that exposure to personal, household, and agricultural pesticides during pregnancy may increase risk for HPE. Further investigations of gene by environment interactions are warranted.

Purpose of Review: Elastin has historically been described as an amorphous protein that functions to provide recoil to tissues that stretch. However, evidence is growing that elastin's role may not be limited to biomechanics. In this minireview, we will summarize current knowledge regarding vascular elastic fibers, focusing on structural differences along the arterial tree and how those differences may influence the behavior of affiliated cells., Recent Findings: Regional heterogeneity, including differences in elastic lamellar number, density and cell developmental origin, plays an important role in vessel health and function. These differences impact cell-cell communication, proliferation and movement. Perturbations of normal cell-matrix interactions are correlated with human diseases including aneurysm, atherosclerosis and hypertension., Summary: Although classically described as a structural protein, recent data suggest that differences in elastin deposition along the arterial tree have important effects on heterotypic cell interactions and human disease.

Williams-Beuren syndrome (WBS) is a multisystem disorder caused by a hemizygous deletion on 7q11.23 encompassing 26-28 genes. An estimated 2-5% of patients have "atypical" deletions, which extend in the centromeric and/or telomeric direction from the WBS critical region. To elucidate clinical differentiators among these deletion types, we evaluated 10 individuals with atypical deletions in our cohort and 17 individuals with similarly classified deletions previously described in the literature. Larger deletions in either direction often led to more severe developmental delays, while deletions containing MAGI2 were associated with infantile spasms and seizures in patients. In addition, head size was notably smaller in those with centromeric deletions including AUTS2. Because children with atypical deletions were noted to be less socially engaged, we additionally sought to determine how atypical deletions relate to social phenotypes. Using the Social Responsiveness Scale-2, raters scored individuals with atypical deletions as having different social characteristics to those with typical WBS deletions (p = .001), with higher (more impaired) scores for social motivation (p = .005) in the atypical deletion group. In recognizing these distinctions, physicians can better identify patients, including those who may already carry a clinical or FISH WBS diagnosis, who may benefit from additional molecular evaluation, screening, and therapy. In addition to the clinical findings, we note mild endocrine findings distinct from those typically seen in WBS in several patients with telomeric deletions that included POR. Further study in additional telomeric deletion cases will be needed to confirm this observation., (Published 2020. This article is a U.S. Government work and is in the public domain in the USA.)

Objective: To investigate the effect of somatic, postzygotic, gain-of-function mutation of Endothelial Per-Arnt-Sim (PAS) domain protein 1 ( EPAS1 ) encoding hypoxia-inducible factor-2α (HIF-2α) on posterior fossa development and spinal dysraphism in EPAS1 gain-of-function syndrome, which consists of multiple paragangliomas, somatostatinoma, and polycythemia., Methods: Patients referred to our institution for evaluation of new, recurrent, and/or metastatic paragangliomas/pheochromocytoma were confirmed for EPAS1 gain-of-function syndrome by identification of the EPAS1 gain-of-function mutation in resected tumors and/or circulating leukocytes. The posterior fossa, its contents, and the spine were evaluated retrospectively on available MRI and CT images of the head and neck performed for tumor staging and restaging. The transgenic mouse model underwent Microfil vascular perfusion and subsequent intact ex vivo 14T MRI and micro-CT as well as gross dissection, histology, and immunohistochemistry to assess the role of EPAS1 in identified malformations., Results: All 8 patients with EPAS1 gain-of-function syndrome demonstrated incidental posterior fossa malformations-one Dandy-Walker variant and 7 Chiari malformations without syringomyelia. These findings were not associated with a small posterior fossa; rather, the posterior fossa volume exceeded that of its neural contents. Seven of 8 patients demonstrated spinal dysraphism; 4 of 8 demonstrated abnormal vertebral segmentation. The mouse model similarly demonstrated features of neuraxial dysraphism, including cervical myelomeningocele and spinal dysraphism, and cerebellar tonsil displacement through the foramen magnum. Histology and immunohistochemistry demonstrated incomplete mesenchymal transition in the mutant but not the control mouse., Conclusions: This study characterized posterior fossa and spinal malformations seen in EPAS1 gain-of-function syndrome and suggests that gain-of-function mutation in HIF-2α results in improper mesenchymal transition., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To evaluate the occurrence and estimate the frequency of macrocytosis in Williams-Beuren syndrome (WBS)., Study Design: Complete blood count (CBC) data from 179 subjects with WBS aged 1-69 were collected, with common parameters assessed for trends. Z-transformed mean corpuscular volume (MCV) was compared with each laboratory's reference range as well as with control data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 data archives., Results: Just over a third (35%) subjects had at least one recorded incidence of macrocytosis. In comparisons of CBC parameters with an expected population mean, MCV and MCH were greater than, while Hct and RDW were lower than, expected values. The distribution of erythrocyte MCV is shifted to the right in WBS compared to controls, as was the mean value. Despite this, anemia was absent, except in a single medically complex WBS subject. Though there was a paucity of data available of variables that could potentially cause an elevated MCV, no obvious etiology could be elucidated., Conclusions: Mild macrocytosis without anemia affects a moderate subset of WBS patients, leading to a rightward shift in the MCV distribution curve. Providers encountering isolated mild macrocytosis in WBS can consider observation over further workup., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Studies over the years have described a filamentous structure to mature elastin that suggests a complicated packing arrangement of tropoelastin subunits. The currently accepted mechanism for tropoelastin assembly requires microfibrils to serve as a physical extracellular scaffold for alignment of tropoelastin monomers during and before crosslinking. However, recent evidence suggests that the initial stages of tropoelastin assembly occur within the cell or at unique assembly sites on the plasma membrane where tropoelastin self assembles to form elastin aggregates. Outside the cell, elastin aggregates transfer to growing elastic fibers in the extracellular matrix where tensional forces on microfibrils generated through cell movement help shape the growing fiber. Overall, these observations challenge the widely held idea that interaction between monomeric tropoelastin and microfibrils is a requirement for elastin assembly, and point to self-assembly of tropoelastin as a driving force in elastin maturation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Identification of patients with cancer predisposition syndromes (CPSs) can provide vital information to guide care of an existing cancer, survey for future malignancy, and counsel families. The same underlying mutation responsible for a CPS may also result in other phenotypic abnormalities amenable to therapeutic intervention. The purpose of this study was to examine patients followed in our multidisciplinary CPS clinic to determine the prevalence and scope of medical and psychosocial needs. Data from a baseline evaluation of a single-center patient registry was reviewed. Eligible patients included those with a known or suspected CPS. Over 3 years, 73 patients consented and had successful follow-up. Utilization rate of special therapies, defined as speech therapy, occupational therapy, and/or physical therapy, in the CPS population was 50.7%, significantly higher than a representative sample of children with special needs. Prevalence of 504/IEP (Individualized Education Program) utilization was 20.5%. Patients with CPSs have a high prevalence of medical and psychosocial needs beyond their risk for cancer, for which early screening for necessary interventions should be offered to maximize the patient's developmental potential. Future research is needed to further define the developmental and cognitive phenotypes of these syndromes, and to evaluate the effectiveness of subsequent interventions.

Elastic fibers provide recoil to tissues that undergo repeated deformation, such as blood vessels, lungs and skin. Composed of elastin and its accessory proteins, the fibers are produced within a restricted developmental window and are stable for decades. Their eventual breakdown is associated with a loss of tissue resiliency and aging. Rare alteration of the elastin (ELN) gene produces disease by impacting protein dosage (supravalvar aortic stenosis, Williams Beuren syndrome and Williams Beuren region duplication syndrome) and protein function (autosomal dominant cutis laxa). This review highlights aspects of the elastin molecule and its assembly process that contribute to human disease and also discusses potential therapies aimed at treating diseases of elastin insufficiency., (Copyright © 2017. Published by Elsevier B.V.)

Background: Large, multigenic deletions at chromosome 7q11.23 result in a highly penetrant constellation of physical and behavioral symptoms known as Williams-Beuren syndrome (WS). Of particular interest is the unusual social-cognitive profile evidenced by deficits in social cognition and communication reminiscent of autism spectrum disorders (ASD) that are juxtaposed with normal or even relatively enhanced social motivation. Interestingly, duplications in the same region also result in ASD-like phenotypes as well as social phobias. Thus, the region clearly regulates human social motivation and behavior, yet the relevant gene(s) have not been definitively identified., Method: Here, we deeply phenotyped 85 individuals with WS and used exome sequencing to analyze common and rare variation for association with the remaining variance in social behavior as assessed by the Social Responsiveness Scale., Results: We replicated the previously reported unusual juxtaposition of behavioral symptoms in this new patient collection, but we did not find any new alleles of large effect in the targeted analysis of the remaining copy of genes in the Williams syndrome critical region. However, we report on two nominally significant SNPs in two genes that have been implicated in the cognitive and social phenotypes of Williams syndrome, BAZ1B and GTF2IRD1. Secondary discovery driven explorations focusing on known ASD genes and an exome wide scan do not highlight any variants of a large effect., Conclusions: Whole exome sequencing of 85 individuals with WS did not support the hypothesis that there are variants of large effect within the remaining Williams syndrome critical region that contribute to the social phenotype. This deeply phenotyped and genotyped patient cohort with a defined mutation provides the opportunity for similar analyses focusing on noncoding variation and/or other phenotypic domains., (© 2018 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Increased vascular stiffness correlates with a higher risk of cardiovascular complications in aging adults. Elastin (ELN) insufficiency, as observed in patients with Williams-Beuren syndrome or with familial supravalvular aortic stenosis, also increases vascular stiffness and leads to arterial narrowing. We used Eln +/- mice to test the hypothesis that pathologically increased vascular stiffness with concomitant arterial narrowing leads to decreased blood flow to end organs such as the brain. We also hypothesized that drugs that remodel arteries and increase lumen diameter would improve flow. To test these hypotheses, we compared carotid blood flow using ultrasound and cerebral blood flow using MRI-based arterial spin labeling in wild-type (WT) and Eln +/- mice. We then studied how minoxidil, an ATP-sensitive K + channel opener and vasodilator, affects vessel mechanics, blood flow, and gene expression. Both carotid and cerebral blood flows were lower in Eln +/- mice than in WT mice. Treatment of Eln +/- mice with minoxidil lowered blood pressure and reduced functional arterial stiffness to WT levels. Minoxidil also improved arterial diameter and restored carotid and cerebral blood flows in Eln +/- mice. The beneficial effects persisted for weeks after drug removal. RNA-Seq analysis revealed differential expression of 127 extracellular matrix-related genes among the treatment groups. These results indicate that ELN insufficiency impairs end-organ perfusion, which may contribute to the increased cardiovascular risk. Minoxidil, despite lowering blood pressure, improves end-organ perfusion. Changes in matrix gene expression and persistence of treatment effects after drug withdrawal suggest arterial remodeling. Such remodeling may benefit patients with genetic or age-dependent ELN insufficiency. NEW & NOTEWORTHY Our work with a model of chronic vascular stiffness, the elastin ( Eln) +/- mouse, shows reduced brain perfusion as measured by carotid ultrasound and MRI arterial spin labeling. Vessel caliber, functional stiffness, and blood flow improved with minoxidil. The ATP-sensitive K + channel opener increased Eln gene expression and altered 126 other matrix-associated genes.

Peroxisomal biogenesis disorders are caused by disruption of long chain fatty acid metabolism due to mutations in PEX genes. Individuals with these disorders often have vision loss due to optic atrophy and pigmentary retinopathy. We report an unusual retinal manifestation of peroxisomal biogenesis disorder.

Williams-Beuren syndrome (WBS) is a common microdeletion syndrome characterized by a 1.5Mb deletion in 7q11.23. The phenotype of WBS has been well described in populations of European descent with not as much attention given to other ethnicities. In this study, individuals with WBS from diverse populations were assessed clinically and by facial analysis technology. Clinical data and images from 137 individuals with WBS were found in 19 countries with an average age of 11 years and female gender of 45%. The most common clinical phenotype elements were periorbital fullness and intellectual disability which were present in greater than 90% of our cohort. Additionally, 75% or greater of all individuals with WBS had malar flattening, long philtrum, wide mouth, and small jaw. Using facial analysis technology, we compared 286 Asian, African, Caucasian, and Latin American individuals with WBS with 286 gender and age matched controls and found that the accuracy to discriminate between WBS and controls was 0.90 when the entire cohort was evaluated concurrently. The test accuracy of the facial recognition technology increased significantly when the cohort was analyzed by specific ethnic population (P-value < 0.001 for all comparisons), with accuracies for Caucasian, African, Asian, and Latin American groups of 0.92, 0.96, 0.92, and 0.93, respectively. In summary, we present consistent clinical findings from global populations with WBS and demonstrate how facial analysis technology can support clinicians in making accurate WBS diagnoses., (© 2018 Wiley Periodicals, Inc.)

Purpose: Evaluation of the clinician's role in the optimal interpretation of clinical exome sequencing (ES) results., Methods: Retrospective chart review of the first 155 patients who underwent clinical ES in our Exome Clinic and direct interaction with the ordering geneticist to evaluate the process of interpretation of results., Results: The most common primary indication was neurodevelopmental problems (~66%), followed by multiple congenital anomalies (~10%). Based on sequencing data, the overall diagnostic yield was 36%. After assessment by the medical geneticist, incorporation of detailed phenotypic and molecular data, and utilization of additional diagnostic modalities, the final diagnostic yield increased to 43%. Seven patients in our cohort were included in initial case series that described novel genetic syndromes, and 23% of patients were involved in subsequent research studies directly related to their results or involved in efforts to move beyond clinical ES for diagnosis. Clinical management was directly altered due to the ES findings in 12% of definitively diagnosed cases., Conclusions: Our results emphasize the usefulness of ES, demonstrate the significant role of the medical geneticist in the diagnostic process of patients undergoing ES, and illustrate the benefits of postanalytical diagnostic work-up in solving the "diagnostic odyssey." Genet Med advance online publication 02 March 2017.