Elastin is a connective tissue protein, produced from the ELN gene, that provides elasticity and recoil to tissues that stretch, such as the large arteries of the body, lung parenchyma, skin, ligaments and elastic cartilages. It is produced as a soluble monomer, tropoelastin, that when cross-linked in the extracellular space generates a polymer that is extraordinarily stable, with a predicted half-life of >70 years. Although data suggest ongoing elastin transcription, it is rare to see new elastin deposited outside of its tight developmental window. Consequently, elastin-related disease comes about primarily in one of three scenarios: (1) inadequate elastin deposition, (2) production of poor-quality elastic fibers, or (3) increased destruction of previously deposited elastin. By understanding the pathways controlling elastin production and maintenance, we can design new therapeutics to thwart those abnormal processes. In this review, we will summarize the diseases arising from genetic and environmental alteration of elastin (Williams syndrome, supravalvar aortic stenosis, autosomal dominant cutis laxa, and ELN-related vascular and connective tissue dysfunction) and then describe the mechanisms controlling elastin production and maintenance that might be manipulated to generate novel therapeutics aimed at these conditions. We will end by summarizing existing therapeutic strategies targeting these disease mechanisms before outlining future approaches that may better solve the challenges associated with elastin based regenerative medicine.

Williams syndrome is caused by a microdeletion of genes on chromosome 7q11.23. It is estimated that 75% of individuals with Williams syndrome meet criteria for intellectual disability. The existing literature, primarily using the Differential Ability Scales, supports a pattern of relative weakness in visuospatial construction and language abilities commensurate with or slightly stronger than overall cognitive functioning. However, it is unclear how cognitive profile patterns are captured by current versions of the Wechsler system of assessment, which is more commonly used in community settings. Further, few longitudinal data on cognitive profiles exist, limiting conclusions about developmental trends. The current study included 59 individuals with Williams syndrome aged 4-24 years assessed with the age-appropriate Wechsler test a median of twice over 3 ± 1.5 years. The results of this study confirmed the profile found in the extant literature, but there was evidence of heterogeneity in relative strengths and weaknesses that necessitates individual evaluation. Careful longitudinal modeling of between- and within-person effects suggested stability of standard scores in all domains. The results of this study inform a developmental understanding of the Williams syndrome cognitive profile and improve the interpretability of research findings for clinical and school settings where the Wechsler system is commonly used.

BACKGROUND:Ibrutinib (IBR) is a first-in-class Bruton's tyrosine kinase inhibitor (BTKi) approved in multiple hematologic conditions for indefinite use until disease progression or toxicity. Hypertension and atrial fibrillation are well-recognized cardiac complications of BTKi; more recently, heart failure, additional arrhythmias, and sudden cardiac death (SCD) have been attributed to IBR. Next-generation covalent BTKi are also associated with cardiovascular complications, including SCD, albeit to a lesser degree. OBJECTIVE:The incidence and clinical features of patients experiencing SCD and asymptomatic arrhythmias on IBR remain ill defined. We aimed to characterize the incidence of SCD and asymptomatic arrhythmias on IBR. METHODS:We report (1) a retrospective cohort analysis of 131 patients with a median of 66.5 months on IBR using available cardiac testing, genetic sequencing, and autopsy review and (2) a cross-sectional cardiac analysis of 21 asymptomatic patients on IBR including ambulatory electrocardiogram, stress tests, and transthoracic echocardiograms. RESULTS:The incidence of SCD in patients on IBR (n = 5) was 801 per 100,000 patient-years, approximately 2-4× higher than the general population. All patients with SCD on IBR had at least 1 cardiac risk factor. Autopsies conducted in 3 of 5 patients with SCD did not reveal acute pathologic processes, but did demonstrate evolving cardiac pathology. Cardiovascular testing in asymptomatic patients on IBR revealed previously unknown clinically significant arrhythmias in 4 patients (19%), leading to precautionary IBR discontinuation in 2 patients. CONCLUSION:IBR increases the risk of SCD among patients with cardiac risk factors. Stress and ambulatory electrocardiogram on IBR identified asymptomatic arrhythmias altering clinical management in 19% of patients. These data highlight the need for risk-mitigation strategies for patients starting or receiving IBR, possibly extending to other BTKis.

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 <2.8x10-5) 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.

Background: Head and neck paragangliomas (HNPGLs) are typically slow-growing, hormonally inactive tumors of parasympathetic paraganglia. Inactivation of prolyl-hydroxylase domain-containing 2 protein causing indirect gain-of-function of hypoxia-inducible factor-2 alpha (HIF-2 alpha), encoded by EPAS1, was recently shown to cause carotid body hyperplasia. We previously described a syndrome with multiple sympathetic paragangliomas caused by direct gain-of-function variants in EPAS1 (Pacak-Zhuang syndrome, PZS) and developed a corresponding mouse model. Methods: We evaluated a cohort of patients with PZS (n 1/4 9) for HNPGL by positron emission tomography, magnetic resonance imaging, and computed tomography and measured carotid body size compared to literature reference values. Resected tumors were evaluated by histologic sectioning and staining. We evaluated the corresponding mouse model at multiple developmental stages (P8 and adult) for lesions of the head and neck by high resolution ex vivo imaging and performed immunohistochemical staining on histologic sections of the identified lesions. Results: hree patients had imaging consistent with HNPGL, one of which warranted resection and was confirmed on histology. Three additional patients had carotid body enlargement (Z-score > 2.0), and 3 had carotid artery malformations. We found that 9 of 10 adult variant mice had carotid body tumors and 6 of 8 had a paraganglioma on the cranio-caval vein, the murine homologue of the superior vena cava; these were also found in 4 of 5 variant mice at post-natal day 8. These tumors and the one resected from a patient were positive for tyrosine hydroxylase, synaptophysin, and chromogranin A. Brown fat in a resected patient tumor carried the EPAS1 pathogenic variant. Conclusions: These findings (1) suggest HNPGL as a feature of PZS and (2) show that these pathogenic variants are sufficient to cause the development of these tumors, which we believe represents a continuous spectrum of disease starting from hyperplasia.

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.

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.

Aging is an immutable risk factor for the development of numerous cardiovascular diseases, including vascular dementia. Vascular dementia is the second most common cause of dementia with up to 20% of dementia cases in the elderly attributed to dysfunctional vasculature. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), is a mendelian vascular dementia characterized by progressive dysfunction of vascular smooth muscle cells (vSMCs) due to gene variants in NOTCH3 . With over 250 known disease - causing variants in NOTCH3 identified in the past 24 years, the allelic heterogeneity observed in CADASIL has long contributed to our impaired understanding of the molecular progression from NOTCH3 variation to clinical presentation. Recent work published by our group has shown that Notch3 is lost from in the cerebral vasculature of mouse ( Notch3 -/- ) and humans during aging. With time, the progressive loss of Notch3 in the aging mouse brain vasculature drives the formation of cerebral micro-aneurysms as well as impairs vascular reactivity and cerebral blood flow. These vascular consequences also hinder glymphatic flow which promotes an accelerated aggregation of glycosaminoglycans and the development of neuronal gene signature analogous to those observed in other neurodegenerative diseases such as Alzheimer’s disease. To assess if CADASIL represents a loss of NOTCH3 function and thus an accelerated cerebral aging or novel gain of function in NOTCH3, we used CRISPR-Cas9 genome editing to create a novel CADASIL mouse model: Notch3C175Y (N3Y). This alteration faithfully recapitulates the human variant within the same locus and shows the pathological hallmark of CADASIL: GOMs (granular osmiophilic material). Histopathological assessment of the N3Y mouse shows dysregulation of the vSMC organization as early as 8 weeks of age along with novel structural abnormalities as compared to the Notch3 -/- . Using single-cell RNA sequencing we also performed in-depth molecular characterization of the vascular changes in N3Y. Analysis at 2 months and at 24 months allowed us to identify temporal progression of the disease and provided novel molecular insights into the mechanisms of this mendelian form of vascular dementia.

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.

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.

Williams syndrome (WS) is caused by a hemizygous deletion of 1.5-1.8 Mb of chromosome 7q11.23. People with this condition exhibit great vessel discrete and long segment stenosis in the setting of a variety of other developmental and medical features. In WS, deletion of the elastin gene (ELN) results in the associated vascular phenotypes including, but not limited to, supravalvar aortic stenosis (SVAS), supravalvar pulmonic stenosis (SVPS), and branch pulmonary artery (PA) stenosis. While genetic modifiers of SVAS severity have been described, it is unclear whether pulmonary vascular outcomes are modified by the same gene variants.

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.

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.

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.

Genetic disorders are complex and can greatly impact an individual's health and well-being. In this study, we assess the ability of ChatGPT, a language model developed by OpenAI, to answer questions related to three specific genetic disorders: BRCA1, MLH1, and HFE. ChatGPT has shown it can supply articulate answers to a wide spectrum of questions. However, its ability to answer questions related to genetic disorders has yet to be evaluated. The aim of this study is to perform both quantitative and qualitative assessments of ChatGPT's performance in this area. The ability of ChatGPT to provide accurate and useful information to patients was assessed by genetic experts. Here we show that ChatGPT answered 64.7% of the 68 genetic questions asked and was able to respond coherently to complex questions related to the three genes/conditions. Our results reveal that ChatGPT can provide valuable information to individuals seeking information about genetic disorders, however, it still has some limitations and inaccuracies, particularly in understanding human inheritance patterns. The results of this study have implications for both genomics and medicine and can inform future developments in this area. AI platforms, like ChatGPT, have significant potential in the field of genomics. As these technologies become integrated into consumer-facing products, appropriate oversight is required to ensure accurate and safe delivery of medical information. With such oversight and training specifically for genetic information, these platforms could have the potential to augment some clinical interactions.

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 Poincare plot (SD1) [P < 0.0001], and long axis of the Poincare plot [P < 0.0001]) and indirect markers of parasym-pathetic 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 Poincare 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) (J Am Coll Cardiol EP 2023;9:359-37 0) Published by Elsevier on behalf of the American College of Cardiology Foundation.

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