Williams Syndrome Research Articles

Williams–Beuren Syndrome in Adulthood for Hernia Repair: Anesthetic Challenges and Tutorial on Atrial Fibrillation

Williams–Beuren Syndrome in Adulthood for Hernia Repair: Anesthetic Challenges and Tutorial on Atrial Fibrillation

Developmental characteristics of Williams-Beuren syndrome and evaluation of adaptive behavioral skills.

Williams-Beuren syndrome (WBS) is a rare genetic disorder with delays in language and cognitive development, but, with increased awareness of clinical features and a reliable diagnostic test, WBS is becoming more widely recognized in childhood. Adaptive behavior skills and/or maladaptive behavior are important for the prognosis of individuals with WBS. The aim of this study was to investigate the clinical and developmental characteristics of patients with WBS and further increase awareness about it by evaluating the adaptive skills and maladaptive behaviors of the patients. The data of WBS patients followed-up at the Developmental Behavioral Pediatrics Unit were reviewed. Patient data on perinatal and postnatal history, developmental stages, physical and neurological examination findings were collected. The International Guide for Monitoring Child Development (GMCD) was administered to each child. In addition, semistructured interviews were conducted with the parents using the Vineland Adaptive Behavior Scales, Second edition (Vineland-II). A total of 12 patients diagnosed with WBS via detection of the 7q11.23 deletion, of whom 6 were girls, were retrospectively reviewed. The mean age at the time of review was 54.6 ± 32.5 months. The mean age at first presentation to the Developmental Behavioral Pediatrics Outpatient Clinic was 15 ± 11.5 months. In the first developmental evaluation using the GMCD, there was a delay in fine and gross motor domains in 6 patients, in the language domains in 4 patients, and in all of the domains in 2 patients. Findings with Vineland-II showed socialization and communication domains as strengths, but the daily living skills and motor skills domains were weaknesses. In terms of maladaptive behavior, the patients tended to frequently have behavioral problems, neurodevelopmental disease, anxiety disorders, eating problems, and sleeping problems. This retrospective review of 12 patients indicated a general delay in overall development, and confirmed impairment in both adaptive and maladaptive functioning in WBS.

No transfer of arousal from other’s eyes in Williams syndrome

Typically developing humans automatically synchronize their arousal levels, resulting in pupillary contagion, or spontaneous adaptation of pupil size to that of others. This phenomenon emerges in infancy and is believed to facilitate social interaction. Williams syndrome (WS) is a genetic condition characterized by a hyper-social personality and social interaction challenges. Pupillary contagion was examined in individuals with WS (n = 44), age-parallel-matched typically developing children and adults (n = 65), and infants (n = 79). Bayesian statistics were used. As a group, people with WS did not show pupillary contagion (Bayes factors supporting the null: 25–50) whereas control groups did. This suggests a very early emerging atypical developmental trajectory. In WS, higher pupillary contagion was associated with lower autistic symptoms of social communication. Diminished synchronization of arousal may explain why individuals with WS have social challenges, whereas synchronization of arousal is not a necessary correlate of high social motivation.

Intensive Care Unit Analgosedation After Cardiac Surgery in Children with Williams Syndrome : a Matched Case-Control Study.

Cardiovascular abnormalities are common in patients with Williams syndrome and frequently require surgical intervention necessitating analgesia and sedation in a population with a unique neuropsychiatric profile, potentially increasing the risk of adverse cardiac events during the perioperative period. Despite this risk, the overall postoperative analgosedative requirements in patients with WS in the cardiac intensive care unit have not yet been investigated. Our primary aim was to examine the analgosedative requirement in patients with WS after cardiac surgery compared to a control group. Our secondary aim was to compare the frequency of major ACE and mortality between the two groups. Matched case-control study. Pediatric CICU at a Tertiary Children's Hospital. Patients with WS and age-matched controls who underwent cardiac surgery and were admitted to the CICU after cardiac surgery between July 2014 and January 2021. None. Postoperative outcomes and total doses of analgosedative medications were collected in the first six days after surgery for the study groups. Median age was 29.8 (12.4-70.8) months for WS and 23.5 (11.2-42.3) months for controls. Across all study intervals (48h and first 6 postoperative days), there were no differences between groups in total doses of morphine equivalents (5.0mg/kg vs 5.6mg/kg, p = 0.7 and 8.2mg/kg vs 10.0mg/kg, p = 0.7), midazolam equivalents (1.8mg/kg vs 1.5mg/kg, p = 0.4 and 3.4mg/kg vs 3.8mg/kg, p = 0.4), or dexmedetomidine (20.5 mcg/kg vs 24.4 mcg/kg, p = 0.5 and 42.3 mcg/kg vs 39.1 mcg/kg, p = 0.3). There was no difference in frequency of major ACE or mortality. Patients with WS received similar analgosedative medication doses compared with controls. There was no significant difference in the frequency of major ACE (including cardiac arrest, extracorporeal membrane oxygenation, and surgical re-intervention) or mortality between the two groups, though these findings must be interpreted with caution. Further investigation is necessary to elucidate the adequacy of pain/sedation control, factors that might affect analgosedative needs in this unique population, and the impact on clinical outcomes.

Internalising and Externalising Symptoms and Their Association with the Family Environment in Young Children with Williams Syndrome: A Longitudinal Study.

Williams Syndrome (WS) involves high rates of psychopathology across the lifespan. However, little is known about the early, longitudinal trajectory of internalising/externalising symptoms or the association between these and the family environment in WS. WS (n = 16; aged 2 years, 2 months to 9 years, 5 months) and typically developing or TD (n = 46; aged 2 years, 2 months to 11 years, 1 month) children were assessed on two occasions over 2.5 years utilising parent report questionnaires-the Child Behaviour Checklist and the Family Environment Scale. No statistically significant changes were found in CBCL/psychopathology profiles across timepoints, on average, for either WS or TD children. However, reliable change scores showed WS children had considerable variability in CBCL scores over time. Cross-sectionally, the WS group showed higher scores (reflecting more psychopathology) compared to TD controls at both time points across most CBCL subscales, with elevated overall psychopathology problems identified in 56-68% of WS children (versus 8% in TD controls). Psychopathology was not associated with sex, chronological age, or cognitive ability in WS. Conflict in the family environment was positively associated with higher Attention Problems at Time 1 in the WS group, whilst the TD group showed associations between family conflict and total psychopathology problems at both time points and between family cohesion and total psychopathology problems at Time 2. Family environment did not differ between groups, except for lower engagement in intellectual and cultural activities in WS. Findings highlight variable Internalising and Externalising Problems in young WS children over time, with greater biological than environmental contributions to psychopathology in WS.

Loss of Baz1b in mice causes perinatal lethality, growth failure, and variable multi-system outcomes

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.

17.2 Symptomatic and Mechanism-Based Treatments for Neuropsychiatric Symptoms in Williams Syndrome

17.2 Symptomatic and Mechanism-Based Treatments for Neuropsychiatric Symptoms in Williams Syndrome

S2310 Ischemic Colitis in Williams Syndrome: A Case of a Rare Complication of a Rare Disease

S2310 Ischemic Colitis in Williams Syndrome: A Case of a Rare Complication of a Rare Disease

Clinical heterogeneity and therapeutic options foridiopathic infantile hypercalcemia caused byCYP24A1 pathogenic variant.

Infantile hypercalcemia-1(HCINF1) is a rare disease caused by pathogenic variants in the CYP24A1 gene, resulting in the inability to metabolize active vitamin D. This leads to hypercalcemia and severe complications. On December 8th, 2022, a systematic literature search was conducted in PubMed, Wanfang, and CNKI usingthe keywords "hypercalcemia" and "CYP24A1". Data extraction included patient demographics, clinical presentation, treatment medications, and outcomes. The findings were synthesized to identify common patterns and variations among cases and to assess the efficacy of different therapies in reducing serum calcium. Our findings revealed two distinct peaks in the incidence of HCINF1 caused by CYP24A1 pathogenic variant. Kidney stones or renal calcifications were the most common clinical manifestations of the disease, followed by polyuria and developmental delay. Laboratory investigations showed hypercalcemia, elevated vitamin D levels, hypercalciuria, and low parathyroid hormone. Genetic analysis remains the only reliable diagnostic tool. Although there is no definitive cure for HCINF1, multiple drugs, including bisphosphonates, calcitonin, and rifampicin, have been used to control its symptoms. Blocking the production and intake of vitamin D is the preferred treatment option. Our review highlights the basic clinical and biochemical features of HCINF1 and suggests that targeted diagnostic and therapeutic strategies are needed to address the clinical heterogeneity of the disease. The insights gained from this study may facilitate the development of innovative treatments for HCINF1.

DNA methylation profiles in individuals with rare, atypical 7q11.23 CNVs correlate with GTF2I and GTF2IRD1 copy number

Williams-Beuren syndrome (WBS) and 7q11.23 duplication syndrome (Dup7) are rare neurodevelopmental disorders caused by deletion and duplication of a 1.5 Mb region that includes at least five genes with a known role in epigenetic regulation. We have shown that CNV of this chromosome segment causes dose-dependent, genome-wide changes in DNA methylation, but the specific genes driving these changes are unknown. We measured genome-wide whole blood DNA methylation in six participants with atypical CNV of 7q11.23 (three with deletions and three with duplications) using the Illumina HumanMethylation450k array and compared their profiles with those from groups of individuals with classic WBS or classic Dup7 and with typically developing (TD) controls. Across the top 1000 most variable positions we found that only the atypical rearrangements that changed the copy number of GTF2IRD1 and/or GTF2I (coding for the TFII-IRD1 and TFII-I proteins) clustered with their respective syndromic cohorts. This finding was supported by results from hierarchical clustering across a selection of differentially methylated CpGs, in addition to pyrosequencing validation. These findings suggest that CNV of the GTF2I genes at the telomeric end of the 7q11.23 interval is a key contributor to the large changes in DNA methylation that are seen in blood DNA from our WBS and Dup7 cohorts, compared to TD controls. Our findings suggest that members of the TFII-I protein family are involved in epigenetic processes that alter DNA methylation on a genome-wide level.

Multisensory Texture Perception in Individuals with Williams Syndrome.

The sensory profile of people with Williams syndrome (WS) is characterised by atypical visual and auditory perceptions that affect their daily lives and learning. However, no research has been carried out on the haptic perception, in particular in multisensory (visual and haptic) situations. The aim of this study was to evaluate the communication of texture information from one modality to the other in people with WS. Children and adults with WS were included, as well as typically developing (TD) participants matched on chronological age (TD-CA), and TD children matched on mental age (TD-MA). All participants (N = 69) completed three matching tasks in which they had to compare two fabrics (same or different): visual, haptic and visuo-haptic. When the textures were different, the haptic and visual performances of people with WS were similar to those of TD-MA participants. Moreover, their visuo-haptic performances were lower than those of the two TD groups. These results suggest a delay in the acquisition of multisensory transfer abilities in individuals with WS. A positive link between MA and visual and visuo-haptic abilities only in people with WS suggests that they could benefit from an early intervention to develop their abilities to process and transfer multisensory information.

Parental attitudes and beliefs about sexuality of individuals with intellectual disability: Insights from a Brazilian sample of parents of individuals with Williams syndrome.

The affective expression of sexual behaviour in individuals with Williams syndrome can lead to risky behaviours, especially if parents do not have information on how to provide sex education or support from specialised professionals. The Attitudes to Sexuality Questionnaire for Individuals with Intellectual Disabilities was used to identify parental beliefs, attitudes and concerns about the sexuality and sex education of individuals with intellectual disabilities. The sample comprised 35 parents of individuals with Williams syndrome (mean age 12.8 years (SD = 4.5), 57.1% male). Parents believe in the possibility of marriage and sexual relationships for individuals with intellectual disability when they are older and agree with sexual reproduction in adulthood. Parents consider that sex education, in addition to parental guidance, should be provided by professionals. This data highlights the need for parents to have clear guidelines on interventions in respect of the sexuality of individuals with intellectual disability.

Appreciation of Slapstick Humour and Expressivity in Response to Amusing Stimuli in Individuals with Williams Syndrome

ObjectivesPrevious studies on the comprehension and appreciation of humour in individuals with Williams syndrome (WS) have only included complex types of humour that required complex cognitive abilities. Additionally, although individuals with WS have been described as having a bias towards positive emotions, no study has investigated their expressive responses to humour.MethodsThe present study examined basic humour processing skills, as well as expressive responses to simple humorous and non-humorous stimuli in individuals with WS (N = 8) compared to mental-age matched typically developing (TD) children (N = 9). Participants were shown short funny and non-funny excerpts of the movies “Ice Age” and “Madagascar” and were asked to rate their level of amusement. Their expressive responses, namely smiles and laughs, were coded and analysed.ResultsIndividuals with WS seem to be able to discriminate between humorous and non-humorous conditions and appreciate simple humorous content as much as TD individuals. As such, they are equally able to process simple types of humour as their mental-age matched counterparts. Additionally, and in line with their positivity bias, individuals with WS expressed more frequent and more intense laughter than the control group.ConclusionIndividuals with WS appreciate simple humour as much as TD individuals, and they seem to display a particularly high expressivity in response to humorous stimuli.

Dorsal visual stream and LIMK1: hemideletion, haplotype, and enduring effects in children with Williams syndrome

BackgroundWilliams syndrome (WS), a rare neurodevelopmental disorder caused by hemizygous deletion of ~ 25 genes from chromosomal band 7q11.23, affords an exceptional opportunity to study associations between a well-delineated genetic abnormality and a well-characterized neurobehavioral profile. Clinically, WS is typified by increased social drive (often termed “hypersociability”) and severe visuospatial construction deficits. Previous studies have linked visuospatial problems in WS with alterations in the dorsal visual processing stream. We investigated the impacts of hemideletion and haplotype variation of LIMK1, a gene hemideleted in WS and linked to neuronal maturation and migration, on the structure and function of the dorsal stream, specifically the intraparietal sulcus (IPS), a region known to be altered in adults with WS.MethodsWe tested for IPS structural and functional changes using longitudinal MRI in a developing cohort of children with WS (76 visits from 33 participants, compared to 280 visits from 94 typically developing age- and sex-matched participants) over the age range of 5–22. We also performed MRI studies of 12 individuals with rare, shorter hemideletions at 7q11.23, all of which included LIMK1. Finally, we tested for effects of LIMK1 variation on IPS structure and imputed LIMK1 expression in two independent cohorts of healthy individuals from the general population.ResultsIPS structural (p < 10−4 FDR corrected) and functional (p < .05 FDR corrected) anomalies previously reported in adults were confirmed in children with WS, and, consistent with an enduring genetic mechanism, were stable from early childhood into adulthood. In the short hemideletion cohort, IPS deficits similar to those in WS were found, although effect sizes were smaller than those found in WS for both structural and functional findings. Finally, in each of the two general population cohorts stratified by LIMK1 haplotype, IPS gray matter volume (pdiscovery < 0.05 SVC, preplication = 0.0015) and imputed LIMK1 expression (pdiscovery = 10−15, preplication = 10−23) varied according to LIMK1 haplotype.ConclusionsThis work offers insight into neurobiological and genetic mechanisms responsible for the WS phenotype and also more generally provides a striking example of the mechanisms by which genetic variation, acting by means of molecular effects on a neural intermediary, can influence human cognition and, in some cases, lead to neurocognitive disorders.

Beyond the conservative hypothesis: a meta-analysis of lexical-semantic processing in Williams syndrome – ERRATUM

Beyond the conservative hypothesis: a meta-analysis of lexical-semantic processing in Williams syndrome – ERRATUM

Ocular features in Williams-Beuren syndrome: a review of the literature.

The current review will discuss the pathophysiology, work-up and clinical relevance of the ocular phenotype in Williams-Beuren syndrome in detail. Few case reports, case series and retrospective studies reported the ophthalmic features in Williams-Beuren syndrome, focusing on specific aspects of the ocular involvement. Recently, novel retinal findings have been described in association with the disease. Numerous ocular features have been described in Williams-Beuren syndrome. Some of them, such as the stellate pattern of the iris or the retinal arteriolar tortuosity may be helpful for the diagnosis but have no significant clinical implications; others, such as strabismus and refractive errors require early treatment to reduce the risk of irreversible visual impairment. Finally, some features, such as a broad foveal pit and thinner retina still have unknown significance and require further longitudinal and multimodal studies.

Diversity of Participants in Williams Syndrome Intervention Studies.

This study describes participant diversity in Williams syndrome (WS) intervention studies. A literature search was conducted to identify prospective treatment studies including participants with WS. Data was extracted on the reporting of and information provided on age, sex, cognitive ability, socioeconomic status, race, and ethnicity. Eleven eligible articles were identified. Reporting rates of demographic factors varied considerably, with the highest rates for age and sex (100%) and the lowest reporting rates for race (18%) and ethnicity (9%). Combining demographic data from the two studies that reported on race and/or ethnicity (n = 33), 88% of participants were White. The combined participant mean age was 20.9 years. There is a low frequency of reporting on several demographic factors including socioeconomic status, race, and ethnicity in WS intervention studies. There is a need for increased representation of racial and ethnic minority groups, older participants, and more cognitively impaired patients in WS research.

Deletion of Gtf2i via Systemic Administration of AAV-PHP.eB Virus Increases Social Behavior in a Mouse Model of a Neurodevelopmental Disorder.

Williams syndrome (WS) is a neurodevelopmental disorder characterized by distinctive cognitive and personality profiles which also impacts various physiological systems. The syndrome arises from the deletion of about 25 genes located on chromosome 7q11.23, including Gtf2i. Prior research indicated a strong association between pre-natal Gtf2i deletion, and the hyper-social phenotypes observed in WS, as well as myelination deficits. As most studies addressed pre-natal Gtf2i deletion in mouse models, post-natal neuronal roles of Gtf2i were unknown. To investigate the impact of post-natal deletion of neuronal Gtf2i on hyper-sociability, we intravenously injected an AAV-PHP.eB virus expressing Cre-recombinase under the control of αCaMKII, a promoter in a mouse model with floxed Gtf2i. This targeted deletion was performed in young mice, allowing for precise and efficient brain-wide infection leading to the exclusive removal of Gtf2i from excitatory neurons. As a result of such gene deletion, the mice displayed hyper-sociability, increased anxiety, impaired cognition, and hyper-mobility, relative to controls. These findings highlight the potential of systemic viral manipulation as a gene-editing technique to modulate behavior-regulating genes during the post-natal stage, thus presenting novel therapeutic approaches for addressing neurodevelopmental dysfunction.

Dissociable Cognitive Systems for Recognizing Places and Navigating through Them: Developmental and Neuropsychological Evidence.

Recent neural evidence suggests that the human brain contains dissociable systems for "scene categorization" (i.e., recognizing a place as a particular kind of place, for example, a kitchen), including the parahippocampal place area, and "visually guided navigation" (e.g., finding our way through a kitchen, not running into the kitchen walls or banging into the kitchen table), including the occipital place area. However, converging behavioral data - for instance, whether scene categorization and visually guided navigation abilities develop along different timelines and whether there is differential breakdown under neurologic deficit - would provide even stronger support for this two-scene-systems hypothesis. Thus, here we tested scene categorization and visually guided navigation abilities in 131 typically developing children between 4 and 9 years of age, as well as 46 adults with Williams syndrome, a developmental disorder with known impairment on "action" tasks, yet relative sparing on "perception" tasks, in object processing. We found that (1) visually guided navigation is later to develop than scene categorization, and (2) Williams syndrome adults are impaired in visually guided navigation, but not scene categorization, relative to mental age-matched children. Together, these findings provide the first developmental and neuropsychological evidence for dissociable cognitive systems for recognizing places and navigating through them.SIGNIFICANCE STATEMENT Two decades ago, Milner and Goodale showed us that identifying objects and manipulating them involve distinct cognitive and neural systems. Recent neural evidence suggests that the same may be true of our interactions with our environment: identifying places and navigating through them are dissociable systems. Here we provide converging behavioral evidence supporting this two-scene-systems hypothesis - finding both differential development and breakdown of "scene categorization" and "visually guided navigation." This finding suggests that the division of labor between perception and action systems is a general organizing principle for the visual system, not just a principle of the object processing system in particular.

Abstract P3024: Endothelial To Mesenchymal Transition Frequency Increases In Williams Syndrome Pulmonary Artery Endothelial Cells In Novel 3D Bioprinted In Vitro Arterial Model

Introduction: Pulmonary artery stenosis (PAS) affects 1 in 2000 live births worldwide, with several causes, most commonly by genetic mutations that lead to or are associated with other congenital heart diseases (CHD). Despite its prevalence, long-term treatment strategies for patients with PAS remains ineffective due to its heterogenous etiology. In the last few decades, researchers have found hemodynamic forces to be a great contributor to stenosis development because it induces endothelial cell (EC) dysfunction through endothelial-to-mesenchymal transition (EndMT). Current pulmonary artery models, in vivo and in vitro , are ineffective in uncovering this mechanism in PAS because they either are unable to recapitulate the phenotype or the micromechanical environment. Methods: To address these limitations, we developed and optimized a high-throughput 3D bioprinted in vitro vascular model that recapitulates patient-specific disease states to determine how EndMT plays a role in stenosis development. This bioprinted model will be a cellularized bilayer comprised of EC and smooth muscle cells (SMC) sourced from either human primary cells or our established Williams Syndrome (WS) induced-pluripotent stem cell (iPSC) lines. WS was chosen due to its high predisposition in developing PAS, around 50%. Our hypothesis is that utilizing our 3D bioprinted model, we will demonstrate how alterations in hemodynamic forces, specifically flow regiments, will further promote EndMT in the WS group. Results: Encapsulated SMC functionality and differentiated phenotype was confirmed by calcium measurement and immunohistochemistry, respectively. Single-cell RNA sequencing (scRNA-seq) was used to examine EC, SMC, EC-SMC crosstalk, and EndMT gene expression profiles. Conclusion: This work represents a new and substantive departure from conventional in vitro vascular modeling, for it will allow us to identify initial vascular cellular responses in acute non-homeostatic conditions and uncover unique signaling pathways found in multiple CHD related PAS. This fundamental knowledge from our vascular mimics can then be applied to facilitate translational advancements in treatment of PAS via surgical and transcatheter intervention methods.