Presenting phenotype and clinical evaluation in a cohort of 22 Williams-Beuren syndrome patients

Noninvasive prenatal screening and diagnosis of two fetuses with Williams syndrome in a cohort of 19,607 pregnancies

BACKGROUND

This study aimed to evaluate the efficiency of noninvasive prenatal screening (NIPS) technology in screening for microdeletions in the 7q11.23 region.

METHODS

19,607 pregnant women underwent NIPS in our hospital. Maternal peripheral cell-free foetal DNA (cffDNA) was routinely screened for aneuploidy by cffDNA enrichment and simultaneously analyzed for pathogenic copy number variants (CNVs). The Williams syndrome (WS) 7q11.23 region was targeted in this study. Chromosomal microarray analysis (CMA) was used to verify the screen-positive samples.

RESULTS

The mean concentration of cffDNA before and after enrichment increased from 9.44% to 19.32%, with a statistically significant difference. Two out of 19,607 samples tested for CNVs were found to have a heterozygous deletion at the 7q11.23 region, indicating a high risk for WS. CMA results confirmed the 1.5 megabase (Mb) deletions at the 7q11.23 region in amniotic fluid samples. One of the two WS foetuses had a small left ventricle by ultrasound screening, and the other did not have a significant cardiovascular abnormality phenotype.

CONCLUSIONS

NIPS screening for Williams syndrome can be achieved by enriching cell-free foetal DNA and improving bioinformatic analysis algorithms.

Antenatal ultrasound features of isolated recurrent copy number variation in 7q11.23 (Williams syndrome and 7q11.23 duplication syndrome)

OBJECTIVE

We aimed to gather fetal cases carrying a 7q11.23 copy number variation (CNV) and collect precise clinical data to broaden knowledge of antenatal features in these syndromes.

METHODS

We retrospectively recruited unrelated cases with 7q11.23 deletion, known as Williams-Beuren syndrome (WBS), or 7q11.23 duplication who had prenatal ultrasound findings. We collected laboratory and clinical data, fetal ultrasound, cardiac ultrasound and fetal autopsy reports from 18 prenatal diagnostic centers throughout France.

RESULTS

40 fetuses with WBS were collected and the most common features were intra-uterine growth retardation (IUGR) (70.0%, 28/40), cardiovascular defects (30.0%, 12/40), polyhydramnios (17.5%, 7/40) and protruding tongue (15.0%, 6/40). Fetal autopsy reports were available for 11 cases and were compared with ultrasound prenatal features. Four cases of fetuses with 7q11.23 microduplication were collected and prenatal ultrasound signs were variable and often isolated.

CONCLUSION

This work strengthens the fact that 7q11.23 CNVs are associated with a broad spectrum of antenatal presentations. IUGR and cardiovascular defects were the most frequent ultrasound signs. By reporting the biggest series of antenatal WBS, we aim to better delineate distinctive signs in fetuses with 7q11.23 CNVs.

A new mouse model of elastin haploinsufficiency highlights the importance of elastin to vascular development and blood pressure regulation

Supravalvular aortic stenosis (SVAS) is an autosomal dominant disease resulting from elastin (ELN) haploinsufficiency. Individuals with SVAS typically develop a thickened arterial media with an increased number of elastic lamellae and smooth muscle cell (SMC) layers and stenosis superior to the aortic valve. A mouse model of SVAS (Eln+/-) was generated that recapitulates many aspects of the human disease, including increased medial SMC layers and elastic lamellae, large artery stiffness, and hypertension. The vascular changes in these mice were thought to be responsible for the hypertension phenotype. However, a renin gene (Ren) duplication in the original 129/Sv genetic background and carried through numerous strain backcrosses raised the possibility of renin-mediated effects on blood pressure. To exclude excess renin activity as a disease modifier, we utilized the Cre-LoxP system to rederive Eln hemizygous mice on a pure C57BL/6 background (Sox2-Cre;Elnf/f). Here we show that Sox2-Cre;Eln+/f mice, with a single Ren1 gene and normal renin levels, phenocopy the original global knockout line. Characteristic traits include an increased number of elastic lamellae and SMC layers, stiff elastic arteries, and systolic hypertension with widened pulse pressure. Importantly, small resistance arteries of Sox2-Cre;Eln+/f mice exhibit a significant change in endothelial cell function and hypercontractility to angiotensin II, findings that point to pathway-specific alterations in resistance arteries that contribute to the hypertensive phenotype. These data confirm that the cardiovascular changes, particularly systolic hypertension, seen in Eln+/- mice are due to Eln hemizygosity rather than Ren duplication.

Clinical phenotypes study of 231 children with Williams syndrome in China: A single-center retrospective study

BACKGROUND

Williams syndrome (WS) is a multisystem neurodevelopmental disorder caused by microdeletions in 7q11.23. This study aims to characterize the clinical phenotypes of Chinese children with WS to help for the early diagnosis and intervention of this disease.

METHODS

231 children diagnosed with WS were retrospectively recruited to the study. Clinical data were analyzed to obtain the incidence of different clinical phenotypes. The occurrence of phenotypes and the influence of gender and age on the incidence of different phenotypes were analyzed.

RESULTS

All WS exhibited facial dysmorphism (100.0%). The majority had neurodevelopmental disorder (91.8%), hoarseness (87.4%) and cardiovascular anomalies (85.7%). The incidence of short stature (46.9%), inguinal hernia (47.2%), hypercalciuria (29.10%), hypercalcemia (9.1%), subclinical hypothyroidism (26.4%) and hypothyroidism (7.4%) were relatively higher. Gender differences were found in supravalvular aortic stenosis (SVAS, p < .001), ventricular septal defect (VSD, p < .05), inguinal hernia (p < .001), superior pulmonary stenosis (SVPS, p < .05) and neurodevelopmental disorder (p < .05). The incidence of neurodevelopmental disorder in WS increased with age (p < .05) while cardiovascular anomalies (p < .001), short stature (p < .001), hypercalciuria (p < .001) and hypercalcemia (p < .01) decreased with age.

CONCLUSIONS

Facial dysmorphism, neurodevelopmental disorder, hoarseness and cardiovascular anomalies were the most common phenotypes. Genetic testing should be suggested to confirm the diagnosis for children with the above abnormalities. Gender and age should be taken into account when making diagnosis and intervention.

Cardiovascular findings in Williams-Beuren Syndrome: Experience of a single center with 127 cases

Williams-Beuren syndrome (WBS) is a rare, microdeletion syndrome characterized by facial dysmorphisms, intellectual disability, a friendly personality, cardiovascular and other abnormalities. Cardiovascular defects (CVD) are among the most prevalent characteristics in WBS, being supravalvular aortic stenosis (SVAS) the most frequent, followed by peripheral pulmonary stenosis (PPS). A comprehensive retrospective review of medical records of 127 patients with molecular diagnosis of WBS, in a period of 20 years, was done to evaluate the incidence, the natural history of cardiovascular disease, and the need for surgical intervention, including heart transplantation (HT). A total of 94/127 patients presented with CVD. Of these 94 patients, 50% presented with SVAS and 22.3% needed heart surgery and/or cardiac catheterization including one that required HT due to severe SVAS-related heart failure at 19 years of age. The patient died in the postoperative period due to infectious complications. Cardiovascular problems are the major cause of sudden death in patients with WBS, who have a significantly higher mortality risk associated with surgical interventions. There is a higher risk for anesthesia-related adverse events and for major adverse cardiac events following surgery. End-stage heart failure due to myocardial ischemia has been described in WBS patients and it is important to consider that HT can become their only viable option. To our knowledge, the case mentioned here is the first HT reported in an adolescent with WBS. HT can be a viable therapeutic option in WBS patients with adequate evaluation, planning, and a multidisciplinary team to provide the required perioperative care and follow-up.

Mid-Aortic Syndrome in Williams-Beuren Syndrome with an Atypical Small-Sized Deletion of Chromosome 7q11.23 Misdiagnosed as Takayasu Arteritis

Mid-aortic syndrome (MAS) is a rare condition characterized by stenosis of the distal thoracic and/or abdominal aorta. Williams-Beuren syndrome (WBS) is a relatively rare cause of MAS. We report a case of incidentally diagnosed MAS caused by WBS without typical manifestations caused by an atypical small-sized deletion in chromosome 7q11.23, which was initially misdiagnosed as Takayasu arteritis.

Intrauterine phenotype features of fetuses with Williams-Beuren syndrome and literature review

Williams-Beuren syndrome (WBS) is a well-defined multisystem chromosomal disorder that is caused by a chromosome 7q11.23 region heterozygous deletion. We explored prenatal diagnosis of WBS by ultrasound as well as multiple genetic methods to characterize the structural variants of WBS prenatally. Expanded noninvasive prenatal testing (NIPT-plus) was elected as a regular prenatal advanced screen for risk assessments of fetal chromosomal aneuploidy and genome-wide microdeletion/microduplication syndromes at the first trimester. At the second and three trimester, seven prenatal cases of WBS were evaluated for the indication of the invasive testing, the ultrasound features, cytogenetic, single-nucleotide polymorphism array (SNP array), and fluorescent quantitative PCR (QF-PCR) results. The NIPT-plus results for seven fetuses were low risk. All cryptic aberrations were detected by the SNP array as karyotyping analyses were negative. Subsequently, QF-PCR further confirmed the seven deletions. Combining our cases with 10 prenatal cases from the literature, the most common sonographic features were intrauterine growth retardation (82.35%, 14/17) and congenital cardiovascular abnormalities (58.82%, 10/17). The manifestations of cardiovascular defects mainly involve supravalvar aortic stenosis (40%, 4/10), ventricular septal defect (30%, 3/10), aortic coarctation (20%, 2/10), and peripheral pulmonary artery stenosis (20%, 2/10). To the best of our knowledge, this is the first largest prenatal study of WBS cases with detailed molecular analysis. Aortic coarctation combined with persistent left superior vena cava and right aortic arch cardiovascular defects were first reported in prenatal WBS cases by our study.

Williams-Beuren syndrome in diverse populations

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.

Clinical application of chromosomal microarray analysis for the diagnosis of Williams-Beuren syndrome in Chinese Han patients

Background

Williams–Beuren syndrome (WBS; OMIM #194,050) is a rare multisystem disorder of a variable phenotypic spectrum caused by a heterozygous microdeletion in the WBS chromosome region (WBSCR) in 7q11.23.

Methods

We screened 38 Chinese Han patients with suspected WBS using chromosomal microarray analysis (CMA).

Results

Pathogenic CNVs were identified in 34 of the patients, including 29 cases with a typical 7q11.23 microdeletion, three cases with atypical copy number variations (CNVs) within the WBS chromosome region and two cases with CNVs associated with other known syndromes. All 29 WBS patients with a typical microdeletion exhibited distinctive facial dysmorphisms and developmental delay. We observed that the incidence of pulmonary abnormalities was slightly higher than that of aortic abnormalities. We also found long philtrum and prominent lips with a thick lip that may warrant suspicion of WBS in the Chinese Han patients.

Conclusion

CMA facilitates diagnosis in individuals with classic/nonclassic features of WBS and demonstrated that when Chinese Han patients present with a less classical phenotype, such as pulmonary abnormalities, this may raise suspicion for a WBS diagnosis and suggest a referral for a genetics evaluation for a differential diagnosis.

Our study demonstrates that although the clinical features of WBS display a highly variable phenotypical spectrum, CMA facilitates diagnosis in individuals with classical and nonclassical features of WBS. In Chinese patients, a less classical phenotype in other races and ethnicities, such as PAS, long philtrum, and global developmental delay, should raise suspicion for WBS and suggest referral for a genetics evaluation and a differential diagnosis.

Modeling age-specific facial development in Williams-Beuren-, Noonan-, and 22q11.2 deletion syndromes in cohorts of Czech patients aged 3-18 years: A cross-sectional three-dimensional geometric morphometry analysis of their facial gestalt

Three-dimensional (3D) virtual facial models facilitate genotype-phenotype correlations and diagnostics in clinical dysmorphology. Within cross-sectional analysis of both genders we evaluated facial features in representative cohorts of Czech patients with Williams-Beuren-(WBS; 12 cases), Noonan-(NS; 14), and 22q11.2 deletion syndromes (22q11.2DS; 20) and compared their age-related developmental trajectories to 21 age, sex and ethnically matched controls in 3-18 years of age. Using geometric morphometry statistically significant differences in facial morphology were found in all cases compared to controls. The dysmorphic features observed in WBS were specific and manifested in majority of cases. During ontogenesis, dysmorphic features associated with increased facial convexity become more pronounced whereas other typical features remained relatively stable. Dysmorphic features observed in NS cases were mostly apparent during childhood and gradually diminished with age. Facial development had a similar progress as in controls, while there has been increased growth of patients' nose and chin in adulthood. Facial characteristics observed in 22q11.2DS, except for hypoplastic alae nasi, did not correspond with the standard description of its facial phenotype because of marked facial heterogeneity of this clinical entity. Because of the sensitivity of 3D facial morphometry we were able to reach statistical significance even in smaller retrospective patient cohorts, which proves its clinical utility within the routine setting.

Cardiovascular disease in Williams syndrome

PURPOSE OF REVIEW

Williams syndrome is a multisystem disorder seen with some regularity at most pediatric centers and usually fairly often at larger centers. Cardiovascular abnormalities, because of elastin deficiency, are the leading cause of morbidity and mortality in patients with Williams syndrome. The present article presents a review of the most recent developments regarding the cardiovascular issues in Williams syndrome.

RECENT FINDINGS

Cardiovascular abnormalities occur in 80% of patients with Williams syndrome, the majority of which are arterial stenoses. The stenoses seen in Williams syndrome now appear to arise from deficient circumferential arterial growth. Pharmacological therapies aimed at improving the vascular stenoses have shown some promise in animal models. Surgical outcomes for supravalvar aortic stenosis are good at most centers. Transcatheter interventions are largely ineffective in Williams syndrome. Multilevel surgical pulmonary artery reconstruction has excellent results for peripheral pulmonary artery stenosis. Periprocedural risk stratification and management algorithms may decrease the risk of cardiovascular complications.

SUMMARY

Cardiovascular abnormalities are a major determining factor in the clinical picture and trajectory of patients with Williams syndrome. Advances in surgical techniques, medical therapeutic options, and periprocedural management hold promise for significant improvements in the cardiovascular outcomes of these patients.

Thinking inside the box: Spatial frames of reference for drawing in Williams syndrome and typical development

BACKGROUND

Successfully completing a drawing relies on the ability to accurately impose and manipulate spatial frames of reference for the object that is being drawn and for the drawing space. Typically developing (TD) children use cues such as the page boundary as a frame of reference to guide the orientation of drawn lines. Individuals with Williams syndrome (WS) typically produce incohesive drawings; this is proposed to reflect a local processing bias.

AIMS

Across two studies, we provide the first investigation of the effect of using a frame of reference when drawing simple lines and shapes in WS and TD groups (matched for non-verbal ability).

METHODS AND PROCEDURES

Individuals with WS (N=17 Experiment 1; N=18 Experiment 2) and TD children matched by non-verbal ability drew single lines (Experiment One) and whole shapes (Experiment Two) within a neutral, incongruent or congruent frame. The angular deviation of the drawn line/shape, relative to the model line/shape, was measured.

OUTCOMES AND RESULTS

Both groups were sensitive to spatial frames of reference when drawing single lines and whole shapes, imposed by a frame around the drawing space.

CONCLUSIONS AND IMPLICATIONS

A local processing bias in WS cannot explain poor drawing performance in WS.

Cytogenomic Aberrations in Congenital Cardiovascular Malformations

Congenital cardiovascular malformations are the most common birth defects, with a complex multifactorial etiology. Genetic factors play an important role, illuminated by numerous cytogenetically visible abnormalities, as well as submicroscopic genomic imbalances affecting critical genomic regions in the affected individuals. Study of rare families with Mendelian forms, as well as emerging next-generation sequencing technologies have uncovered a multitude of genes relevant for human congenital cardiac diseases. It is clear that the complex embryology of human cardiac development, with an orchestrated interplay of transcription factors, chromatin regulators, and signal transduction pathway molecules can be easily perturbed by genomic imbalances affecting dosage-sensitive regions. This review focuses on chromosomal abnormalities contributing to congenital heart diseases and underscores several genomic disorders linked to human cardiac malformations in the last few decades.

Anesthesiological Management of a Patient with Williams Syndrome Undergoing Spine Surgery

Williams Syndrome (WS) is a complex neurodevelopmental disorder associated with a mutation on chromosome 7. Patients with WS usually display dysmorphic facial and musculoskeletal features, congenital heart diseases, metabolic disturbances and cognitive impairment. Structural cardiovascular abnormalities are present in the majority of the children and may provide a substrate for perioperative Sudden Cardiac Death, as presented by several reports, something that creates a great challenge to the anesthetic conduct. We present the case of a 12-year old girl who required anesthetic care for surgical correction of an acquired kyphoscoliosis. Potential anesthesiological implications of WS are subsequently reviewed.

Array CGH - A Powerful Tool in Molecular Diagnostic of Pathogenic Microdeletions - Williams-Beuren Syndrome - A Case Report

ABSTRACT: Williams-Beuren syndrome (WBS) (OMIM 194050) is caused by interstitial deletions or duplications of the 7q11.23 chromosomal region and characterised through a complex phenotype. We described a case diagnosed clinically and genetically confirmed through aCGH. Genetic assessment identified three microdeletions with a total size of 1.35 Mb located at 7q11.23. The deleted regions encompasses more than 30 genes including several protein coding genes such as ELN, LIMK1, FZDS, WBSCR22, WBSCR27, WBSCR28, STX1A, CLDN3, CLDN4, LAT2, ABHD11 or EIF4H .

Williams-Beuren syndrome: pitfalls for diagnosis in limited resources setting

Patients with Williams–Beuren Syndrome can be recognized clinically, given the characteristic dysmorphism, intellectual disability, and behavior. We report on a Congolese boy with typical WBS facial characteristics. He suffered meningitis and coma at the age of 2 years then subsequently presented with profound intellectual disability and atypical behavior. The WBS was only made at age 8.2 years and confirmed with FISH testing and microarray‐CGH. The present report aims to warn clinicians that infections may associate and/or modify a genetic disease as this may be observed in developing countries given the prevalence of infectious diseases.

Joint Attention and Early Social Developmental Cascades in Neurogenetic Disorders

This review examines what is known about joint attention and early social development in three neurogenetic syndromes: Down syndrome, Williams syndrome, and fragile X syndrome. In addition, the potential cascading effects of joint attention on subsequent social development, especially social interaction and social cognition are proposed. The potential issues and complexities associated with conducting prospective, longitudinal studies of infant social development in neurogenetic disorders are discussed.

ROD-CONE DYSTROPHY ASSOCIATED WITH WILLIAMS SYNDROME

PURPOSE

To describe a case of rod-cone dystrophy associated with Williams syndrome.

METHODS

This is an observational case report. The medical history was assessed. Examination included ophthalmoscopy, slit-lamp biomicroscopy, fundus autofluorescence imaging, optical coherence tomography, full-field and multifocal electroretinography, and fluorescence in situ hybridization for genetic testing.

RESULTS

A 14-year-old Asian Indian girl with characteristic facies and heart murmur, and with findings on ophthalmoscopy, slit-lamp biomicroscopy, fundus autofluorescence imaging, optical coherence tomography, full-field electroretinography, and multifocal electroretinography consistent with panretinal rod-cone dystrophy, has been reported. Fluorescence in situ hybridization revealed only 1 copy of the elastin gene on Chromosome 7, confirming the diagnosis of Williams syndrome in this patient.

CONCLUSION

The authors report the first case of a patient with ophthalmic findings characteristic for rod-cone dystrophy in the setting of genetically confirmed Williams-Beuren syndrome.

Chronic antihypertensive treatment improves pulse pressure but not large artery mechanics in a mouse model of congenital vascular stiffness

Increased arterial stiffness is a common characteristic of humans with Williams-Beuren syndrome and mouse models of elastin insufficiency. Arterial stiffness is associated with multiple negative cardiovascular outcomes, including myocardial infarction, stroke, and sudden death. Therefore, identifying therapeutic interventions that improve arterial stiffness in response to changes in elastin levels is of vital importance. The goal of this study was to determine the effect of chronic pharmacologic therapy with different classes of antihypertensive medications on arterial stiffness in elastin insufficiency. Elastin-insufficient mice 4-6 wk of age and wild-type littermates were subcutaneously implanted with osmotic micropumps delivering a continuous dose of one of the following: vehicle, losartan, nicardipine, or propranolol for 8 wk. At the end of treatment period, arterial blood pressure and large artery compliance and remodeling were assessed. Our results show that losartan and nicardipine treatment lowered blood pressure and pulse pressure in elastin-insufficient mice. Elastin and collagen content of abdominal aortas as well as ascending aorta and carotid artery biomechanics were not affected by any of the drug treatments in either genotype. By reducing pulse pressure and shifting the working pressure range of an artery to a more compliant region of the pressure-diameter curve, antihypertensive medications may mitigate the consequences of arterial stiffness, an effect that is drug class independent. These data emphasize the importance of early recognition and long-term management of hypertension in Williams-Beuren syndrome and elastin insufficiency.

Williams syndrome: ophthalmological examination and review of systemic manifestations

PURPOSE

To evaluate the frequency and severity of ophthalmic manifestations and associated diseases, as well as the epidemiological data in patients with Williams syndrome.

METHODS

The authors prospectively studied 30 patients clinically diagnosed as having Williams syndrome as confirmed by the fluorescence in situ hybridization test. Patient history included gender, age, race, education level, previous illnesses, and surgeries. The ophthalmologic examination included best-corrected visual acuity, dynamic and static refraction, extraocular motility test, stereopsis test (Titmus and Lang), and direct and indirect funduscopy.

RESULTS

Thirty patients were included in this study. The mean age was 14.5 ± 1.38 years (range: 7 to 26 years). Fifty percent of the patients were male and 50% were female. Among the children examined, 77% had a refractive error. Hyperopia and astigmatism were noted in 67% and 20% of the patients, respectively, and myopia in 7%. Only one case of amblyopia was noted. On external examination, 23% of children had epicanthus; via biomicroscopy, 3 children with stellate patterns of the irides were observed. Eleven patients (36.6%) had measurable strabismus, 9 (82%) had esotropia, and 2 (18%) had exotropia. Binocular vision was abnormal in 43% of patients. Diffuse arteriovenous tortuosity on funduscopy was observed in 27% of patients.

CONCLUSIONS

Williams syndrome is rare and is associated with multiple phenotypes and diseases that are susceptible to treatment. Multidisciplinary clinical management is critical and, in some cases, surgical intervention is required.

Williams syndrome: a case series

Pediatricians awareness about malformation syndromes can help in their timely diagnosis. Williams syndrome is a microdeletion syndrome associated with characteristic facial features and behavioral phenotype. Diagnosis can be confirmed by fluorescence-in-situ hybridization or multiplex ligation probe amplification. Correct diagnosis can help in diagnosing hypercalcemia and cardiac defects, and providing genetic counseling to the family.

Diagnostically relevant facial gestalt information from ordinary photos

Craniofacial characteristics are highly informative for clinical geneticists when diagnosing genetic diseases. As a first step towards the high-throughput diagnosis of ultra-rare developmental diseases we introduce an automatic approach that implements recent developments in computer vision. This algorithm extracts phenotypic information from ordinary non-clinical photographs and, using machine learning, models human facial dysmorphisms in a multidimensional 'Clinical Face Phenotype Space'. The space locates patients in the context of known syndromes and thereby facilitates the generation of diagnostic hypotheses. Consequently, the approach will aid clinicians by greatly narrowing (by 27.6-fold) the search space of potential diagnoses for patients with suspected developmental disorders. Furthermore, this Clinical Face Phenotype Space allows the clustering of patients by phenotype even when no known syndrome diagnosis exists, thereby aiding disease identification. We demonstrate that this approach provides a novel method for inferring causative genetic variants from clinical sequencing data through functional genetic pathway comparisons.DOI: http://dx.doi.org/10.7554/eLife.02020.001.

Diagnostically relevant facial gestalt information from ordinary photos

Craniofacial characteristics are highly informative for clinical geneticists when diagnosing genetic diseases. As a first step towards the high-throughput diagnosis of ultra-rare developmental diseases we introduce an automatic approach that implements recent developments in computer vision. This algorithm extracts phenotypic information from ordinary non-clinical photographs and, using machine learning, models human facial dysmorphisms in a multidimensional 'Clinical Face Phenotype Space'. The space locates patients in the context of known syndromes and thereby facilitates the generation of diagnostic hypotheses. Consequently, the approach will aid clinicians by greatly narrowing (by 27.6-fold) the search space of potential diagnoses for patients with suspected developmental disorders. Furthermore, this Clinical Face Phenotype Space allows the clustering of patients by phenotype even when no known syndrome diagnosis exists, thereby aiding disease identification. We demonstrate that this approach provides a novel method for inferring causative genetic variants from clinical sequencing data through functional genetic pathway comparisons.DOI: http://dx.doi.org/10.7554/eLife.02020.001.

Clinical and neuropsychiatric status in children with Williams-Beuren Syndrome in Upper Egypt

The aim of this study was to evaluate and explore the clinical, neuropsychiatric status and EEG pattern in a series of children with Williams-Beuren syndrome (WBS) in Assiut, Upper Egypt. We aimed to provide a comprehensive data comparable to what has been published, to enable us to make comparisons across different cultural areas. This will contribute to a better definition of the neuropsychiatric features that may be specific to WBS that allows early and better detection and management of those children.

MATERIALS AND METHODS

A series of 17 WBS children patients who consulted at our hospital were evaluated. The patients were assessed mainly for clinical, neurological, psychiatric and EEG status. We performed FISH for all patients.

RESULTS

All patients had a deletion of the long arm of chromosome 7 (7q 11.23). All had elfin facies. Neurological examination revealed hypotonia in 25% of patients and rigidity (12.50%), brisk deep tendon reflexes (25%), abnormal plantar response (12.50%). Cerebellar and extrapyramidal signs were frequent: dysmetria (31.25%), dysdiadochokinesia (31.25%) and ataxia (18.75%). Epileptic seizures were present in 31.25% of patients and ADHD (37.5%). Autism was present in one patient. EEG abnormalities were present in 31.25%. Congenital cardiopathies were present in 62.50%.

CONCLUSION

Our data showed that WBS children had multi-systemic clinical complications and the management of those patients requires the pediatrician to understand the natural course of this condition, awareness of potential medical problems, and periodic baseline clinical, neuropsychiatric evaluations, monitoring, and rapid intervention to improve the medical care for patients who have WBS.

Looking around houses: attention to a model when drawing complex shapes in Williams syndrome and typical development

Drawings by individuals with Williams syndrome (WS) typically lack cohesion. The popular hypothesis is that this is a result of excessive focus on local-level detail at the expense of global configuration. In this study, we explored a novel hypothesis that inadequate attention might underpin drawing in WS. WS and typically developing (TD) non-verbal ability matched groups copied and traced a house figure comprised of geometric shapes. The house was presented on a computer screen for 5-s periods and participants pressed a key to re-view the model. Frequency of key-presses indexed the looks to the model. The order that elements were replicated was recorded to assess hierarchisation of elements. If a lack of attention to the model explained poor drawing performance, we expected participants with WS to look less frequently to the model than TD children when copying. If a local-processing preference underpins drawing in WS, more local than global elements would be produced. Results supported the first, but not second hypothesis. The WS group looked to the model infrequently, but global, not local, parts were drawn first, scaffolding local-level details. Both groups adopted a similar order of drawing and tracing of parts, suggesting typical, although delayed strategy-use in the WS group. Additionally both groups drew larger elements of the model before smaller elements, suggested a size-bias when drawing.

Facilitating complex shape drawing in Williams syndrome and typical development

Individuals with Williams syndrome (WS) produce drawings that are disorganised, likely due to an inability to replicate numerous spatial relations between parts. This study attempted to circumvent these drawing deficits in WS when copying complex combinations of one, two and three shapes. Drawing decisions were reduced by introducing a number of facilitators, for example, by using distinct colours and including facilitatory cues on the response sheet. Overall, facilitation improved drawing in the WS group to a comparable level of accuracy as typically developing participants (matched for non-verbal ability). Drawing accuracy was greatest in both groups when planning demands (e.g. starting location, line lengths and changes in direction) were reduced by use of coloured figures and providing easily distinguished and clearly grouped facilitatory cues to form each shape. This study provides the first encouraging evidence to suggest that drawing of complex shapes in WS can be facilitated; individuals with WS might be receptive to remediation programmes for drawing and handwriting.

Autism spectrum disorders: the quest for genetic syndromes

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disabilities with various etiologies, but with a heritability estimate of more than 90%. Although the strong correlation between autism and genetic factors has been long established, the exact genetic background of ASD remains unclear. A number of genetic syndromes manifest ASD at higher than expected frequencies compared to the general population. These syndromes account for more than 10% of all ASD cases and include tuberous sclerosis, fragile X, Down, neurofibromatosis, Angelman, Prader-Willi, Williams, Duchenne, etc. Clinicians are increasingly required to recognize genetic disorders in individuals with ASD, in terms of providing proper care and prognosis to the patient, as well as genetic counseling to the family. Vice versa, it is equally essential to identify ASD in patients with genetic syndromes, in order to ensure correct management and appropriate educational placement. During investigation of genetic syndromes, a number of issues emerge: impact of intellectual disability in ASD diagnoses, identification of autistic subphenotypes and differences from idiopathic autism, validity of assessment tools designed for idiopathic autism, possible mechanisms for the association with ASD, etc. Findings from the study of genetic syndromes are incorporated into the ongoing research on autism etiology and pathogenesis; different syndromes converge upon common biological backgrounds (such as disrupted molecular pathways and brain circuitries), which probably account for their comorbidity with autism. This review paper critically examines the prevalence and characteristics of the main genetic syndromes, as well as the possible mechanisms for their association with ASD.

Pediatric ambulatory blood pressure monitoring: indications and interpretations

The prevalence of hypertension in children and adolescents is increasing, especially in obese and ethnic children. The adverse long-term effects of hypertension beginning in youth are known; therefore, it is important to identify young patients who need intervention. Unfortunately, measuring blood pressure (BP) is difficult due to the variety of techniques available and innate biologic variation in BP levels. Ambulatory BP monitoring may overcome some of the challenges clinicians face when attempting to categorize a young patient's BP levels. In this article, the authors review the use of ambulatory BP monitoring in pediatrics, discuss interpretation of ambulatory BP monitoring, and discuss gaps in knowledge in usage of this technique in the management of pediatric hypertension.

Associated disorders of Chiari Type I malformations: a review

A single pathophysiological mechanism of Chiari Type I malformations (CM-I) has been a topic of debate. To help better understand CM-I, the authors review disorders known to be associated with CM-I. The primary methodology found among most of them is deformation of the posterior cranial fossa, usually with subsequent decrease in volume. Other mechanisms exist as well, which can be categorized as either congenital or acquired. In understanding the relationship of such disorders with CM-I, we may gain further insight into the process by which cerebellar tonsillar herniation occurs. Some of these pathologies appear to be true associations, but many appear to be spurious.

Chiari malformation type I: related conditions

Chiari malformation type I (CMI) is a morphological diagnosis defined as the inferior displacement of the cerebellum through the foramen magnum. In parallel to this basic definition of CMI, there are diagnoses that co-exist with CMI in selected patients. In addition, there are specific constellations of clinical symptoms and signs reported in the literature that occur non-randomly in patients affected by CMI. There is no established system that categorizes these CMI-related conditions or even defines them as causes or consequences of CMI. Identifying the relationship between CMI and these associated disorders may allow greater understanding of CMI etiology and potentially inform CMI management.

Drawing the line: drawing and construction strategies for simple and complex figures in Williams syndrome and typical development

In the typical population, a series of drawing strategies have been outlined, which progressively emerge during childhood. Individuals with Williams syndrome (WS), a rare genetic disorder, produce drawings that lack cohesion, yet drawing strategies in this group have hitherto not been investigated. In this study, WS and typically developing (TD) groups drew and constructed (from pre-drawn lines and shapes) a series of intersecting and embedded figures. Participants with WS made use of the same strategies as the TD group for simple intersecting figures, though were less likely to use a typical strategy for more complex figures that contained many spatial relations. When replicating embedded shapes, the WS group used typical drawing strategies less frequently than the TD group, despite attempting to initiate a strategy that is observed in TD children. Results suggested that individuals with WS show a particular difficulty with replicating figures that include multiple spatial relations. The impact of figure complexity and task demands on performance are discussed.

An atypical 7q11.23 deletion in a normal IQ Williams-Beuren syndrome patient

Williams-Beuren syndrome (WBS; OMIM no. 194050) is a multisystemic neurodevelopmental disorder caused by a hemizygous deletion of 1.55 Mb on chromosome 7q11.23 spanning 28 genes. Haploinsufficiency of the ELN gene was shown to be responsible for supravalvular aortic stenosis and generalized arteriopathy, whereas LIMK1, CLIP2, GTF2IRD1 and GTF2I genes were suggested to be linked to the specific cognitive profile and craniofacial features. These insights for genotype-phenotype correlations came from the molecular and clinical analysis of patients with atypical deletions and mice models. Here we report a patient showing mild WBS physical phenotype and normal IQ, who carries a shorter 1 Mb atypical deletion. This rearrangement does not include the GTF2IRD1 and GTF2I genes and only partially the BAZ1B gene. Our results are consistent with the hypothesis that hemizygosity of the GTF2IRD1 and GTF2I genes might be involved in the facial dysmorphisms and in the specific motor and cognitive deficits observed in WBS patients.

Williams syndrome in a preterm infant with phenotype of Alagille syndrome

We report on a preterm infant born at 31 weeks of gestation with a phenotype suggestive of Alagille syndrome, yet microarray analysis identified a deletion on 7q11.23 at the Williams syndrome locus. The infant died on day 18 of life with overwhelming sepsis. This case illustrates the importance of microarray analysis in diagnosing genetic conditions, especially in preterm babies whose facial and other clinical manifestations have not fully developed.