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Background The incidence of orthopedic disorders amongst patients with Prader–Willi Syndrome (PWS) is high when compared to the general pediatric population. The purpose of this retrospective study was to define the most commonly performed orthopedic procedures in pediatric patients with PWS and to characterize the peri-operative outcomes of these patients. Methods The Kids Inpatient Database (KID) was queried to collect data and identify all pediatric patients with PWS who underwent orthopedic procedures from 2001 to 2012. A total of 3684 patients with PWS were identified, 334 of who underwent an orthopedic procedure. Population demographics, comorbidities, and specific procedures undergone were defined. The incidences of postoperative complications and length of associated hospital stay were additionally evaluated. Results Mean age of patients in this sample was 10.33 years (SD 4.5). The most common comorbidities included obesity (18.1%), chronic pulmonary disease (14.1%), hypothyroidism (5.1%), hypertension (5.1%), and uncomplicated diabetes (4%). Common procedures were spinal fusion (165/334, 49%) and lower extremity procedures (50/334, 15%). Complications included acute blood loss anemia, device related complications, pneumonia, sepsis, and urinary tract infections. The overall complication rate was 35.6%. Average hospital lengths of stay for patients undergoing spinal fusion was 6.68 days (SD 4.13), lower extremity orthopedic procedure was 5.65 days (SD 7.4), and all other orthopedic procedures was 7.74 days (SD 16.3). Conclusions Orthopedic disorders are common in patients with PWS. Consequently, spinal fusions and lower extremity procedures are commonly performed in this patient population. Associated comorbid conditions may negatively impact surgical outcomes in these patients. This information should prove useful in the peri-operative management of patients with PWS undergoing orthopedic surgery and for shared decision making with families.

Growth hormone (GH) is an injectable medication originally used to replace the deficiency of the hormone, but has expanded to treating conditions that may reduce growth and adult height even when the body maintains endogenous GH production. In the United States, there are 8 Food and Drug Administration (FDA)-approved indications for pediatric GH therapy: GH deficiency, Prader-Willi Syndrome, small for gestational age (SGA) without catch-up growth, idiopathic short stature, Turner syndrome, SHOX gene haploinsufficiency, Noonan Syndrome, and chronic renal insufficiency. We characterize the growth patterns and effects of GH treatment in each of these indications. We also review patterns of growth that warrant referral to a pediatric endocrinologist, as well as safety updates. This review is intended to guide practitioners on the initial evaluation and management of patients with short stature, and the indications for GH therapy.

Prader-Willi syndrome is a rare genetic neurodevelopmental disorder resulting from the loss of expression of maternally imprinted genes located in the paternal chromosomal region, 15q11-13. Impaired hypothalamic development and function is the cause of most of the phenotypes comprising the developmental trajectory of Prader-Willi syndrome: from anorexia at birth to excessive weight gain preceding hyperphagia, and early severe obesity with hormonal deficiencies, behavioural problems, and dysautonomia. Growth hormone deficiency, hypogonadism, hypothyroidism, premature adrenarche, corticotropin deficiency, precocious puberty, and glucose metabolism disorders are the main endocrine dysfunctions observed. Additionally, as a result of hypothalamic dysfunction, oxytocin and ghrelin systems are impaired in most patients. Standard pituitary and gonadal hormone replacement therapies are required. In this Review, we discuss Prader-Willi syndrome as a model of hypothalamic dysfunction, and provide a comprehensive description of the accumulated knowledge on genetics, pathophysiology, and treatment approaches of this rare disorder.

BACKGROUND: Chromosome 15q11-q13 duplication syndrome (Dup15q) is a neurogenetic disorder caused by duplications of the maternal copy of this region. In addition to hypotonia, motor deficits, and language impairments, Dup15q patients commonly meet the criteria for autism spectrum disorder (ASD) and have a high prevalence of seizures. It is known from mouse models that synaptic impairments are a strong component of Dup15q pathophysiology, however, cellular phenotypes that relate to seizures are less clear. The development of patient-derived induced pluripotent stem cells (iPSCs) provides a unique opportunity to study human neurons with the exact genetic disruptions that cause Dup15q. METHODS: Here, we explored electrophysiological phenotypes in iPSC-derived neurons from four Dup15q patients compared to six unaffected controls, one patient with a 15q11-q13 paternal duplication, and three Angelman syndrome patients. RESULTS: We identified several properties of Dup15q neurons that could contribute to neuronal hyperexcitability and seizure susceptibility. Compared to controls, Dup15q neurons had increased excitatory synaptic event frequency and amplitude and increased density of dendritic protrusions, along with increased action potential firing and decreased inhibitory synaptic transmission. Dup15q neurons also showed impairments in activity-dependent synaptic plasticity and homeostatic synaptic scaling. Finally, Dup15q neurons showed an increased frequency of spontaneous action potential firing compared to control neurons, in part due to disruption of KCNQ2 potassium channels. CONCLUSIONS: Together these data point to multiple electrophysiological mechanisms of hyperexcitability that may provide new targets for the treatment of seizures and other phenotypes associated with Dup15q.

Objective We present prenatal diagnosis of a 15q11.2-q14 deletion of paternal origin associated with increased nuchal translucency (NT), mosaicism for de novo multiple unbalanced translocations involving 15q11-q14, 5qter, 15qter, 17pter and 3qter, and Prader–Willi syndrome (PWS). Case report A 32-year-old, primigravid woman underwent amniocentesis at 18 weeks of gestation because of an increased NT thickness of 5.6 mm and abnormal maternal serum screening results in the first trimester. The pregnancy was conceived by in vitro fertilization and embryo transfer. Amniocentesis revealed a karyotype of 45,XX,der(5)t(5;15)(q35;q14),-15 [16]/45,XX,-15,der(17)t(15;17)(q14;p13)[3]/45,XX,der(15)t(15;15)(q35;q14),-15[2]. The parental karyotypes were normal. Prenatal ultrasound findings were unremarkable. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes revealed the result of arr 15q11.2q14 (22,765,628–38,651,755) × 1.0 [GRCh37 (hg19)] with a 15.886-Mb 15q11.2-q14 deletion encompassing TUBGCP5, CYFIP1, NIPA2, NIPA1, SNRPN, SNURF, SNORD116-1, IPW, UBE3A, ACTC1 and MEIS2. The pregnancy was subsequently terminated, and a malformed fetus with facial dysmorphism was delivered. The cord blood had a karyotype of 45,XX,der(5)t(5;15)(q35;q14),-15[46]/45,XX,der(3)t(3;15) (q29;q14),-15[2]/45,XX,-15,der(17)t(15;17)(q14;p13)[2]. The placenta had a karyotype of 45,XX,der(5) t(5;15)(q35;q14),-15. Polymorphic DNA marker analysis confirmed a paternal origin of the proximal 15q deletion. Conclusion Increased NT and abnormal maternal serum screening results may prenatally be associated with PWS. Chromosome 15 rearrangements in PWS include mosaicism for de novo multiple unbalanced translocations.

Objective The behavioral phenotype of neurogenetic disorders associated with intellectual disability often includes psychiatric comorbidity. The objectives of this systematic review and meta-analysis were to systematically review the prevalence of psychiatric disorders and symptoms in children and adolescents with these disorders and compare phenotypic signatures between syndromes. Method MEDLINE and PsycINFO databases were searched for articles from study inception to December 2018. Eligible articles were peer reviewed, were published in English, and reported prevalence data for psychiatric disorders and symptoms in children and adolescents aged 4 to 21 years using a formal psychiatric assessment or a standardized assessment of mental health symptoms. Pooled prevalence was determined using a random-effects meta-analysis in studies with sufficient data. Prevalence estimates were compared with general population data using a test of binomial proportions. Results Of 2,301 studies identified for review, 39 articles were included in the final pool, which provided data on 4,039 children and adolescents. Ten syndromes were represented, and five were predominant: Down syndrome, 22q11.2 deletion syndrome, fragile X syndrome, Williams syndrome, and Prader-Willi syndrome. The Child Behavior Checklist was the most commonly used assessment tool for psychiatric symptoms. The pooled prevalence with total scores above the clinical threshold was lowest for Down syndrome (32% [95% confidence interval, 19%-44%]) and highest for Prader-Willi syndrome (74% [95% CI, 65%-82%]) with each syndrome associated with significantly higher prevalence than in the general population. Parallel trends were observed for the internalizing and externalizing domains and social subscale scores. Conclusion Differential vulnerability for psychiatric phenotype expression across the disorders was observed. Syndromes with higher levels of social ability or competence appear to offer relative protection against developing psychopathology. This preliminary finding merits further exploration.

A search of the PubMed and Web of Science databases for articles on skin picking in PWS was undertaken identifying case studies; trials of specific treatments; and descriptions of when skin picking occurs, what sites are chosen, and what initiates and sustains this behaviour. Published papers have also considered how skin picking might link to the PWS genotype and whether it is best considered to be part of the repetitive and ritualistic behaviours characteristic of the syndrome. To answer specific questions raised as a result of the review additional analysis was undertaken using data from our earlier population-based study of PWS. We consider this behaviour of skin picking using the framework of the Research Domains Criteria that is cross diagnostic and focuses on the identification of specific neurobiological, psychological and cognitive processes. PWS illustrates the likely interplay between different processes that first initiate and then maintain such behaviour. Treatment development depends on better understanding these mechanisms and their relative contribution to the behaviour.

Objective To investigate the feasibility of progressive resistance training for people with Prader-Willi syndrome (PWS), who have muscle weakness and very low muscle mass. Design Randomised controlled trial with concealed allocation, assessor blinding and intention-to-treat analysis. Setting Community gymnasium. Participants Sixteen participants with PWS (eight female; mean age 25 years) were randomly assigned with 1:1 allocation to an experimental (n = 8) or control group (n = 8). Intervention Progressive resistance training was performed twice a week for 10 weeks. The training was supervised one-to-one by a physiotherapist and comprised seven exercises. The control group continued their usual activities and were offered the training after follow-up assessment. Main outcome measures Three domains of feasibility were evaluated: implementation (attendance and adherence), practicality (safety) and limited efficacy testing. Muscle strength (one repetition maximum for chest and leg press), physical function (box stacking test, timed stairs climb), muscle composition (US) and body composition (whole-body DXA scan) were measured before and after the intervention. Results Participants attended 92% of scheduled sessions and adhered by progressing their training resistance by 82% (range 60–140%). There was one unexpected serious adverse event unrelated to the intervention and several non-serious expected adverse events related to the intervention. Estimates of standardised mean differences indicated moderate to large effects in favour of the experimental group for arm (0.92, 95%CI −0.11 to 1.95) and leg strength (0.78, 95%CI −0.27 to 1.83). The effect was uncertain for secondary outcomes. Conclusions There is preliminary evidence showing progressive resistance training is feasible for people with Prader-Willi syndrome and may increase muscle strength. Clinical Trial Registration Australia New Zealand Clinical Trials Registry ACTRN12616000107426.

Objective Prader-Willi syndrome (PWS) is associated with multiple endocrinopathies, including hypogonadism. The mechanism underlying hypogonadism in PWS is thought to be secondary to hypothalamic dysfunction, primary gonadal defect, or a combination of both. Here, we present a case of hyperestrogenism in PWS due to concomitant polycystic ovary syndrome (PCOS) and therapeutic considerations regarding hormone replacement therapy (HRT). Case Report An 18-year-old woman with PWS transferred to adult care from pediatrics was found to have hyperestrogenism (specifically, elevated estrone with normal estradiol levels). Additionally, she demonstrated oligomenorrhea and hyperandrogenism, meeting diagnostic criteria for PCOS. After 3 months of therapy with cyclic medroxyprogesterone alone, she developed normal withdrawal bleeding. Discussion Given the elevated estrone and normal estradiol levels, our patient’s hyperestrogenism is thought to be a direct result of her hyperandrogenism due to peripheral conversion. Prolonged exposure to unopposed estrogen is an established risk factor for endometrial cancer development in PCOS; thus, this was taken into account regarding her HRT, and she was treated with cyclic progesterone alone. Conclusion Women with PWS are typically treated with combined estrogen and progesterone HRT; however, our case, a unique presentation of PCOS in PWS, demonstrated the importance of tailoring HRT to a patient’s specific needs.

Prader-Willi syndrome (PWS) is a neurobehavioral and epigenetic disorder caused by the deficiency of paternally expressed genes in the chromosome 15q11-q13. This unique molecular defect renders PWS an exciting opportunity to explore epigenetic therapy. Here, we briefly highlight recent findings from small molecule screening and CRISPR/Cas9-mediated epigenome editing that offer promising therapeutic options along with the challenges that remain in developing a successful epigenetic therapy for PWS in humans.

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K+-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS. Keywords: Prader-Willi syndrome, preclinical studies, mouse models of disease, oxytocin, diazoxide, growth hormone, melanocortin, cannabinoid

Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disorder. The molecular mechanism of PWS is deficiency of paternally expressed gene gene or genes from the chromosome 15q11-q13. Due to imprinted gene regulation, the same genes in the maternal chromosome 15q11-q13 are structurally intact but transcriptionally repressed by an epigenetic mechanism. The unique molecular defect underlying PWS renders an exciting opportunity to explore epigenetic-based therapy to reactivate the expression of repressed PWS genes from the maternal chromosome. Inactivation of H3K9m3 methyltransferase SETDB1 and zinc finger protein ZNF274 results in reactivation of SNRPN and SNORD116 cluster from the maternal chromosomes in PWS patient iPSCs and iPSC-derived neurons, respectively. High content screening of small molecule libraries using cells derived from transgenic mice carrying the SNRPN-EGFP fusion protein has discovered that inhibitors of EHMT2/G9a, a histone 3 lysine 9 methyltransferase, are capable of reactivating expression of paternally expressed SNRPN and SNORD116 from the maternal chromosome, both in cultured PWS patient-derived fibroblasts and in a PWS mouse model. Treatment with an EMHT2/G9a inhibitor also rescues perinatal lethality and failure to thrive phenotypes in a PWS mouse model. These findings present the first evidence to support a proof-of-principle for epigenetic-based therapy for the PWS in humans.

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder based on a loss of paternally expressed but maternally imprinted genes in chromosome region 15q11-13. PWS individuals typically show insatiable appetite with subsequent obesity representing the major mortality factor unless food intake is inhibited. The neurobiological basis of PWS-typical hyperphagia has remained poorly understood. Many PWS-typical abnormalities are based on hypothalamic dysregulation, a region in which hunger and satiety are hormonally regulated, with the hormone leptin being a main long-term regulator of satiety. Previous studies in PWS have inconsistently shown leptin alterations solely in early childhood, without investigating the leptin system on an epigenetic level. The present study investigates serum leptin levels (S-leptin) and DNA methylation of the leptin (LEP) and leptin receptor gene (LEPR) promoter in 24 individuals with PWS compared to 13 healthy controls matched for sex, age, and body mass index (BMI) and relates the results to the extent of hyperphagia in PWS. S-Leptin levels were obtained by Enzyme-linked Immunosorbent Assay. LEP/LEPR-promoter DNA methylation was assessed by bisulfite-sequencing, hyperphagia by Hyperphagia Questionnaire for Clinical Trials (HQ-CT). PWS and control groups differed significantly in S-leptin levels with higher S-leptin in PWS. Methylation analysis showed significant differences in mean promoter methylation rate both for LEP and LEPR with a lower methylation rate in PWS. LEPR, but not LEP methylation correlated significantly with S-leptin levels. S-leptin and both LEP and LEPR methylation did not correlate with HQ-CT scores in PWS. The present study is the first to show significantly elevated S-leptin levels in an adult PWS cohort combined with an altered, downregulated LEP and LEPR promoter methylation status compared to sex-, age- and BMI-matched controls. Analogous to previous studies, no link to the behavioral dimension could be drawn. Overall, the results suggest an increased leptin dysregulation in PWS, whereby the findings partly mirror those seen in non-syndromic obesity.

Individuals with Prader-Willi Syndrome (PWS) have reduced mobility, which may be due to altered gait biomechanics. This study compared lower extremity intersegmental coordination and joint kinetics in adults with and without PWS. Walking biomechanics were evaluated in 10 adults with PWS and 10 controls without and 10 with obesity. The foot-shank and shank-thigh coordination was evaluated using modified vector coding and compared between groups using Kruskal-Wallis and Mann-Whitney U tests. The total support moment was summed from the ankle, knee, and hip extensor moments; and relative joint contributions were expressed as a percentage and compared between groups using one-way MANOVA. The group with PWS had greater exclusive shank segment rotation during later stance compared with controls with (p 0.001) and without obesity (p 0.001). The group with PWS also had a smaller absolute total support moment than controls with obesity during early and late stance (both p 0.001), and lower normalized total support moment compared to controls without obesity during early stance (p = 0.019) and compared to controls with obesity during late stance (p = 0.004). Extensor moment contributions was similar between groups during early and late stance (all p 0.05). Findings suggest a flat-footed gait pattern in PWS during late stance, which may negatively influence propulsion and speed. Moreover, those with PWS had lower total support moments than controls during early and late stance, but similar relative extensor contributions when walking at self-selected speeds. As such, improving overall torque generation in the lower extremity may be useful to improve stability and mobility during gait in PWS.

Background Prader-Willi Syndrome (PWS) is a complex multisystem genetic disorder associated with several challenges for people with PWS themselves, and for their families and care givers. Support around access to food is a particular issue due to impaired satiety and, because of this, people with PWS eat excessive amounts of food (hyperphagia). Together with other aspects of the PWS phenotype including, in many cases, a reduced sensitivity to pain, hyperphagia results in life-threatening obesity and life-shortening complications for some people with PWS. Restrictions to liberty and/or access to food raise important legal and ethical considerations in the clinical management of children and adults with PWS. Particularly where disagreements arise and, in the absence of comprehensive guidance for care providers, the courts may be called upon to resolve these difficult issues. Aims 1) To review case-law from English-speaking common law jurisdictions concerning support arrangements for people with PWS with a view to identifying issues that have required the intervention of the courts. 2) To identify principles on which to base clinical guidelines relating to the issues identified, ensuring that such guidelines are consistent with ethical and human rights imperatives. Methods Westlaw, Westlaw AU, and Lexis Nexis were searched for case law concerning the treatment or support of a person with PWS. Results Fifteen cases from jurisdictions in Australia, New Zealand, Canada, the United Kingdom and the United States of America met inclusion criteria. Areas requiring judicial decision making included a) detention in psychiatric hospital; b) support in least restrictive environments c) eligibility for support services; d) guardianship; e) access to special education. Judicial decisions are discussed in the context of the United Nations' Convention on the Rights of Persons with Disabilities.

This paper proposes that tVNS has the potential to be a new treatment for some of the behaviour difficulties that may affect people with intellectual disabilities and/or autism, particularly those people born with specific neurodevelopmental syndromes. Behaviours, such as emotional outbursts, physical aggression, and self-injury are a relative common occurrence in these groups and have a significant impact on wellbeing and quality of life for the individuals and their families. Such behaviours have generally been understood through the lens of learning theory, the likelihood of their occurrence being shaped and reinforced by the responses of others. However, when vagus nerve stimulation has been used to treat epilepsy improvements in cognition, behaviour, and general wellbeing have been noted suggesting that with these behaviours other causal mechanisms are also important. More recently incidental findings from a proof of concept study where vagus nerve stimulation was given, using an implanted device, to people with the genetically determined neurodevelopmental disorder, Prader-Willi Syndrome (PWS), findings of benefit supported the above view. A second study, this time using tVNS, reported a similar result. In this paper we review the evidence for the use of tVNS for behavioural problems, consider the challenges when conducting trials in this population, and reflect on what the preliminary observations in people with PWS tell us about the possible mechanisms that underpin such behaviours.

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by deficiency of paternal gene expression in the 15q11.2-q13 chromosome imprinted region. Hyperphagia and dysgnosia are typical clinical features in the early-childhood of patient. We generated an induced pluripotent stem cell (iPSC) line SMBCi011-A from a 6 years old male PWS patient, the line expressed pluripotent signs and had ability to differentiate into three germ layers in vivo.

Prader-Willi Syndrome (PWS) is a multi-system genetically determined neurodevelopmental disorder and the commonest cause of syndromal obesity. The development of hyperphagia in early childhood is part of the phenotype arising as a result of an impaired neural response to food intake and the inability to regulate food intake in line with energy needs. Severe obesity develops if access to food is not controlled. In this review we evaluate the evidence for increased morbidity and mortality in PWS in order to establish the extent to which it is directly related to the obesity; a consequence of the eating behaviour itself independent of obesity; or associated with other characteristics of the syndrome. Medline, Cochrane, PsychINFO, CINAHL, Web of Science and Scopus databases were used to systematically identify published material on PWS and hyperphagia and syndrome-related morbidity and mortality. One hundred and ten key papers were selected. Data on 500 people with PWS indicated that the average age of death was 21 years and obesity was, as expected, a significant factor. However, the behaviour of hyperphagia itself, independent of obesity, was also important, associated with choking, gastric rupture, and/or respiratory illness. Other syndrome-related factors increased the risk for, and seriousness of, co-morbid illness or accidents. We conclude that improving life-expectancy largely depends on managing the immediate non-obesity and obesity-related consequences of the hyperphagia, through improved support. The development of new treatments that significantly reduce the drive to eat are likely to decrease morbidity and mortality improving quality of life and life expectancy.

Excess fat mass is a cardinal feature of Prader-Willi syndrome (PWS) that is recapitulated in the Magel2-null mouse model of this genetic disorder. There is a pressing need for drugs that can prevent or treat obesity in children with PWS. Recently, a clinical study of a controlled release form of the benzothiadiazine derivative diazoxide demonstrated improved metabolic parameters and decreased fat mass in obese children and adults with PWS. We tested whether chronic diazoxide administration can reduce fat mass and improve metabolism in mice lacking MAGEL2, a gene inactivated in PWS. Magel2-null and wild-type control mice were rendered obese by high fat diet feeding, then provided diazoxide while being maintained on a high fat diet. Treatment of obese mice with diazoxide reduced weight and body fat, lowered blood glucose and improved endurance capacity. Treatment with diazoxide partially normalizes obesity in children and adults with PWS and in a PWS mouse model, demonstrating that the biological pathways impacted by diazoxide may be rational pharmacological targets in PWS and other disorders diseases associated with obesity.

Human GH is present in pituitary and circulation as several isoforms, the prevalent being 22 kDa- and 20 kDa-GH. Recently, we have demonstrated the preservation of a normal balance in GH isoforms after GH releasing hormone (GHRH) plus arginine (ARG) administration in adult patients with Prader-Willi syndrome (PWS), one of the most common causes of syndromic obesity, often associated with GH deficiency (GHD). Aim of the present study was to measure circulating levels of 22 kDa- and 20 kDa-GH in young PWS patients (n = 24; F/M: 10/14; genotype UPD/DEL/met +: 11/11/2; age: 10.8 ± 5.3 years; BMI SDS: 2.0 ± 2.0; GHD: 16/24; obesity: 12/24) after combined GHRH + ARG or ARG administration. The results were analysed subdividing the GHRH + ARG and ARG groups on the basis of PWS genotype, GHD status and obesity. Circulating levels of 22 kDa- and 20 kDa-GH were measured by a chemiluminescent or fluorescent method based on specific pairs of monoclonal antibodies. GHRH + ARG or ARG significantly stimulated the secretion of 22 kDa-GH but not that of 20 kDa-GH in all PWS patients. No significant GHRH + ARG- vs. ARG-induced changes in the ratios of 22 kDa- to 20 kDa-GH peaks were observed in all PWS patients, although 22 kDa- or 20 kDa-GH peaks were significantly higher in the GHRH + ARG than ARG group. When subdividing PWS patients in UPD vs. DEL, obese vs. non obese and GHD vs. non GHD subgroups, GH peaks were significantly higher in nonobese than obese patients and in non GHD than GHD patients administered with either GHRH + ARG or ARG test, apart from the comparisons in the DEL/UPD subgroups. Anyway, the ratios of peak levels of 22 kDa- to 20 kDa-GH were similar after GHRH + ARG vs. ARG in all subgroups investigated. In conclusion, this study shows that administration of two different pharmacological tests, i.e. ARG, capable of reducing hypothalamic somatostatinergic tone, and GHRH (+ ARG), that directly acts at pituitary level on the somatotropic cell, evokes the same ratios of GH isoforms in young PWS patients, suggesting that the hypothalamic dysfunction in this genetic disorder does not alter the qualitative and quantitative composition of GH isoforms present in circulation.

Objective A growth hormone receptor (GHR) gene polymorphism impacts sensitivity to endogenous and exogenous growth hormone (GH) to moderate growth and development. Increased sensitivity may accelerate spinal growth and contribute to scoliosis, particularly in GH-deficient and treated populations such as Prader-Willi syndrome (PWS). Therefore, we examined the relationship between GHR genotype and scoliosis (case and control) in PWS cohorts. Design We utilized a case-control design in a study of 73 subjects (34M; 39F) with genetically confirmed PWS in 32 individuals previously diagnosed with moderate to severe scoliosis (mean age = 16.9 ± 10.2 years; age range of 1 to 41 years) and 41 adults with no evidence of scoliosis (mean age = 30.8 ± 9.7 years; age range of 18 to 56 years). The GHR gene polymorphism was determined using PCR specific primers to capture the two recognized GHR gene fragment sizes [i.e., full length (fl) or exon 3 deletions (d3)]. Results Twenty-three (72%) of the 32 case subjects with scoliosis required surgical correction with an approximately equal balance for gender and PWS genetic subtype among cases and 41 control subjects without scoliosis. The GHR d3/d3 genotype was identified in N = 2 of 8 (25%) cases with scoliosis and the d3/fl genotype was identified in N = 11 of 25 (44%) cases with scoliosis but the distribution difference did not statistically differ. The GHR fl/fl genotype was correlated with a significantly faster rate and heavier weight gain among case subjects. Conclusion Our examination of demographic and genetic markers associated with scoliosis and surgical repair in PWS found no evidence to support differences in gender, PWS genetic subtype or GHR d3 allele distributions among the case vs control groups. Those with fl/fl alleles were heavier than those with d3/d3 or d3/fl genotypes and warrant further study with a larger sample size and possibly to include other vulnerable populations requiring growth hormone treatment.

Introduction The Prader-Willi syndrome (PWS) is a rare genetic disorder caused by absence of expression of the paternal alleles in region 15q11.2-q13. Obesity and hormonal deficiencies, especially of growth hormone (GH), are the most important signs from the therapeutic viewpoint. Recombinant GH (rGH) is effective in children and represents the mainstay in treatment; by contrast, little evidence in available in adult patients. Objective To review the reported evidence on the beneficial and adverse effects of treatment with rGH in children and adults. Design A review was made of 62 original articles published between 2000 and 2017 using the PubMed database. Results In pediatric and adult PWS, rGH improves body morphology and composition, physical performance, cognition, psychomotor development, respiratory function, and quality of life with few adverse effects. Conclusions Treatment with rGH is effective and safe and improves quality of life in both children and adults with PWS.

PurposePrader-Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia and morbid obesity with increased cardiopulmonary and hyperphagia-related mortality. Survival trends in PWS were evaluated to assess the impact of modern interventions on mortality risk.MethodsThe Prader-Willi Syndrome Association (USA) 40-year mortality syndrome-specific database of 486 death reports was utilized to examine survival trends in PWS and cohort effects for recent deaths (years 2000-2015, N=331) relative to deaths prior to 2000 (N=94). Cox proportional hazards regression modeling was applied to generate log rank statistics and Kaplan-Meier curves examining sex, cause of death, and cohort.ResultsRisk for all-cause mortality in PWS was 1.5 (95% confidence interval (CI)=1.2-1.9) times higher for the Early than the Recent era cohort reflected in female cardiac failure (hazard ratio (HR)=1.8; 95% CI=1.3-2.6), pulmonary embolism (HR=6.1; 95% CI=1.7-22), and gastrointestinal-related (HR=3.2; 95% CI=1.1-7.4) causes. Accidental deaths in males increased in the Recent era cohort (HR=5.7; 95% CI=1.2-27.1), possibly due to enhanced weight management and mobility. Risk of death from respiratory failure was unchanged.ConclusionWe report measurable increases in survival effecting cardiovascular and gastrointestinal-related causes in PWS most likely attributable to earlier diagnosis and proactive interventions to prevent morbid obesity. More research is needed to address underlying vulnerability to respiratory failure, an unchanged mortality risk in PWS.

Prader-Willi syndrome (PWS) is a complex genetic disorder and represents the most common genetic cause of life-threatening obesity in childhood and adolescence. The indication for bariatric surgery in children and adolescents with syndromic obesity is still controversial. This case report deals with the preoperative medical and psychosocial evaluation of a 16-y-old male adolescent with PWS who underwent sleeve gastrectomy. Information on a 6-mo follow-up is also reported. The preoperative body weight was 223 kg (body mass index [BMI] 80.9 kg/m2). Comorbidities included severe obstructive sleep apnea with nocturnal respiratory failure, hypertension, and impaired glucose tolerance. At 2- and 6-mo follow-ups, the percent excess weight loss was 16 (BMI 71.8 kg/m2) and 29.2 (BMI 64.6 kg/m2), respectively. Comorbities did improve. Intellectual disability of genetic origin per se may not represent an absolute contraindication to bariatric surgery if adequate and tailored clinical and psychosocial support is provided.

Prader-Willi syndrome is a complex endocrinological and developmental disorder characterized by hyperphagic, autistic, and obsessive behaviors, which have been considered to primarily originate from hypothalamus-pituitary axis system alterations in the brain. While the pituitary gland has been demonstrated to contribute to behavioral phenotypes associated with neuropeptide, e.g., arginine-vasopressin, the relevant alterations in Prader-Willi syndrome remain unknown. This study aimed to investigate developmental abnormalities in the pituitary gland structures and determine whether the structural abnormalities are associated with behavioral characteristics in Prader-Willi syndrome. In total, 21 Japanese individuals with Prader-Willi syndrome and 31 healthy controls with typical development were included. Compared with the control group, the Prader-Willi syndrome group showed reduced anterior and posterior pituitary volume ratios per total intracranial volume with relative T1 shortening in an age-associated manner. Moreover, altered volume ratios and signal intensities were negatively correlated with hyperphagia and autistic questionnaire scores but positively correlated with obsessive scores. The findings suggest that structural and functional alterations, in part due to altered hypothalamus-pituitary function, may contribute to the behavior in Prader-Willi syndrome. The imaging-behavior correlates and in vivo neurochemical visualization of the pituitary gland might be potential intrinsic biomarkers for behavioral phenotypes in Prader-Willi syndrome and other neurodevelopmental disorders.

Introduction Sleep-disordered breathing (SDB) is common in children with PWS. In the current study, we aimed to evaluate the severity of SDB in patients with PWS using polysomnography (PSG), and assess the effect of the underlying genetic mechanism on PSG parameters. Methods Children with PWS, referred to our sleep laboratory between March 2016 and January 2020 were enrolled. PSG parameters, demographic data, body mass index (BMI), and symptoms related to SDB were recorded. The effect of non-invasive ventilation strategies and the outcome of therapy on PSG parameters were evaluated. Results In our study, 64.5% of the patients had severe sleep apnea syndrome (total apnea hypopnea index (AHI) ≥10 events/hour). 22.6% had significantly high (>5 events/hour) central sleep apnea. Patients with a deletion had significantly lower initial and mean SaO2, longer sleep time SaO2 under 90%, oxygen desaturation % and total AHI when compared to those with uniparental disomy. PSG parameters were similar between patients who did or didn't receive growth hormone treatment. Conclusion The majority of the PWS patients had severe sleep apnea syndrome characterized mainly by hypopneas which were accompanied by central apneas. There was a more severe impact on oxygen parameters and total AHI in patients with deletions.

Background Prader-Willi syndrome (PWS) is a complex developmental genetic disorder associated with intellectual disability and deficits in executive functions which result in disorganisation and poor personal autonomy. Aims This study aimed to determine impairments in planning skills of adults with PWS, in relation with their intellectual disabilities, as well as the influence of food compulsions on their performance. Methods and procedures A modified version of the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome was used in three groups: a group of adults with PWS in comparison with two groups both matched on chronological age, one with typical development (TD) and one with intellectual disability (ID). Outcomes and results Compared to TD adults, both adults with PWS and ID showed increased planning time and lower raw scores on the planning task. The execution time and the number of errors were higher in the PWS group compared to the comparison groups. All three groups performed worse in the non-food condition only for number of errors and raw score. Conclusions and implications Planning abilities were impaired in PWS adults. Results also showed that intellectual level plays a role in participants’ performance. These findings are essential to understand the difficulties of people with PWS daily life.

Human brain organoids represent remarkable platforms for recapitulating features of human brain development and diseases. Existing organoid models do not resolve fine brain subregions, such as different nuclei in the hypothalamus. We report the generation of arcuate organoids (ARCOs) from human induced pluripotent stem cells (iPSCs) to model the development of the human hypothalamic arcuate nucleus. Single-cell RNA sequencing of ARCOs revealed significant molecular heterogeneity underlying different arcuate cell types, and machine learning-aided analysis based on the neonatal human hypothalamus single-nucleus transcriptome further showed a human arcuate nucleus molecular signature. We also explored ARCOs generated from Prader-Willi syndrome (PWS) patient iPSCs. These organoids exhibit aberrant differentiation and transcriptomic dysregulation similar to postnatal hypothalamus of PWS patients, indicative of cellular differentiation deficits and exacerbated inflammatory responses. Thus, patient iPSC-derived ARCOs represent a promising experimental model for investigating nucleus-specific features and disease-relevant mechanisms during early human arcuate development.

Prader-Willi syndrome (PWS) is a rare disease associated with cognitive impairment, hypotonia, hyperphagia (an insatiable hunger), and obesity. Therapies that target hyperphagia are in development, but understanding the value of these therapies to inform patient-focused drug development (PFDD) requires valid data on disease burden. We estimated disease burden by measuring and comparing quality-adjusted life-years (QALYs) for 3 PWS health states relevant to current PFDD initiatives.Time trade-off (TTO) and a visual analog scale (VAS) were used to elicit PWS caregivers' values for 3 fixed health states for a standardized patient described with (1) untreated PWS, (2) PWS with controlled obesity, and (3) PWS with controlled obesity and hyperphagia. We excluded participants who left at least 1 TTO or VAS question blank or incomplete (noncompleters) and respondents who reported the same answer for all TTO scenarios (nontraders). The remaining group of respondents (traders) were used for all primary analyses. We assessed validity and bias of QALY estimates by comparing differences in health state valuations, treatment priorities, and characteristics among respondents who did and did not complete the TTO.A total of 458 respondents completed the survey, including 226 traders, 93 nontraders, and 139 noncompleters. Traders valued untreated PWS at 0.69 QALYs, PWS with controlled obesity at 0.79 QALYs, and controlled hyperphagia/obesity at 0.91 QALY (P0.01 for differences among health state values). Reported VAS ratings were similar for traders versus nontraders for untreated PWS (38.64 vs 38.95, P = 0.89) and PWS with controlled obesity (57.36 vs 55.14, P = 0.35) but varied for PWS with controlled obesity and hyperphagia (70.70 vs 64.46, P = 0.02). Exclusion of noncompleters did not introduce obvious bias because traders and noncompleters were similar in treatment priorities and characteristics. The exclusion of nontraders did not meaningfully alter mean or distribution of valuations.This study found that avoiding hyperphagia decreases the burden of PWS and that these results are robust, even once imposing strict inclusion criteria. Use of fixed health states to estimate QALYs addresses many of the complexities of measuring disease burden in rare and pediatric conditions, indicating the potential value of this approach to inform premarket decision makers in identifying outcome importance.

Here we report the smallest deletion involving SNURF/SNRPN that causes major symptoms of Prader-Willi syndrome (PWS), including hypotonia, dysmorphic features, intellectual disability, and obesity. A female patient with the aforementioned and additional features was referred to the Mayo Clinic Cytogenetics laboratory for genetic testing. Chromosomal microarray analysis and subsequent Sanger sequencing identified a de novo 6.4 kb deletion at 15q11.2, containing exon 1 of the SNURF gene and exon 1 of the shortest isoform of the SNRPN gene. SNURF/SNRPN exon 1, which is methylated on the silent maternal allele, is associated with acetylated histones on the expressed paternal allele. This region also overlaps with the PWS-imprinting center (IC). Subsequent molecular methylation analysis was performed using methylation-specific MLPA (MS-MLPA), which characterized that the deletion of SNURF/SNRPN exon 1 was paternal in origin, consistent with the PWS-like phenotype. Since SNURF/SNRPN gene and the PWS-IC are known to regulate snoRNAs, it is likely that the PWS-like phenotype observed in patients with paternal SNURF/SNRPN deletion is due to the disrupted expression of SNORD116 snoRNAs.

Objective Evaluate benefit and risk of low dose growth hormone treatment (GHT, 4.5 mg/m2/week) in very young children with Prader-Willi Syndrome (PWS). Design Prospective longitudinal clinical intervention. Methods We evaluated 31 infants (aged 2–12 months) and 42 toddlers (13–24 months) from the PWS-OZGROW database for height, weight and BMI using the World Health Organization standard deviation scores (SDSWHO) and PWS specific BMI (SDSPWS), bone age, insulin-like growth factor 1 (IGF-I) levels and adverse events over 3 years of GHT. Results At commencement of GHT infants had a lower BMI SDSWHO (− 0.88 vs 0.40) than toddlers, while toddlers had a lower height SDSWHO (− 1.44 vs − 2.09) (both P

Melanoma antigen (MAGE) genes are conserved in all eukaryotes and encode for proteins sharing a common MAGE homology domain. Although only a single MAGE gene exists in lower eukaryotes, the MAGE family rapidly expanded in eutherians and consists of more than 50 highly conserved genes in humans. A subset of MAGEs initially garnered interest as cancer biomarkers and immunotherapeutic targets due to their antigenic properties and unique expression pattern that is primary restricted to germ cells and aberrantly re-activated in various cancers. However, further investigation revealed that MAGEs not only drive tumorigenesis, but also regulate pathways essential for diverse cellular and developmental processes. Therefore, MAGEs are implicated in a broad range of diseases including neurodevelopmental, renal, and lung disorders, as well as cancer. Recent biochemical and biophysical studies indicate that MAGEs assemble with E3 RING ubiquitin ligases to form MAGE-RING ligases (MRLs) and act as regulators of ubiquitination by modulating ligase activity, substrate specification, and subcellular localization. Here, we present a comprehensive guide to MAGEs highlighting the molecular mechanisms of MRLs, their physiological roles in germ cell and neural development, oncogenic functions in cancer, and potential as therapeutic targets in disease.

Prader-Willi syndrome (PWS) is the most common genetic obesity syndrome, with associated learning difficulties, neuroendocrine deficits, and behavioural and psychiatric problems. As the life expectancy of individuals with PWS increases, there is concern that alterations in brain structure associated with the syndrome, as a direct result of absent expression of PWS genes, and its metabolic complications and hormonal deficits, might cause early onset of physiological and brain aging. In this study, a machine learning approach was used to predict brain age based on grey matter (GM) and white matter (WM) maps derived from structural neuroimaging data using T1-weighted magnetic resonance imaging (MRI) scans. Brain-predicted age difference (brain-PAD) scores, calculated as the difference between chronological age and brain-predicted age, are designed to reflect deviations from healthy brain aging, with higher brain-PAD scores indicating premature aging. Two separate adult cohorts underwent brain-predicted age calculation. The main cohort consisted of adults with PWS (n = 20; age mean 23.1 years, range 19.8–27.7; 70.0% male; body mass index (BMI) mean 30.1 kg/m2, 21.5–47.7; n = 19 paternal chromosome 15q11–13 deletion) and age- and sex-matched controls (n = 40; age 22.9 years, 19.6–29.0; 65.0% male; BMI 24.1 kg/m2, 19.2–34.2) adults (BMI PWS vs. control P = .002). Brain-PAD was significantly greater in PWS than controls (effect size mean ± SEM +7.24 ± 2.20 years [95% CI 2.83, 11.63], P = .002). Brain-PAD remained significantly greater in PWS than controls when restricting analysis to a sub-cohort matched for BMI consisting of n = 15 with PWS with BMI range 21.5–33.7 kg/m2, and n = 29 controls with BMI 21.7–34.2 kg/m2 (effect size +5.51 ± 2.56 years [95% CI 3.44, 10.38], P = .037). In the PWS group, brain-PAD scores were not associated with intelligence quotient (IQ), use of hormonal and psychotropic medications, nor severity of repetitive or disruptive behaviours. A 24.5 year old man (BMI 36.9 kg/m2) with PWS from a SNORD116 microdeletion also had increased brain PAD of 12.87 years, compared to 0.84 ± 6.52 years in a second control adult cohort (n = 95; age mean 34.0 years, range 19.9–55.5; 38.9% male; BMI 28.7 kg/m2, 19.1–43.1). This increase in brain-PAD in adults with PWS indicates abnormal brain structure that may reflect premature brain aging or abnormal brain development. The similar finding in a rare patient with a SNORD116 microdeletion implicates a potential causative role for this PWS region gene cluster in the structural brain abnormalities associated primarily with the syndrome and/or its complications. Further longitudinal neuroimaging studies are needed to clarify the natural history of this increase in brain age in PWS, its relationship with obesity, and whether similar findings are seen in those with PWS from maternal uniparental disomy., Highlights • Prader-Willi syndrome is the commonest genetic obesity syndrome. • 19 of the 20 adults with PWS had a paternal deletion in chromosome 15q11–13. • Adults with PWS had increased brain age using structural MRI with machine learning. • This was independent of their higher BMI, and use of growth and sex hormones. • Another man with a SNORD116 microdeletion also had an increased brain age.

The aim of this study was to explore the feasibility of measuring a postprandial increase in energy expenditure (ΔEE) using a state-of-the-art whole-body calorimetry unit (WBCU) in children and youth with Prader-Willi syndrome (PWS). Five participants (aged 10–25 y) received both a standard and a high-protein diet in a random order (crossover design). Resting energy expenditure, postprandial ΔEE 6 h after intake of a standard [15% of total energy (TE)] and a high-protein (30% TE) meal, and respiratory exchange ratio (RER) were measured in a WBCU. No differences were observed in ΔEE comparing the 2 meals. Mean RER was lower following the high-protein meal (0.80 ± 0.01) compared with the standard meal (0.87 ± 0.02) (P = 0.009). Despite the high participant burden, it was feasible to conduct this metabolic test in children and youth with PWS. This study paves the way for further studies targeting EE in this patient population.

Background Behavioural support for young people with Prader-Willi syndrome (PWS) is necessary in home and school environments. The Trauma Informed Practice (TIP) framework has been used to support young people with complex behavioural needs in school settings. Aims To identify parent and professional perspectives on behavioural challenges experienced by young people with PWS and strategies for supports, to inform understanding of how they are aligned with the TIP framework. Method Semi-structured interviews were conducted with eight families with a 12–21 year old child with PWS, four clinicians and two teachers to investigate the contexts and mechanisms associated with challenging, calm and productive behaviours. Data were analysed using directed content analysis, using TIP principles as a framework. Results Strategies to support young people with PWS aligned with the four overarching TIP Principles:Empowerment, voice and choice; Creating safe environments; Creating a collaborative environment; and Trustworthiness and transparency. Additional Novel domains included: Behavioural underpinnings, Modifying environments and Supporting family capacity. Conclusion These novel domains can be used to supplement the TIP framework for guidance on how to support young people with PWS. Health implications Development and implementation of strategies to reduce behavioural difficulties in young people with PWS through positive support mechanisms could improve function and social engagement within their families and communities.

Prader-Willi Syndrome (PWS) is characterized by decreased social and emotional functioning. Due to the low base-rate of children with PWS, developing behavioral interventions for individuals with PWS is faced with the challenge of enrolling enough local participants for adequate study of behavioral intervention efficacy. However, these types of studies are greatly needed in PWS and telehealth methodology may be useful in addressing this challenge. This article is a follow-up to a previous feasibility study (Dimitropoulos et al., 2017) and reports on the preliminary efficacy of a telehealth intervention delivered to 15 children, ages 6-12, with PWS. Overall, children demonstrated significantly improved cognitive and affective processes in pretend play and general cognitive flexibility following the 6-week remote intervention. These findings are limited by the lack of control group and small sample size which should be considered when interpreting results. Overall, these preliminary findings point to the potential role pretend play can serve as a means of enacting cognitive and behavioral change via telehealth.

Background Prader-Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia, obesity, cardiopulmonary diseases, and increased mortality. Although successful weight loss improves health in PWS, few treatments cause sustained weight loss in obese patients let alone obese individuals with PWS. Objectives The present study uses the Magel2 knockout (KO) mouse, an animal model of PWS, to conduct a preclinical study on the efficacy of sleeve gastrectomy (SG) in PWS. Setting Academic research laboratory, United States. Methods We performed sham or SG surgeries in 24- to 28-week-old male Magel2 KO and wild-type littermate control mice (WT) who had been maintained on a high-fat diet for 10 weeks. We monitored weight, food intake, and fat and lean mass pre- and postoperatively. Fasting glucose, glucose tolerance, and counter-regulation were measured postoperatively. Results Magel2 KO animals had similar recovery and mortality rates compared with WT. SG resulted in similar weight loss, specifically loss of fat but not lean mass, in both Magel2 KO and WT mice. SG also resulted in significantly lower fasting glucose levels and a reduction in fat intake in both Magel2 KO and WT mice. We also found that Magel2 KO mice failed to increase their food intake in response to the glucoprivic agent 2-deoxy-D-glucose, suggesting impaired glucose counter-regulation, but this occurred regardless of surgical status. All results were considered significant when P Conclusion We find in this mouse model of PWS, SG is a well-tolerated, effective strategy for weight and fat loss.

Reduced ocular pigmentation is common in Angelman syndrome (AS) and Prader-Willi syndrome (PWS) and is long thought to be caused by OCA2 deletion. GABRB3 is located in the 15q11-13 region flanked by UBE3A, GABRA5, GABRG3, and OCA2. Mutations in GABRB3 have frequently been associated with epilepsy and autism, consistent with its role in neurodevelopment. We report here a robust phenotype in the mouse in which deletion of Gabrb3 alone causes nearly complete loss of retinal pigmentation due to atrophied melanosomes, as evidenced by electron microscopy. Using exome and RNA sequencing, we confirmed that only the Gabrb3 gene was disrupted while the Oca2 gene was intact. However, mRNA abundance of Oca2 and other genes adjacent to Gabrb3 is substantially reduced in Gabrb3−/− mice, suggesting complex transcriptional regulation in this region. These results suggest that impairment in GABRB3 downregulates OCA2 and indirectly causes ocular hypopigmentation and visual defects in AS and PWS.

Prader-Willi syndrome (PWS) results from under-expression of the paternally-derived chromosomal region 15q11-13. Growth failure is a recognized feature of PWS, and both quantitative and qualitative defects of the GH/IGF-I axis revealing GH deficiency (GHD) have been demonstrated in most children with PWS. In PWS adults, criteria for GHD are biochemically fulfilled in 8-38% of the studied cohorts. Published data support benefits of early institution of GH therapy (GHT) in PWS children, with positive effects on statural growth, body composition, metabolic homeostasis, and neurocognitive function. Like in pediatric PWS, GHT also yields beneficial effects on lean and body fat, exercise capacity, and quality of life of PWS adults. Although GHT has been generally administered safely in PWS children and adults, careful surveillance of risks is mandatory during prolonged GH replacement for all PWS individuals.

Prader-Willi syndrome (PWS) is a syndromic obesity caused by loss of paternal gene expression in an imprinted interval on 15q11.2-q13. Induced pluripotent stem cells were generated from skin cells of three large deletion PWS patients and one unique microdeletion PWS patient. We found that genes within the PWS region, including SNRPN and NDN, showed persistence of DNA methylation after iPSC reprogramming and differentiation to neurons. Genes within the PWS minimum critical deletion region remain silenced in both PWS large deletion and microdeletion iPSC following reprogramming. PWS iPSC and their relevant differentiated cell types could provide in vitro models of PWS.

We report a 20 year follow up on a Caucasian female, now 26 years of age, with Prader-Willi syndrome (PWS) harboring an atypical 15q11-q13 submicroscopic deletion of 100–200 kb in size first detected in 1996 involving the imprinting center, SNRPN gene and surrounding region. PWS is a rare complex disorder caused by the loss of paternally expressed genes in the 15q11-q13 region. With high resolution chromosomal microarray and methylation – specific MLPA analysis, we updated the genetic findings on our patient and found a 209,819bp deletion including the SNURF-SNRPN gene complex which includes the imprinting center and the SNORD116 region. We compared with four other similarly reported individuals in the literature with atypical submicroscopic deletions within this region but without imprinting center involvement to better characterize the specific genetic lesions causing PWS clinical findings. Clinically, our patient met the diagnostic criteria of PWS including infantile hypotonia, a poor suck with feeding difficulties, global developmental delays and later food foraging, childhood obesity, small hands and skin picking. Small atypical deletions of comparable sizes were seen in the 15q11-q13 region in all five cases and similar behavioral/physical characteristics were found despite an imprinting defect in our patient. These results further support an overlapping critical deletion region involving the non-coding snoRNA SNORD116 in common in the five individuals playing a key role in contributing to the PWS phenotype.

Contains fulltext : 167696.pdf (Publisher’s version ) (Open Access) Genomic imprinting is a mechanism in which gene expression varies depending on parental origin. Imprinting occurs through differential epigenetic marks on the two parental alleles, with most imprinted loci marked by the presence of differentially methylated regions (DMRs). To identify sites of parental epigenetic bias, here we have profiled DNA methylation patterns in a cohort of 57 individuals with uniparental disomy (UPD) for 19 different chromosomes, defining imprinted DMRs as sites where the maternal and paternal methylation levels diverge significantly from the biparental mean. Using this approach we identified 77 DMRs, including nearly all those described in previous studies, in addition to 34 DMRs not previously reported. These include a DMR at TUBGCP5 within the recurrent 15q11.2 microdeletion region, suggesting potential parent-of-origin effects associated with this genomic disorder. We also observed a modest parental bias in DNA methylation levels at every CpG analyzed across approximately 1.9 Mb of the 15q11-q13 Prader-Willi/Angelman syndrome region, demonstrating that the influence of imprinting is not limited to individual regulatory elements such as CpG islands, but can extend across entire chromosomal domains. Using RNA-seq data, we detected signatures consistent with imprinted expression associated with nine novel DMRs. Finally, using a population sample of 4,004 blood methylomes, we define patterns of epigenetic variation at DMRs, identifying rare individuals with global gain or loss of methylation across multiple imprinted loci. Our data provide a detailed map of parental epigenetic bias in the human genome, providing insights into potential parent-of-origin effects.

Background and aims Prader–Willi syndrome (PWS) is characterized by a high incidence of altered glucose metabolism (AGM). However, epidemiological data on impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) are still discordant. Methods and results We performed a multicenter study based on 274 PWS patients [144 females, aged 20.3 ± 10.4 yrs (range: 8.1–50.1 years)] evaluating the prevalence for AGM in the entire group, and according to age (children 18 yrs), Body Mass Index (BMI = kg/m2), gender, genotypes (deletion or uniparental disomy for chromosome 15), and GH therapy (GHT) (untreated, previously or currently treated). Altogether, AGM was detected in 67 (24.4%) of patients (0.7% IFG, 10.2% IGT, 13.5% T2DM). The prevalence of AGM was correlated to age (p = 0.001), BMI (p = 0.001) and HOMA-IR (p = 0.001). However, gender, genotype, and GHT did not influence AGM development in univariate analysis. These data were confirmed as positive predictors when inserted in a multivariate analysis model. Conclusion This study is the first report on the prevalence of AGM in a large population of PWS. Overall, PWS subjects show a high prevalence of AGM that appears more common in obese and adult subjects. Our data confirm the main role of obesity on the individual metabolic risk clustering in PWS, and thus reinforce the concept that improvement in weight control remains the most important goal of any PWS treatment program.

Prader-Willi syndrome (PWS) is a rare neurodevelopmental and genetic disorder that is characterized by various expression of endocrine, cognitive and behavioral problems, among which a true obsession for food and a deficit of satiety that leads to hyperphagia and severe obesity. Neuropsychological studies have reported that PWS display altered social interactions with a specific weakness in interpreting social information and in responding to them, a symptom closed to that observed in autism spectrum disorders (ASD). Based on the hypothesis that atypical multisensory integration such as face and voice interactions would contribute in PWS to social impairment we investigate the abilities of PWS to process communication signals including the human voice. Patients with PWS recruited from the national reference center for PWS performed a simple detection task of stimuli presented in an uni-o or bimodal condition, as well as a voice discrimination task. Compared to control typically developing (TD) individuals, PWS present a specific deficit in discriminating human voices from environmental sounds. Further, PWS present a much lower multisensory benefits with an absence of violation of the race model indicating that multisensory information do not converge and interact prior to the initiation of the behavioral response. All the deficits observed in PWS were stronger for the subgroup of patients suffering from Uniparental Disomy, a population known to be more sensitive to ASD. Altogether, our study suggests that the deficits in social behavior observed in PWS derive at least partly from an impairment in deciphering the social information carried by voice signals, face signals, and the combination of both. In addition, our work is in agreement with the brain imaging studies revealing an alteration in PWS of the "social brain network" including the STS region involved in processing human voices.

Factors predicting the emotional well-being of adult siblings of those with developmental disability (DD) remain under-researched. In this study adult siblings of individuals with Down's syndrome (DS), autism (ASD), Prader-Willi syndrome (PWS) and those with DD but with unknown aetiology (DUA) were compared with each other and a closely-matched control group to ascertain if sibling disability type made a difference to anxiety and/or depression levels. Also considered was the interactive effect of gender, age, parental and sibling educational attainment levels, socio-economic status and birth order on anxiety and depression outcomes. With the exception of siblings of those with DS, adult siblings of those with ASD, PWS and DUA reported significantly higher levels of anxiety and depression than the control group. There were some predictive effects of the demographic variables upon anxiety and depression but none common to all disability types and no moderating effects of demographic factors were found. Consequently other solutions must be found as to why this important group of people have elevated rates of anxiety and depression in comparison to the general population.

Background: Prader-Willi syndrome (PWS), caused by a paternal defect on 15q11.2-q13, is the most common form of syndromic obesity. However, patients clinically diagnosed with PWS do not always show this defect on chromosome 15q and are therefore molecularly categorized as Prader Willi like (PWL). Deletions at 6q14.1-q16.3 encompassing MRAP2 and SIM1 were reported in some individuals with a PWL phenotype. In addition, a few mutations in SIM1 and MRAP2 were also previously identified in cohorts of obese individuals. Therefore, we decided to perform copy number variation analysis of the 6q14.1-6q16.3 region followed by mutation analysis of SIM1 and MRAP2 in a PWL cohort. Methods: A genome-wide microarray analysis was performed in a group of 109 PWL patients. Next, we screened 94 PWL patients for mutations in SIM1 and MRAP2 using high-resolution melting curve analysis and Sanger sequencing. Additionally, 363 obese children and adolescents were screened for mutations in MRAP2. Results: No gene harboring deletions were identified at the 6q14.1-q16.3 region in the 109 PWL patients. SIM1 mutation analysis resulted in the identification of one very rare nonsynonymous variant p.P352S (rs3734354). Another rare nonsynonymous variant, p.A40S, was detected in the MRAP2 gene. No variants were identified in the 363 obese individuals. Conclusions: In contrast to literature reports, no gene harboring deletions were identified in the SIM1 and MRAP2 regions in our PWL cohort. Secondly, taking into account their very low minor allele frequencies in public sequencing databases and the results of in silico prediction programs, further functional analysis of p.P352S found in SIM1 and p.A4OS found in MRAP2 is useful. This would provide further support for a possible role of SIM1 and MRAP2 in the pathogenesis of the PWL phenotype albeit in a limited number of patients. (C) 2016 Elsevier Inc. All rights reserved.

International audience; Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with a characteristic behavioural phenotype. A multidisciplinary approach to care is required to prevent multiple medical complications in individuals affected by PWS. The aim of this study was to describe the rehabilitation, medical care, educational and social support provided to school-aged French PWS patients with varying neuropsychological profiles. Data were obtained from a French multicentre study that included patients aged 4-20 years with diverse genetic syndromes. Nineteen PWS subjects with a mean age of 9.2 years were included. The mean full-scale intellectual quotient (IQ) was 58 (Wechsler scale). There were frequent dissociations between verbal and performance IQ that were not associated with a specific profile. We also observed lower autonomy and communication scores (5.3 years and 5.9 years equivalent, respectively, Vineland scale), the absence of hyperactivity (Conners scale), and the presence of behavioural abnormalities (CBCL scale). Multidisciplinary medical supervision was generally coordinated by the paediatric endocrinologist and did not always include follow-up with all of the recommended specialists, in particular with a paediatric psychiatrist. Analysis of multidisciplinary rehabilitation conducted in public and private-sector establishment revealed failings in psychological support, occupational therapy and dietary follow-up. Regarding education, most children younger than 10 years were in normal schools, while older individuals were often cared for in medico-social institutions. In conclusion, children and adolescents with PWS generally received appropriate care. Though there have been considerable improvements in the management of children with PWS, reference centres should continue reinforcing the coordination of multidisciplinary supervision.

Schizophrenia and bipolar disorder are common, severe, and disabling psychotic disorders, which are difficult to research. We argue that the genetically determined neurodevelopmental disorder Prader-Willi syndrome (PWS), which is associated with a high risk of affective psychotic illness, can provide a window into genetic mechanisms and associated neural pathways. People with PWS can all show non-psychotic psychopathology and problem behaviours, but the prevalence of psychotic illness differs markedly by genetic subtype; people with PWS due to chromosome 15 maternal uniparental disomy have higher prevalence of psychotic illness compared with patients with PWS due to 15q11-13 deletions of paternal origin. On the basis of this observation and the neural differences between genetic subtypes, we hypothesise that the combined effects of the absent expression of specific maternally imprinted genes at 15q11-13, and excess maternally imprinted or paternally expressed genes on chromosome 15, affect the γ-aminobutyric acid-glutamatergic pathways and associated neural networks that underpin mood regulation and sensory processing, resulting in psychotic illness. We propose a model of potential mechanisms of psychosis in PWS, which might be relevant in the general population, and should inform future research.