Prader-Willi Research Articles

Diagnosis of Two Unrelated Syndromes of Prader-Willi and Calpainopathy: Insight from Trio Whole Genome Analysis and Isodisomy Mapping.

An investigation for the co-occurrence of two unrelated genetic disorders of muscular dystrophy and Prader-Willi syndrome (PWS) (OMIM#176270) using joint whole genome sequencing (WGS). Trio WGS joint analysis was performed to investigate the genetic etiology in a proband with PWS, prolonged muscular hypotonia associated hyperCKemia, and early-onset obesity. The parents were unaffected. Results showed maternal isodisomy uniparental disomy (UPD) in chromosome 15, expanding from 15q11.2 to 15q22.2, including PWS regions at 15q11.2-15q13. Maternal heterodisomy was detected from 15q22.2 to 15q26.3. A pathogenic variant, NM_000070.3(CAPN3):c.550del (p.Thr184fs), was identified at 15q15.1 in a heterozygous state in the mother that was homozygous in the proband due to maternal isodisomy. This is the first study of the concurrent molecular etiology of PWS and calpainopathy (OMIM#253600) in the same patient. This report highlights the utility of joint analysis and the need for the assessment of autosomal recessive disease in regions of isodisomy in patients with complex and unexplained phenotypes.

The treatment of hyperphagia and obesity in Prader-Willi Syndrome

The treatment of hyperphagia and obesity in Prader-Willi Syndrome

Prader–Willi syndrome with atypical 15q deletion due to an unbalanced translocation between chromosomes 13 and 15

Prader–Willi syndrome with atypical 15q deletion due to an unbalanced translocation between chromosomes 13 and 15

Methods of Determining Energy Expenditure in Individuals with Prader-Willi Syndrome: A Systematic Literature Review.

Prader-Willi syndrome (PWS) is a rare disorder characterised by varying nutritional phases that occur throughout the lifespan, ranging from failure to thrive to hyperphagia. If uncontrolled, the imbalance between energy intake and expenditure results in obesity development and increased morbidity and mortality risk. Although measures of energy requirements for accurate nutrition assessment are vital, the evidence appears sparse and heterogeneous; hence, the aim of this review was to examine the available literature on energy expenditure predicted or measured using various methods in individuals with PWS. Studies were sought that presented methods and results on resting energy expenditure or basal metabolic rate. A narrative synthesis was completed to present the study characteristics and results. Methods of determining energy requirements included predictive equations and indirect calorimetry. Differences amongst ages, growth hormone therapy, fasting status, and measures in which results were presented were limitations to appropriately summarising and identifying trends in energy expenditure. Indirect calorimetry was identified as the most accurate method; however, it is not widely available in all settings. Further research is encouraged to support the development of valid and reliable predictive equations that will better inform and improve the efficiency of clinical practice in supporting people with PWS.

Mechanism of EHMT2-mediated genomic imprinting associated with Prader-Willi syndrome.

Prader-Willi Syndrome (PWS) is caused by loss of expression of paternally expressed genes in the human 15q11.2-q13 imprinting domain. A set of imprinted genes that are active on the paternal but silenced on the maternal chromosome are intricately regulated by a bipartite imprinting center (PWS-IC) located in the PWS imprinting domain. In past work, we discovered that euchromatic histone lysine N-methyltransferase-2 (EHMT2/G9a) inhibitors were capable of un-silencing PWS-associated genes by restoring their expression from the maternal chromosome. Here, in mice lacking the Ehmt2 gene, we document un-silencing of the imprinted Snrpn/Snhg14 gene on the maternal chromosome in the late embryonic and postnatal brain. Using PWS and Angelman syndrome patient derived cells with either paternal or maternal deletion of 15q11-q13, we have found that chromatin of maternal PWS-IC is closed and has compact 3D folding confirmation. We further show that a new and distinct noncoding RNA preferentially transcribed from upstream of the PWS-IC interacts with EHMT2 and forms a heterochromatin complex to silence gene expression of SNRPN in CIS on maternal chromosome. Taken together, these findings demonstrate that allele-specific recruitment of EHMT2 is required to maintain the maternal imprints. Our findings provide novel mechanistic insights and support a new model for imprinting maintenance of the PWS imprinted domain.

MAGEL2 (patho-)physiology and Schaaf-Yang syndrome.

Schaaf-Yang syndrome (SYS) is a complex neurodevelopmental disorder characterized by autism spectrum disorder, joint contractures, and profound hypothalamic dysfunction. SYS is caused by variants in MAGEL2, a gene within the Prader-Willi syndrome (PWS) locus on chromosome 15. In this review, we consolidate decades of research on MAGEL2 to elucidate its physiological functions. Moreover, we synthesize current knowledge on SYS, suggesting that while MAGEL2 loss-of-function seems to underlie several SYS and PWS phenotypes, additional pathomechanisms probably contribute to the distinct and severe phenotype observed in SYS. In addition, we highlight recent therapeutic advances and identify promising avenues for future investigation.

Prediction of LncRNA-protein Interactions Using Auto-Encoder, SE-ResNet Models and Transfer Learning.

Long non-coding RNA (lncRNA) plays a crucial role in various biological processes, and mutations or imbalances of lncRNAs can lead to several diseases, including cancer, Prader-Willi syndrome, autism, Alzheimer's disease, cartilage-hair hypoplasia, and hearing loss. Understanding lncRNA-protein interactions (LPIs) is vital for elucidating basic cellular processes, human diseases, viral replication, transcription, and plant pathogen resistance. Despite the development of several LPI calculation methods, predicting LPI remains challenging, with the selection of variables and deep learning structure being the focus of LPI research. We propose a deep learning framework called AR-LPI, which extracts sequence and secondary structure features of proteins and lncRNAs. The framework utilizes an auto-encoder for feature extraction and employs SE-ResNet for prediction. Additionally, we apply transfer learning to the deep neural network SE-ResNet for predicting small-sample datasets. Through comprehensive experimental comparison, we demonstrate that the AR-LPI architecture performs better in LPI prediction. Specifically, the accuracy of AR-LPI increases by 2.86% to 94.52%, while the F-value of AR-LPI increases by 2.71% to 94.73%. Our experimental results show that the overall performance of AR-LPI is better than that of other LPI prediction tools.

Prader-Willi Syndrome: A primer for school psychologists

Prader-Willi syndrome (PWS) is a rare neurogenetic syndrome that results in significant challenges in the school setting, often requiring a myriad of academic, social-emotional, and behavioral supports to maintain health and safety and academic success. This paper provides a primer for school psychologists, introducing the physiological, educational, and behavioral differences experienced by children with PWS. As the symptoms of PWS are widespread, the impacts of common physical and neurological differences on specific learning abilities, adaptive skills, and overall functioning in the classroom setting are discussed in detail. While PWS is a spectrum, and each child will experience symptoms and challenges differently, this article aims to provide a foundation for the development and facilitation of support services to assist educators in not only maintaining the health and safety of their students with PWS, but also in capitalizing on their strengths, and building a plan to help them succeed.

Efficacy of a Remote Play-Based Intervention for Children With Prader-Willi Syndrome.

The current study examines the efficacy of an 8-week pretend play intervention targeting social-cognitive abilities in children with Prader-Willi syndrome (PWS), ages 6-9. PWS is a rare disorder associated with various social, emotional, and cognitive challenges linked to pretend play impairments, and for which interventions are sparse. Nineteen children were quasi-randomized to receive the intervention or be part of a waitlist control group. Participants who received the intervention (n = 10) demonstrated significant improvements in various components of pretend play, most notably in organization of play, which may generalize to broader social-cognitive gains. These findings provide evidence of the intervention's efficacy in enhancing pretend play skills and related social-cognitive abilities during this critical period of development for children with PWS.

The motivations and methods behind sharing a pediatric Prader-Willi syndrome diagnosis.

Prader-Willi syndrome (PWS) is a genetic condition caused by a lack of paternally-expressed imprinted genes at chromosome 15q11.2-q13 and characterized by hyperphagia, behavioral challenges, and variable intellectual disability. Once a PWS diagnosis is established, sharing diagnosis information with an affected child can be challenging due to its early age of onset and diverse phenotype. This mixed-methods study aimed to evaluate how parents and guardians have shared a PWS diagnosis with their child and examine the motivating and influencing factors behind their disclosure. Parents and guardians of children with PWS aged at least 5 years completed a survey, and a select group completed an interview. A total of 51 surveys and 15 interviews were completed, with the majority of participants (n = 46; 90%) having shared at least some diagnosis information with their child. Parents and guardians were more likely to disclose if they self-reported a higher level of knowledge about PWS (p = 0.004) and if their child is currently older (p = 0.02) and/or has at least one sibling (p = 0.046). Interview analysis revealed 15 themes and 10 subthemes that illustrated parents' motivations, methods, and experiences with disclosure. This research provides information for others considering disclosure of PWS or another rare diagnosis with their child.

Investigating the correlation between genotype and phenotype in Prader-Willi syndrome: a study of 45 cases from Brazil

BackgroundPrader-Willi syndrome (PWS) is a genetic disorder characterized by abnormalities in the 15q11-q13 region. Understanding the correlation between genotype and phenotype in PWS is crucial for improved genetic counseling and prognosis. In this study, we aimed to investigate the correlation between genotype and phenotype in 45 PWS patients who previously underwent methylation-sensitive high-resolution melting (MS-HRM) for diagnosis.ResultsWe employed methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) and Sanger sequencing, along with collecting phenotypic data from the patients for comparison. Among the 45 patients, 29 (64%) exhibited a deletion of 15q11-q13, while the remaining 16 (36%) had uniparental disomy. No statistically significant differences were found in the main signs and symptoms of PWS. However, three clinical features showed significant differences between the groups. Deletion patients had a higher prevalence of myopia than those with uniparental disomy, as well as obstructive sleep apnea and an unusual skill with puzzles.ConclusionsThe diagnostic tests (MS-HRM, MS-MLPA, and Sanger sequencing) yielded positive results, supporting their applicability in PWS diagnosis. The study’s findings indicate a general similarity in the genotype-phenotype correlation across genetic subtypes of PWS.

Transcutaneous auricular vagus nerve stimulation to acutely reduce emotional vulnerability and improve emotional regulation in borderline personality disorder (tVNS-BPD): study protocol for a randomized, single-blind, sham-controlled trial

BackgroundBorderline personality disorder (BPD) is considered a disorder of emotion regulation resulting from the expression of a biologically determined emotional vulnerability (that is, heightened sensitivity to emotion, increased emotional intensity/reactivity, and a slow return to emotional baseline) combined with exposure to invalidating environments. Vagal tone has been associated with activity in cortical regions involved in emotion regulation and a lower resting state of vagal tone has been observed in BPD patients relative to healthy controls. Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has been shown to reduce temper outbursts in adults with Prader-Willi Syndrome, to enhance recognition of emotions in healthy students, and to improve depressive and anxiety symptoms. Furthermore, a single session of taVNS has been shown to acutely alter the recognition of facial expressions of negative valence in adolescents with MDD and increase emotion recognition in controls. However, the effect of taVNS on emotional vulnerability and regulation in individuals diagnosed with BPD has not been investigated. Our aims are to determine if taVNS is effective in acutely reducing emotional vulnerability and improve emotional regulation in BPD patients.MethodsForty-two patients will be randomized to a single session of taVNS or sham-taVNS while going through an affect induction procedure. It will consist of the presentation of one neutral and three negative affect-evoking 4-min-long videos in sequence, each of which is followed by a 4-min post-induction period during which participants will rate the quality and intensity of their current self-reported emotions (post-induction ratings) and the perceived effectiveness in managing their emotions during the video presentation. The rating of the current self-reported emotions will be repeated after every post-induction period (recovery ratings). Mixed models with individuals as random effect will be used to investigate the ratings at each stage of the study, taking into account the repeated measures of the same individuals at baseline, pre-induction, post-induction, and recovery.DiscussionThe study has potential to yield new insights into the role of vagal tone in emotion dysregulation in BPD and offer preliminary data on the effectiveness of taVNS as a possible non-invasive brain stimulation to treat a core symptom of BPD.Trial registrationClinicalTrials.gov NCT05892900. Retrospectively registered on Jun 07, 2023.

Genotype-phenotype characteristics of 57 patients with Prader-Willi syndrome: a single-center experience from Turkey.

Prader-Willi syndrome (PWS) is a rare and complex genetic disorder caused by the loss of expression of the paternal copy of the imprinted genes on chromosome 15q11-q13. A variety of findings have been reported on the phenotypic differences between the genetic subtypes of PWS. This article compares the clinical findings of 57 PWS patients by genetic subtype and explores possible associations in this context. Methylation‑specific multiplex ligation-dependent probe amplification and single nucleotide polymorphism microarrays were used to diagnose deletion and uniparental disomy (UPD). For phenotype-genotype correlation, clinical data were collected and genetic subgroups were compared statistically, and P < 0.05 was considered to indicate statistical significance. These 57 patients consisted of 15 type I deletions, 20 type II deletions, six atypic deletions, 11 heterodisomy UPD, four isodisomy UPD, and one translocation-type PWS. All patients had hypotonia, poor neonatal sucking, and feeding difficulties during infancy. Other PWS-related clinical findings, such as speech articulation problems (85.9%), sleep apnea (77.2%), normal birth length (71.9%), small hands/feet (71.9%), childhood polyphagia (57.9%), clinodactyly (56.1%), thick viscous saliva (54.4%), and behavioral problems (50.9%) were observed at varying rates with no statistical difference between genetic subtypes in general. This study highlights the phenotype-genotype associations on PWS from a cohort of Turkish pediatric patients as a single-center experience.

Loss-of-function G6PD variant moderated high-fat diet-induced obesity, adipocyte hypertrophy, and fatty liver in male rats

Obesity is a major risk factor for liver and cardiovascular diseases. However, obesity-driven mechanisms that contribute to the pathogenesis of multiple organ diseases are still obscure and treatment is inadequate. We hypothesized that increased glucose-6-phosphate dehydrogenase (G6PD), the key rate-limiting enzyme in the pentose shunt, is critical in evoking metabolic reprogramming in multiple organs and is a significant contributor to the pathogenesis of liver and cardiovascular diseases. G6PD is induced by carbohydrate-rich diet and insulin. Long-term (8 months) high-fat diet (HFD) feeding increased body weight and elicited metabolic reprogramming in visceral fat, liver, and aorta, of the wild-type rats. In addition, HFD increased inflammatory chemokines in visceral fat. Interestingly, CRISPR-edited loss-of-function Mediterranean G6PD variant (G6PDS188F) rats, which mimic human polymorphism, moderated HFD-induced weight gain and metabolic reprogramming in visceral fat, liver, and aorta. The G6PDS188F variant prevented HFD-induced CCL7 and adipocyte hypertrophy. Furthermore, the G6PDS188F variant increased Magel2 – a gene encoding circadian clock-related protein that suppresses obesity associated with Prader-Willi syndrome – and reduced HFD-induced non-alcoholic fatty liver. Additionally, the G6PDS188F variant reduced aging-induced aortic stiffening. Our findings suggest G6PD is a regulator of HFD-induced obesity, adipocyte hypertrophy, and fatty liver.

Psychiatric care for people with Prader-Willi syndrome-characteristics, needs and barriers.

Prader-Willi syndrome (PWS) is commonly associated with intellectual disability, but also with a specific behavioural phenotype and a high predisposition to psychiatric comorbidity. This study examines the psychiatric care situation of people with PWS. A structured online questionnaire was administered to carers of people with PWS living in Germany, asking about demographic, diagnostic and treatment parameters as well as personal experiences. Of 77 people with PWS, 44.2% had at least one psychiatric comorbid diagnosis. The main reasons for seeking psychiatric care were emotional outbursts and aggressive behaviour. 34.9% reported that they were currently seeking psychiatric care without success. However, 32.5% of PWS had been treated with psychotropic medication, mainly antipsychotics. Psychiatric comorbidity appears to be undertreated in PWS, especially in the ambulatory setting. Uncertainty among mental health care providers may also lead to frequent off-label use of psychotropic medications.

Secondary diabetes due to different etiologies: Four case reports

BACKGROUND As research on diabetes continues to advance, more complex classifications of this disease have emerged, revealing the existence of special types of diabetes, and many of these patients are prone to misdiagnosis and underdiagnosis, leading to treatment delays and increased health care costs. The purpose of this study was to identify four causes of secondary diabetes. CASE SUMMARY Secondary diabetes can be caused by various factors, some of which are often overlooked. These factors include genetic defects, autoimmune disorders, and diabetes induced by tumours. This paper describes four types of secondary diabetes caused by Williams–Beuren syndrome, Prader–Willi syndrome, pituitary adenoma, and IgG4-related diseases. These cases deviate significantly from the typical progression of the disease due to their low incidence and rarity, often leading to their neglect in clinical practice. In comparison to regular diabetes patients, the four individuals described here exhibited distinct characteristics. Standard hypoglycaemic treatments failed to effectively control the disease. Subsequently, a series of examinations and follow-up history confirmed the diagnosis and underlying cause of diabetes. Upon addressing the primary condition, such as excising a pituitary adenoma, providing glucocorticoid supplementation, and implementing symptomatic treatments, all patients experienced a considerable decrease in blood glucose levels, which were subsequently maintained within a stable range. Furthermore, other accompanying symptoms improved. CONCLUSION Rare diseases causing secondary diabetes are often not considered in the diagnosis of diabetes. Therefore, it is crucial to conduct genetic tests, antibody detection and other appropriate diagnostic measures when necessary to facilitate early diagnosis and intervention through proactive and efficient management of the underlying condition, ultimately improving patient outcomes.

Prader-Willi syndrome: guidance for children and transition into adulthood.

Prader-Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues, especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.

Relationship of thyroid function with genetic subtypes and treatment with growth hormone in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is the most common genetic syndrome with obesity and results from loss of expression of paternally inherited genes on chromosome 15q11-q13 by a variety of mechanisms which include large deletions (70%-75%), maternal uniparental disomy (UPD) (20%-30%), and imprinting defects (2%-5%) or balanced translocations. Individuals often have a characteristic behavior disorder with mild intellectual disability, infantile hypotonia associated with poor sucking, short stature, and obesity. PWS is characterized by hypothalamic-pituitary axis dysfunction with growth hormone (GH) deficiency, hypogonadism, and several other hormonal deficiencies resulting in short stature, centrally driven excessive appetite (hyperphagia), central obesity, cryptorchidism, and decreased lean body mass. In this study, we determined and sought differences in the incidence of thyroid abnormalities among the common genetic subtypes in a cohort of 52 subjects with PWS because there was limited literature available. We also sought the effects of growth hormone (GH) treatment on the thyroid profile. Fifty-two subjects with a genetically confirmed diagnosis of PWS were included in this study at the University of California, Irvine. Blood samples for baseline thyroxine stimulating hormone (TSH) and free thyroxine (fT4) levels were obtained in the morning after an overnight fast for 8-12 h. Statistical analyses were performed with SPSS (SPSS Inc., 21.0). Mean values were analyzed by one-way ANOVA, and student's t-test and statistical significance were set at p < 0.05. The subjects included 26 males and 26 females with an age range of 3-38 years. There were 29 subjects with chromosome 15q11-q13 deletions and 23 with UPD; 28 were GH treated currently or in the past, and 24 never received GH. There was no significant difference in age or body mass index (BMI) (kg/m2) between GH-treated versus non-GH-treated groups. BMI was higher in the deletion group compared to the UPD group (p = 0.05). We identified two individuals who were clinically diagnosed and treated for hypothyroidism, one of whom was on GH supplements. We identified two additional individuals with subclinical hypothyroidism who were not on GH treatment, giving a frequency of 7.6% (4/52) in this cohort of patients. We did not find significant differences in thyroid function (TSH) in the deletion versus UPD groups. We found significant differences in thyroid function, however, between GH-treated and non-GH-treated groups. The mean TSH was lower (2.25 ± 1.17 uIU/M, range 0.03-4.92 uIU/M versus 2.80 ± 1.44 uIU/M, range 0.55-5.33 uIU/M respectively, p = 0.046), and the free T4 levels were significantly higher (1.13 ± 0.70 and 1.03 ± 0.11 ng/dL, respectively, p = 0.05) in the GH-treated individuals compared to non-GH-treated individuals. In this cohort of subjects with PWS, we identified two previously diagnosed individuals with hypothyroidism and two individuals with subclinical hypothyroidism (4/52, 7.6%), three of whom were not receiving GH treatment. We did not find any significant differences in thyroid function between molecular subtypes; however, we found that euthyroid status (lower TSH levels and higher free T4 levels) was significantly higher in individuals who were treated with GH compared to the untreated group. We recommend that individuals with PWS should be screened regularly for thyroid deficiency and start treatment early with GH in view of the potentially lower incidence of thyroid deficiency.

Quality of Life for Adults with Prader-Willi Syndrome in Residential Group Homes.

Background: Strict regimens of restricted caloric intake and daily physical exercise are life-saving in Prader-Willi syndrome (PWS) but are extremely challenging in home environments. PWS-specialized hostels (SH) succeed in preventing morbid obesity and in coping with behavioral disorders; however, effects of restricted living environments on quality of life (QOL) have not been described. Evidence on QOL is critical for clinicians involved in placement decisions. Methods: We examined the impact of living in SH versus at home or in non-specialized hostels (H and NSH) on QOL, behavior, and health parameters. All 58 adults (26 males) followed-up in the National Multidisciplinary Clinic for PWS were included: 33 resided in SH, 18 lived at home, and 7 lived in NSH. Questionnaires were administered to primary caregivers to measure QOL, and data were obtained from the medical records. Results: The H and NSH group were compared with those for adults in SH. Despite strict diet and exercise regimens, QOL was similar for both groups. Eight-year follow-up showed that food-seeking behavior decreased in SH but increased in H and NSH. BMI, cholesterol, and triglyceride levels were lower in SH. Conclusion: Our results suggest that living in SH is associated with benefits for physical health and behavior without negatively affecting QOL.

Role of projective psychological tests in patients with Prader-Willi syndrome.

The purpose of this study was to evaluate the usefulness and relevance of projective techniques such as house-tree-person (HTP) and family in individuals with Prader-Willi syndrome (PWS), who have a limited ability to identify and verbalize emotions and express them often using behaviors. We included individuals with genetic confirmation of PWS immersed in a regular transdisciplinary treatment in an institution dedicated to rare diseases. All individuals were evaluated using the HTP and family projective techniques. These instruments are commonly administered to the general population and, in this case, to people with mild to moderate intellectual disabilities, including difficulties in their communication abilities. A total of 25 individuals with PWS between 10 and 41 years old (15 men and 10 women) were included. We identified the presence of graphic indicators corresponding to the behavioral phenotype of individuals with PWS, such as anxiety, stubbornness, emotional lability, difficulty in achieving adequate externalization and identification of emotions, impulsivity, aggressive traits, poor social skills, need for support and interaction, low self-concept, and compulsive behaviors. In the present study, we demonstrated the usefulness of graphic techniques to elucidate aspects of behavior, emotions, and thoughts that individuals with PWS cannot formulate due to expression and communication difficulties.