Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update

A Comprehensive Review of Syndromic Forms of Obesity: Genetic Etiology, Clinical Features and Molecular Diagnosis

Syndromic obesity refers to obesity occurring with additional clinical findings, such as intellectual disability/developmental delay, dysmorphic features, and congenital malformations. PURPOSE OF REVIEW: To present a narrative review regarding the genetic etiology, clinical description, and molecular diagnosis of syndromic obesity, which is a rare condition with high phenotypic variability and genetic heterogeneity. The following syndromes are presented in this review: Prader-Willi, Bardet-Biedl, Pseudohypoparathyroidism, Alström, Smith-Magenis, Cohen, Temple, 1p36 deletion, 16p11.2 microdeletion, Kleefstra, SIM1-related, Börjeson-Forssman-Lehmann, WAGRO, Carpenter, MORM, and MYT1L-related syndromes. RECENT FINDINGS: There are three main groups of mechanisms for syndromic obesity: imprinting, transcriptional activity regulation, and cellular cilia function. For molecular diagnostic, methods of genome-wide investigation should be prioritized over sequencing of panels of syndromic obesity genes. In addition, we present novel syndromic conditions that need further delineation, but evidences suggest they have a higher frequency of obesity. The etiology of syndromic obesity tends to be linked to disrupted neurodevelopment (central) and is associated with a diversity of genes and biological pathways. In the genetic investigation of individuals with syndromic obesity, the possibility that the etiology of the syndromic condition is independent of obesity should be considered. The accurate genetic diagnosis impacts medical management, treatment, and prognosis, and allows proper genetic counseling.

Tackling access and payer barriers for growth hormone therapy in Saudi Arabia: a consensus statement for the Saudi Working Group for Pediatric Endocrinology

Prompt diagnosis and early treatment are key goals to optimize the outcomes of children with growth hormone deficiency (GHD) and attain the genetically expected adult height. Nonetheless, several barriers can hinder prompt diagnosis and treatment of GHD, including payer-related issues. In Saudi Arabia, moderate-to-severe short stature was reported in 13.1 and 11.7 % of healthy boys and girls, respectively. Several access and payer barriers can face pediatric endocrinologists during the diagnosis and treatment of GHD in Saudi Arabia. Insurance coverage policies can restrict access to diagnostic tests for GHD and recombinant human growth hormone (rhGH) due to their high costs and lack of gold-standard criteria. Some insurance policies may limit the duration of treatment with rhGH or the amount of medication covered per month. This consensus article gathered the insights of pediatric endocrinologists from Saudi Arabia to reflect the access and payer barriers to the diagnostic tests and treatment options of children with short stature. We also discussed the current payer-related challenges endocrinologists face during the investigations of children with short stature. The consensus identified potential strategies to overcome these challenges and optimize patient management.

Hao-Fountain syndrome: 32 novel patients reveal new insights into the clinical spectrum

Hao-Fountain syndrome (HAFOUS, OMIM: #616863) is a neurodevelopmental disorder caused by pathogenic variants in the gene USP7 coding for USP7, a protein involved in several crucial cellular homeostatic mechanisms and the recently described MUST complex. The phenotype of HAFOUS is insufficiently understood, yet there is a great need to better understand the spectrum of disease, genotype-phenotype correlations, and disease trajectories. We now present a larger cohort of 32 additional individuals and provide further clinical information about six previously reported individuals. A questionnaire-based study was performed to characterize the phenotype of Hao-Fountain syndrome more clearly, to highlight new traits, and to better distinguish the disease from related neurodevelopmental disorders. In addition to confirming previously described features, we report hyperphagia and increased body weight in a subset of individuals. HAFOUS patients present an increased rate of birth complications, congenital anomalies, and abnormal pain thresholds. Speech impairment emerges as a potential hallmark of Hao-Fountain syndrome. Cognitive testing reports reveal borderline intellectual functioning on average, although some individuals score in the range of intellectual disability. Finally, we created a syndrome-specific severity score. This score neither indicates a sex- nor age-specific difference of clinical severity, yet highlights a more severe outcome when amino acid changes colocalize to the catalytic domain of the USP7 protein.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

BACKGROUND

Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication.

METHODS

Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication.

RESULTS

The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis.

CONCLUSIONS

Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

Prader-Willi Syndrome: The More We Know, the Less We Know

Prader-Willi syndrome (PWS) is a complex genetic neurodevelopmental disorder with multisystem impact and a unique behavior profile that evolves over the life span. Beyond the primary care needs of all children and adults, the unique medical concerns and management needs of those with PWS are best served in a multidisciplinary academic center. Our PWS center has provided care for individuals with PWS and their families since 1981. Our growth hormone studies contributed to growth hormone supplementation becoming standard of care in this country. Here, in collaboration with the primary care provider, early childhood intervention programs, schools and local parent organizations, solid, patient-centered care for affected individuals and their families can be provided across the life-span. The purpose of this article is to provide a brief overview of PWS and the attendant medical and behavior management challenges attendant to the disorder.

The outcomes of growth hormone therapy in the obstructive sleep apnea parameters of Prader-Willi syndrome patients: a systematic review

PURPOSE

Prader-Willi syndrome is a serious genetic condition, capable of causing endocrinological imbalance, which has as one of its main treatments the growth hormone therapy. However, this therapy still causes some uncertainty concerning its effects on the respiratory parameters of those patients, especially in cases of obstructive sleep apnea, therefore, presenting a need for the analysis of the relationship between the therapy and the otolaryngologic condition.

METHODS

A systematic review following the PRISMA model was developed, with searches for keywords made in the databases PubMed (MEDLINE), Scopus, and Web of Science and registration in the PROSPERO platform (CRD42023404250).

RESULTS

Three randomized controlled trials were considered eligible for inclusion in the review. None of the studies demonstrated statistically significant modifications in the obstructive sleep apnea parameters of Prader-Willi patients related to the growth hormone administration.

CONCLUSIONS

Growth hormone therapy is safe for Prader-Willi syndrome patients when analyzing their obstructive sleep apnea parameters.

Behavioral changes in patients with Prader-Willi syndrome receiving diazoxide choline extended-release tablets compared to the PATH for PWS natural history study

BACKGROUND

Prader-Willi syndrome (PWS) is a rare neurobehavioral-metabolic disease caused by the lack of paternally expressed genes in the chromosome 15q11-q13 region, characterized by hypotonia, neurocognitive problems, behavioral difficulties, endocrinopathies, and hyperphagia resulting in severe obesity if energy intake is not controlled. Diazoxide choline extended-release (DCCR) tablets have previously been evaluated for their effects on hyperphagia and other behavioral complications of people with PWS in a Phase 3 placebo-controlled study of participants with PWS, age 4 and older with hyperphagia (C601) and in an open label extension study, C602.

METHODS

To better understand the longer-term impact of DCCR, a cohort from PATH for PWS, a natural history study that enrolled participants with PWS age 5 and older, who met the C601 age, weight and baseline hyperphagia inclusion criteria and had 2 hyperphagia assessments ≥ 6 months apart, were compared to the C601/C602 cohort. Hyperphagia was measured using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT, range 0-36). The primary analysis used observed values with no explicit imputation of missing data. A sensitivity analysis was conducted in which all missing HQ-CT assessments in the C601/C602 cohort were assigned the highest possible value (36), representing the worst-case scenario. Other behavioral changes were assessed using the Prader-Willi Syndrome Profile questionnaire (PWSP).

RESULTS

Relative to the PATH for PWS natural history study cohort, the DCCR-treated C601/C602 cohort showed significant improvements in HQ-CT score at 26 weeks (LSmean [SE] -8.3 [0.75] vs. -2.5 [0.43], p < 0.001) and 52 weeks (LSmean [SE] -9.2 [0.77] vs. -3.4 [0.47], p < 0.001). The comparison between the cohorts remained significant in the worst-case imputation sensitivity analysis. There were also significant improvements in all domains of the PWSP at 26 weeks (all p < 0.001) and 52 weeks (all p ≤ 0.003) for C601/C602 participants compared to the PATH for PWS participants.

CONCLUSION

Long-term administration of DCCR to people with PWS resulted in changes in hyperphagia and other behavioral complications of PWS that are distinct from the natural history of the syndrome as exemplified by the cohort from PATH for PWS. The combined effects of administration of DCCR should reduce the burden of the syndrome on the patient, caregivers and their families, and thereby may benefit people with PWS and their families.

TRIAL REGISTRATION

Clinical study C601 was originally registered on ClinicalTrials.gov on February 22, 2018 (NCT03440814). Clinical study C602 was originally registered on ClinicalTrials.gov on October 22, 2018 (NCT03714373). PATH for PWS was originally registered on ClinicalTrials.gov on October 24, 2018 (NCT03718416).

Laryngeal clefts in Prader-Willi syndrome: Feeding difficulties and aspiration not always caused by hypotonia

Feeding difficulties, aspiration, and failure to thrive in infancy are commonly seen in patients with Prader-Willi Syndrome (PWS) and attributed to hypotonia. Patients with PWS and laryngeal clefts were identified by review of medical records at three tertiary care children's hospitals between 2017 and 2022. We present three patients with PWS with feeding difficulties who were also found to have laryngeal clefts which likely contributed to their feeding difficulties. Additional factors such as airway anomalies should be considered in patients with PWS, especially when swallowing dysfunction, dysphagia, or abnormal swallow evaluations are present.

Exploring the Multifaceted Landscape of Pediatric Obstructive Sleep Apnea: Insights into Prevalence, Severity, and Coexisting Conditions

Background

Pediatric obstructive sleep apnea (OSA) is a multifaceted disorder marked by recurrent upper airway obstruction during sleep, often coexisting with various medical conditions. This study, aimed to comprehensively analyze the Multifaceted Landscape of Pediatric Insights into Prevalence, Severity, and Coexisting Conditions. With a sample of 1928 participants, our study sought to determine the prevalence, severity, and associations between OSA and diverse conditions.

Methods

Conducted retrospectively from February 2019 to April 2023, the study included pediatric patients. Data were collected through electronic health records, involving clinical assessments, medical histories, and diagnostic tests to establish OSA and coexisting condition diagnoses. Relationships between sleep parameters, apnea types, and severity indices were evaluated.

Results

High OSA prevalence was evident across age groups, with severity peaking between 3 to 12 years. Among the participants, coexisting conditions included allergic rhinitis (59.6%), tonsillar hypertrophy (49.7%), adenoid hypertrophy (28.4%), and obesity (15.3%). Analysis revealed intriguing relationships between different sleep parameters and apnea types. Notable associations were observed between Obstructive Apnea (OA) and Central Apnea (CA), and Mixed Apnea (MA) displayed associations with both OA and CA. Hypopnea correlated directly with the Apnea-Hypopnea Index (AHI), reflecting its role in OSA severity.

Conclusion

This study provides a comprehensive understanding of the intricate dynamics between pediatric OSA and coexisting conditions. The prevalence of OSA and its coexistence with various conditions underscore the need for comprehensive evaluation and management strategies. By revealing associations between different sleep parameters and apnea types, the study emphasizes the complexity of OSA diagnosis and management. These findings hold the potential to enhance clinical approaches, ultimately leading to improved care and outcomes for affected children.

Bardet-Biedl syndrome: A clinical overview focusing on diagnosis, outcomes and best-practice management

Bardet-Biedl syndrome (BBS) is a genetic disorder characterized by early-onset obesity, polydactyly, genital and kidney anomalies, developmental delay and vision loss due to rod-cone dystrophy. BBS is an autosomal recessive disorder with >20 implicated genes. The genotype-phenotype relationship in BBS is not clear, and there may be additional modifying factors. The underlying mechanism is dysfunction of primary cilia. In BBS, receptor trafficking in and out of the cilia is compromised, affecting multiple organ systems. Along with early-onset obesity, hyperphagia is a prominent symptom and contributes significantly to clinical morbidity and caregiver burden. While there is no cure for BBS, setmelanotide is a new pharmacotherapy approved for treatment of obesity in BBS. The differential diagnosis for BBS includes other ciliopathies, such as Alstrom syndrome, and other genetic obesity syndromes, such as Prader-Willi syndrome. Careful clinical history and genetic testing can help determine the diagnosis and a multidisciplinary team is necessary to guide clinical management.

Behavioral and Psychiatric Disorders in Syndromic Autism

Syndromic autism refers to autism spectrum disorder diagnosed in the context of a known genetic syndrome. The specific manifestations of any one of these syndromic autisms are related to a clinically defined genetic syndrome that can be traced to certain genes and variants, genetic deletions, or duplications at the chromosome level. The genetic mutations or defects in single genes associated with these genetic disorders result in a significant elevation of risk for developing autism relative to the general population and are related to recurrence with inheritance patterns. Additionally, these syndromes are associated with typical behavioral characteristics or phenotypes as well as an increased risk for specific behavioral or psychiatric disorders and clinical findings. Knowledge of these associations helps guide clinicians in identifying potentially treatable conditions that can help to improve the lives of affected patients and their families.

Early psychomotor development and growth hormone therapy in children with Prader-Willi syndrome: a review

Prader-Willi syndrome (PWS) is a rare genetic disorder caused by the loss of imprinted gene expression on the paternal chromosome 15q11-q13. PWS is characterized by varying degrees of early psychomotor developmental deficits, primarily in cognition, language, and motor development. This review summarizes the early mental cognitive development, language development, and motor development in patients with PWS, compares the correlation of genotype with phenotype, and provides an update regarding the effects and concerns related to potential main side effects of treatment with recombinant human growth hormone on early psycho-cognitive and motor function development along with the linear growth and body composition of children with PWS.Conclusion: Early psychomotor development is strongly correlated with the prognosis of patients with PWS; moreover, current studies support that the initiation of interventions at an early age can exert significant beneficial effects on enhancing the cognitive and linguistic development of patients with PWS and allow them to "catch up" with motor development.  What is Known: • Prader-Willi syndrome is a rare genetic disorder characterized by multisystem damage, and children with Prader-Willi syndrome are typically characterized by early developmental delays, specifically in the areas of cognitive and motor development. • Recombinant human growth hormone therapy is the only medical treatment approved for Prader-Willi syndrome. What is New: • Extensive presentation of psycho-cognitive and motor development features and genotype-phenotype correlation in children with Prader-Willi syndrome.  • The effects of growth hormone on early psychomotor development in children with Prader-Willi syndrome were thoroughly reviewed, including their short- and long-term outcomes and any associated adverse effects.

Pharmacogenomics for Prader-Willi syndrome: caregiver interest and planned utilization

Aim: The study aim was to determine caregiver interest and planned utilization of pharmacogenomic (PGx) results for their child with Prader-Willi syndrome. Methods: Caregivers consented to PGx testing for their child and completed a survey before receiving results. Results: Of all caregivers (n = 48), 93.8% were highly interested in their child's upcoming PGx results. Most (97.9%) planned to share results with their child's medical providers. However, only 47.9% of caregivers were confident providers would utilize the PGx results. Conclusion: Caregivers are interested in utilizing PGx but are uncertain providers will use these results in their child's care. More information about provider comfort with PGx utilization is needed to understand how PGx education would benefit providers and ultimately patients with PGx results.

Complex Cardiovascular Morbidities in Prader-Willi Syndrome: A Multidisciplinary Approach

This case emphasizes the complexity of Prader-Willi syndrome (PWS), the need for a collaborative approach from specialists, and a closer look at the various cardiovascular complexities associated with this syndrome. While current treatments focus on managing symptoms, ongoing genetic research offers hope for more favorable outcomes. Further studies are crucial to gauge the effectiveness of these treatments for PWS patients. We detail a patient with a complex medical history of PWS, further complicated by congenital heart disease with Eisenmenger's syndrome, diabetes mellitus, pulmonary hypertension, venous insufficiency, hypothyroidism, and hyperlipidemia. Reported in this study is a compilation of clinical data as well as suggestions from several medical specialists in applying a multifaceted approach to treatment, significantly emphasizing the need for interdisciplinary care and management of patients experiencing a combination of various medical issues with an emphasis on cardiovascular complications.

Comparative analysis of emotional facial expression recognition and empathy in children with prader-willi syndrome and autism spectrum disorder

BACKGROUND

Prader-Willi Syndrome (PWS) is a rare neurodevelopmental disorder that is often comorbid with Autism Spectrum Disorder (ASD). Due to the close association between these two conditions, and recognizing that Theory of Mind (ToM) is related to social behaviors in ASD, there is a growing interest in studying the reciprocity of social communication between these two groups.

METHOD

The primary objective of this study was to compare how children (n = 45) with PWS (n = 15), ASD (n = 15), and a control group (n = 15) respond to emotion recognition of facial expressions and empathy, which are both concepts related to ToM. The study utilized two tools named FEEL and Deusto-e-Motion 1.0. We also evaluated the Working Memory index of the WISC-IV scale, the Social Perception domain of the NEPSY-II battery, and the SCQ in both clinical groups.

RESULTS

Our findings suggest that individuals with PWS exhibit lower accuracy in recognizing facial expressions and empathy compared to the control group. Both clinical groups exhibited a delayed reaction time compared to the control group. Children with PWS display difficulties in recognizing emotions of disgust and surprise. In terms of cognitive empathy, children with PWS showed a greater inclination to respond to disgust as compared to children with ASD.

CONCLUSIONS

This study represents the initial stage in comprehending the emotional and empathetic abilities of children with PWS and ASD. The findings can provide valuable insights for developing future interventions.

The Pivotal Role of Oxytocin's Mechanism of Thermoregulation in Prader-Willi Syndrome, Schaaf-Yang Syndrome, and Autism Spectrum Disorder

Oxytocin (Oxt) regulates thermogenesis, and altered thermoregulation results in Prader-Willi syndrome (PWS), Schaaf-Yang syndrome (SYS), and Autism spectrum disorder (ASD). PWS is a genetic disorder caused by the deletion of the paternal allele of 15q11-q13, the maternal uniparental disomy of chromosome 15, or defects in the imprinting center of chromosome 15. PWS is characterized by hyperphagia, obesity, low skeletal muscle tone, and autism spectrum disorder (ASD). Oxt also increases muscle tonicity and decreases proteolysis while PWS infants are hypotonic and require assisted feeding in early infancy. This evidence inspired us to merge the results of almost 20 years of studies and formulate a new hypothesis according to which the disruption of Oxt's mechanism of thermoregulation manifests in PWS, SYS, and ASD through thermosensory abnormalities and skeletal muscle tone. This review will integrate the current literature with new updates on PWS, SYS, and ASD and the recent discoveries on Oxt's regulation of thermogenesis to advance the knowledge on these diseases.

Diazoxide choline extended-release tablet in people with Prader-Willi syndrome: results from long-term open-label study

OBJECTIVE

This study assessed the effect of 1-year administration of diazoxide choline extended-release tablet (DCCR) on hyperphagia and other complications of Prader-Willi syndrome (PWS).

METHODS

The authors studied 125 participants with PWS, age ≥ 4 years, who were enrolled in the DESTINY PWS Phase 3 study and who received DCCR for up to 52 weeks in DESTINY PWS and/or its open-label extension. The primary efficacy endpoint was Hyperphagia Questionnaire for Clinical Trials (HQ-CT) score. Other endpoints included behavioral assessments, body composition, hormonal measures, and safety.

RESULTS

DCCR administration resulted in significant improvements in HQ-CT (mean [SE] -9.9 [0.77], p < 0.0001) and greater improvements in those with more severe baseline hyperphagia (HQ-CT > 22). Improvements were seen in aggression, anxiety, and compulsivity (all p < 0.0001). There were reductions in leptin, insulin, and insulin resistance, as well as a significant increase in adiponectin (all p < 0.004). Lean body mass was increased (p < 0.0001). Disease severity was reduced as assessed by clinician and caregiver (both p < 0.0001). Common treatment-emergent adverse events included hypertrichosis, peripheral edema, and hyperglycemia. Adverse events infrequently resulted in discontinuation (7.2%).

CONCLUSIONS

DCCR administration to people with PWS was well tolerated and associated with broad-ranging improvements in the syndrome. Sustained administration of DCCR has the potential to reduce disease severity and the burden of care for families.

Effect of semaglutide on weight loss and glycaemic control in patients with Prader-Willi Syndrome and type 2 diabetes

Prader-Willi Syndrome (PWS) is the most common genetic cause of obesity, occurring in approximately 1 in 15,000 newborns. It results from the lack of expression of genes on the paternal allele of the chromosomal region 15q-11q13 (65-75% due to type 1 or type 2 deletion). Individuals with PWS experience associated symptoms such as hypotonia, hyperphagia, and early-onset obesity (before 5 years of age). Around 20% of adults with PWS also develop type 2 diabetes. Previous studies have shown the beneficial effects of GLP1-RA medications, such as exenatide and liraglutide, in treating type 2 diabetes in PWS. However, there is limited information available on the use of semaglutide in PWS. This study aimed to evaluate the effects of semaglutide on weight loss and glycaemic control in four patients with PWS and type 2 diabetes associated with obesity. The patients were started on weekly subcutaneous progressive doses of semaglutide.

A comprehensive review of genetic causes of obesity

BACKGROUND

Obesity is a multifactorial chronic disease with a high, increasing worldwide prevalence. Genetic causes account for 7% of the cases in children with extreme obesity.

DATA SOURCES

This narrative review was conducted by searching for papers published in the PubMed/MEDLINE, Embase and SciELO databases and included 161 articles. The search used the following search terms: "obesity", "obesity and genetics", "leptin", "Prader-Willi syndrome", and "melanocortins". The types of studies included were systematic reviews, clinical trials, prospective cohort studies, cross-sectional and prospective studies, narrative reviews, and case reports.

RESULTS

The leptin-melanocortin pathway is primarily responsible for the regulation of appetite and body weight. However, several important aspects of the pathophysiology of obesity remain unknown. Genetic causes of obesity can be grouped into syndromic, monogenic, and polygenic causes and should be assessed in children with extreme obesity before the age of 5 years, hyperphagia, or a family history of extreme obesity. A microarray study, an analysis of the melanocortin type 4 receptor gene mutations and leptin levels should be performed for this purpose. There are three therapeutic levels: lifestyle modifications, pharmacological treatment, and bariatric surgery.

CONCLUSIONS

Genetic study technologies are in constant development; however, we are still far from having a personalized approach to genetic causes of obesity. A significant proportion of the affected individuals are associated with genetic causes; however, there are still barriers to its approach, as it continues to be underdiagnosed. Video Abstract (MP4 1041807 KB).

Mental health impact on primary and secondary Prader-Willi syndrome caregivers

INTRODUCTION

Caring for individuals with rare diseases can be challenging and represent a burden. Nevertheless, this has been scarcely explored in Prader-Willi syndrome (PWS). Therefore, we sought to explore the psychological impact of caregiving, as well as the differences between main caregivers and other family members.

METHODS

Different evaluation tools and scales were used taking into consideration the impact on caregivers. The scales were administered to those relatives who are immersed in the usual dynamics of the patient, differentiating between the main caregiver and other relatives living in the family home.

RESULTS

A total of 33 families of patients with genetic confirmation of PWS were included. In this survey, 32% of primary caregivers reported a high probability of anxiety, compared with 19% of non-primary caregivers (p = 0.27). Concerning depression, 40% of primary caregivers related possible or probable cases of depression compared with non-primary caregivers 13% (p = 0.04). Regarding caregiver burden evaluated using the Zarit scale, 61% of the main caregivers presented high levels of overload, compared with 29% of the other relatives (p = 0.005). Family functioning evaluated using the APGAR scale showed a total lower response from primary caregivers, but no statistically relevant results were found [25.4 ± 6.7 vs. 26.0 ± 8.2 (p = 0.72)].

CONCLUSION

In this study, we observed that caring for people with PWS can have a significant effect on the mental health, burden and quality of life of caregivers, with a greater impact among primary caregivers compared with the other living relatives.

"Unable to Feed My Hungry Child": Experiences of Mothers Caring for Children With Prader-Willi Syndrome

Mothers' experiences of caring for children with Prader-Willi Syndrome (PWS) is largely unknown. With no treatment for PWS, parents undertake (extra)ordinary care practices to keep children safe from overeating and self harm. Knowledge of these care practices could lead to effective interventions. Narrative inquiry was used to study everyday experience with Canadian mothers. Participants cared for a child 3 to 17 years old who had hyperphagia. Participants were interviewed 8 to 12 times each over the course of a year. Narrative accounts were co-composed through a collaborative process of analysis. Engaging with participants' everyday experiences amplified complex care needs for families and gaps in health and social care systems. Narrative threads focused on engaging in (extra)ordinary care practices, rigid care work to keep children healthy and safe, tension from others while enacting these care practices, and difficulty conforming to social expectations with childrearing and care work. Recommendations for practice and policy include (a) shifting from untenable care practices, (b) reconceptualizing care work, and (c) alternative care models.

A 14-year-old male patient with diagnosis of Prader-Willi syndrome in Ethiopia: a case report

BACKGROUND

Prader-Willi syndrome is a complex multisystem disorder due to the absent expression of paternally active genes in the Prader-Willi syndrome-critical region on chromosome 15 (15q11.2-q13). The main clinical features are hyperphagia (which frequently results in early-onset obesity), hypogonadism, developmental delays, typical behaviors (such as obsessive-compulsive tendencies, tantrums, perseveration, insistence on sameness, and rigidity), and distinctive facial features. In infants, the most prominent findings are hypotonia and feeding difficulties.

CASE PRESENTATION

This paper highlights a case of a 14 year old male patient of an Ethiopian ethnicity with diagnosis of Prader-Willi syndrome, which is first report in Ethiopia. He presented with progressive excessive weight gain, insatiable appetite, clinical and laboratory features of hypogonadism, ophthalmological refractory error, and facial features of Prader-Willi syndrome, which was further confirmed by genetic analysis. He is currently on lifestyle intervention, testosterone replacement, and treatment for vitamin D deficiency.

CONCLUSION

Prader-Willi syndrome should be considered in a child who presents with progressive weight gain and other typical clinical features such as cognitive impairment, excessive insatiable eating, or hypothalamic hypogonadism. Early lifestyle intervention may help to reduce excessive weight gain. To our knowledge, this is the first case reported in Ethiopia.

The Utilization of MS-MLPA as the First-Line Test for the Diagnosis of Prader-Willi Syndrome in Thai Patients

Prader-Willi syndrome (PWS) is a genetic disorder caused by the expression disruption of genes on the paternally inherited allele of chromosome 15q11.2-q13. Apart from clinical diagnostic criteria, PWS is confirmed by genetic testing. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) is one of the molecular techniques used to analyze this syndrome. This study aimed to evaluate the concordance of the test results of MS-MLPA with conventional techniques in the diagnosis of PWS in Thai patients. Forty leftover specimens from routine genetic testing (MS-PCR and FISH) were tested to obtain MS-MLPA results. By comparison, perfect concordance was shown between the result of MS-MLPA and those of conventional techniques. In conclusion, MS-MLPA is an accurate and cost-effective assay that can be used to confirm PWS diagnosis with explicit deletion of affected genes.

Management of Monogenic and Syndromic Obesity

Similar to the general population, lifestyle interventions focused on nutrition and physical activity form the foundation for treating obesity caused by rare genetic disorders. Additional therapies, including metreleptin and setmelanotide, that target defects within the leptin signaling pathway can effectively synergize with lifestyle efforts to treat monogenic disorders of leptin, leptin receptor, proopiomelanocortin (POMC), and proprotein convertase subtilisin/kexin type 1 (PCSK1) and syndromic conditions, such as the ciliopathies Bardet-Biedl and Alström syndromes, whose pathophysiological mechanisms also converge on the leptin pathway. Investigational treatments for Prader-Willi syndrome target specific defects caused by reduced expression of paternally derived genes within the chromosome 15q region.

Parental and familial factors related to participation in a home-based physical activity intervention in children with obesity or Prader-Willi syndrome

Background

Increasing physical activity (PA) participation is vital to promote the development of health behaviors in childhood. This study examined which parental and familial factors predicted completion of and compliance with a home-based family PA program in a cohort of families with a child with Prader-Willi syndrome (PWS; a rare disorder with obesity and developmental disability) or with obesity but with neurotypical development.

Methods

Participants (n = 105) were parents of children with PWS (n = 41) and parents of children with obesity but without PWS (n = 64). Parents completed a series of questionnaires documenting their demographic characteristics, self-efficacy, social support, and family environment (active-recreational orientation and cohesion). Relationships between these factors and intervention completion and compliance were evaluated using bivariate correlations and logistic regression (compliance) and multiple regression (completion) analyses with groups together and then separately if the child group was a significant predictor.

Results

None of the variables of interest (marital status, employment, employed hours per week, self-efficacy, social support, and family environment) were significant predictors of intervention completion. Intervention compliance was negatively associated with parents working part-time and working full-time and positively associated with family cohesion (Model R2 = 0.107, F(3,100) = 4.011, p = .010). Child group was not a factor.

Conclusions

Compliance with a 24-week family home-based PA intervention was related to fewer employment hours of the primary caregiver and family environment factors. Future interventions should consider how to reduce the intervention's burden in working parents along with strategies to foster family cohesion.

Analysis of Hyperphagia Questionnaire for Clinical Trials (HQ-CT) scores in typically developing individuals and those with Prader-Willi syndrome

The Hyperphagia Questionnaire for Clinical Trials (HQ-CT) is an observer-reported outcome measure that has been widely used in interventional studies to assess changes in hyperphagic behaviors in individuals with Prader-Willi syndrome (PWS). However, HQ-CT scores in the wider PWS population and the general population have not been reported. Here we report HQ-CT scores from more than 400 individuals with PWS and 600 typical individuals, aged 5-26. Overall, HQ-CT scores were significantly higher in those with PWS compared to typically developing individuals at all ages evaluated. In addition, while HQ-CT scores in the typically developing population decreased with age, scores increased with age in PWS. To further understand the variability of HQ-CT scores in the PWS population, semi-structured interviews were conducted with caregivers of a small subset of adults with PWS who had unexpectedly low HQ-CT scores. These caregivers reported that strict adherence to a food routine, food security measures and supervised food preparation reduced the frequency and intensity of hyperphagic behaviors measured by HQ-CT. Thus, hyperphagic behaviors are captured by the HQ-CT for most individuals with PWS, but for some individuals residing in settings with highly structured food routines, HQ-CT scores may not fully reflect the extent of PWS-associated hyperphagia.

Scoliosis and BMI in patients with Prader-Willi syndrome

Although scoliosis is commonly seen in patients with Prader-Willi syndrome, the patterns and extent of the deformity may change along their growth. Increased body weight is another issue in these patients, and its relationship with scoliosis is still controversial. The aim of this study was to evaluate scoliosis in patients with PWS, and its relationship with BMI. This was a retrospective cohort study in which a series of radiographic images and BMI from each patient were collected, and the data were rearranged following the age at which they were recorded. These patients were subsequently labeled as non-Scoliotic (<10°), Moderate (10° - 39°), and Severe (≥40°) according to their final Cobb angle, also as Normal (≤85%), Overweight (86%-95%), and Obese (≥95%) according to final BMI percentage. Thirty-four patients with age from 1 to 20 years old were recruited for this study, and the mean length of follow-up was 6.6 years. The prevalence of scoliosis was 71% (24 patients in Moderate, and 9 patients in Severe), and 65.6% were either overweight (11 patients) or obese (10 patients). The mean BMI percentage in non-scoliotic patients was 93.10 ± 13.84, which was significantly higher than that of the scoliotic groups ( P  = 0.0180). When looking at the longitudinal change, the non-Scoliotic group had high BMI since childhood, and obese patients had less spine deformity also from early childhood. In this study, we found that the prevalence of scoliosis in Taiwanese population with PWS was 71% without gender preference. Not every patient had a high BMI, and obese patients seemed to have significantly less chance to develop scoliosis. Level III.

The importance of gynecological examination in adolescent girls and adult women with Prader-Willi syndrome

Current published guidelines for routine care of women with Prader-Willi syndrome (PWS) do not include recommendations for gynecologic examinations. We describe our experience with gynecological examinations in women with PWS and offer recommendations for routine health care for these patients. Data were collected on all 41 PWS females ages ≥12 year, followed in our national Israeli multidisciplinary clinic between the years 2011 and 2022. Menstrual data and findings on external gynecological examination, including evaluation of the vulva and hymen were recorded at yearly visits. During the gynecological evaluation the topic of sexual education was discussed. Pelvic ultrasound, specifically for antral follicular count, was performed for those visiting the clinic during 2020-2022. Blood samples for luteinizing hormone (LH), follicular stimulating hormone (FSH), and estradiol were obtained routinely and DEXA scans for bone density were done when indicated. Of the 41 women, (median age at start of follow-up 17 years, range [12.3-39], BMI 30.4 kg/m2 [IQR 23.5-37.1]), 39 women agreed to external gynecological examination. Eleven women (27%) had spontaneous menses, with menarche at the age of 14 to as late as 31 years. The hymen was intact in all except one. Poor hygiene was observed in eight women, three women with vulvovaginitis, and five with irritated vulva related to poor hygiene. Gynecological ultrasound was performed in 27 women. In 22, endometrial thickness was less than 5 mm. The median antral follicular count (AFC) was 6 (<10th percentile for age). No correlation between AFC and menstruation or BMI was found. Mean FSH level was 5.7 ± 3.6 IU, LH was 2.29 ± 2.23, and estradiol was 128 ± 76 pmol/L. Data on DEXA measurements were available in 25 women aged 16-39. Median spine T score was -1.3 (range between 0.5 and -3.7), and hip T score was -1.2 (range between 0.8 and -3.3). A negative correlation was found between endometrial thickness and the presence of osteopenia or osteoporosis (r = -0.5, p = 0.013). Despite our recommendations, only eight of 14 women agreed to hormonal treatment or contraception. One woman who received treatment had a thromboembolic event. Routine health care for women with PWS should include gynecological examinations. The gynecological evaluation should include external genital examination, assessment of hygiene, obtaining a blood sample for hormone levels, and documenting a history of sexual experience or sexual abuse. Hormonal treatment or contraception should be offered when appropriate.

Current Approaches to Epigenetic Therapy

Epigenetic therapy is a promising tool for the treatment of a wide range of diseases. Several fundamental epigenetic approaches have been proposed. Firstly, the use of small molecules as epigenetic effectors, as the most developed pharmacological method, has contributed to the introduction of a number of drugs into clinical practice. Secondly, various innovative epigenetic approaches based on dCas9 and the use of small non-coding RNAs as therapeutic agents are also under extensive research. In this review, we present the current state of research in the field of epigenetic therapy, considering the prospects for its application and possible limitations.

Cell-specific secretory granule sorting mechanisms: the role of MAGEL2 and retromer in hypothalamic regulated secretion

Intracellular protein trafficking and sorting are extremely arduous in endocrine and neuroendocrine cells, which synthesize and secrete on-demand substantial quantities of proteins. To ensure that neuroendocrine secretion operates correctly, each step in the secretion pathways is tightly regulated and coordinated both spatially and temporally. At the trans-Golgi network (TGN), intrinsic structural features of proteins and several sorting mechanisms and distinct signals direct newly synthesized proteins into proper membrane vesicles that enter either constitutive or regulated secretion pathways. Furthermore, this anterograde transport is counterbalanced by retrograde transport, which not only maintains membrane homeostasis but also recycles various proteins that function in the sorting of secretory cargo, formation of transport intermediates, or retrieval of resident proteins of secretory organelles. The retromer complex recycles proteins from the endocytic pathway back to the plasma membrane or TGN and was recently identified as a critical player in regulated secretion in the hypothalamus. Furthermore, melanoma antigen protein L2 (MAGEL2) was discovered to act as a tissue-specific regulator of the retromer-dependent endosomal protein recycling pathway and, by doing so, ensures proper secretory granule formation and maturation. MAGEL2 is a mammalian-specific and maternally imprinted gene implicated in Prader-Willi and Schaaf-Yang neurodevelopmental syndromes. In this review, we will briefly discuss the current understanding of the regulated secretion pathway, encompassing anterograde and retrograde traffic. Although our understanding of the retrograde trafficking and sorting in regulated secretion is not yet complete, we will review recent insights into the molecular role of MAGEL2 in hypothalamic neuroendocrine secretion and how its dysregulation contributes to the symptoms of Prader-Willi and Schaaf-Yang patients. Given that the activation of many secreted proteins occurs after they enter secretory granules, modulation of the sorting efficiency in a tissue-specific manner may represent an evolutionary adaptation to environmental cues.

Intranasal oxytocin as a treatment for obesity: safety and efficacy

INTRODUCTION

Known for its effect on labor and lactation and on emotional and social functions, oxytocin has recently emerged as a key modulator of feeding behavior and indeed suggested as a potential treatment for obesity. The potential positive effect of oxytocin on both metabolic and psychological-behavioral complications of hypothalamic lesions makes it a promising tool in the management of these conditions.

AREAS COVERED

The aim of the present review article is to provide an overview of the mechanism of action and clinical experience of the use of oxytocin in different forms of obesity.

EXPERT OPINION

Current evidence suggests a potential role of oxytocin in the treatment of obesity with different causes. Several challenges remain: an improved understanding of the physiological regulation, mechanisms of action of oxytocin, and interplay with other endocrine axes is fundamental to clarify its role. Further clinical trials are needed to determine the safety and efficacy of oxytocin for the treatment of different forms of obesity. Understanding the mechanism(s) of action of oxytocin on body weight regulation might also improve our understanding of obesity and reveal possible new therapeutic targets - as well as promoting advances in other fields in which oxytocin might be used.

Generation of an induced pluripotent stem cell line, ZIPi021-A, from fibroblasts of a Prader-Willi syndrome patient with maternal uniparental disomy (mUPD)

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by loss of paternal expression of imprinted genes on chromosome 15q11-q13. We established a human induced pluripotent stem cell line (hiPSC), ZIPi021-A, from fibroblasts of a 4-year-old female PWS patient with the subtype of maternal uniparental disomy (mUPD). The generated hiPSC line was transgene-free, expressed pluripotency markers and showed the ability to differentiate into all three germ layers in vitro. The ZIPi021-A hiPSC line could be used as a cellular model for PWS in humans.

Hormonal Imbalances in Prader-Willi and Schaaf-Yang Syndromes Imply the Evolution of Specific Regulation of Hypothalamic Neuroendocrine Function in Mammals

The hypothalamus regulates fundamental aspects of physiological homeostasis and behavior, including stress response, reproduction, growth, sleep, and feeding, several of which are affected in patients with Prader-Willi (PWS) and Schaaf-Yang syndrome (SYS). PWS is caused by paternal deletion, maternal uniparental disomy, or imprinting defects that lead to loss of expression of a maternally imprinted region of chromosome 15 encompassing non-coding RNAs and five protein-coding genes; SYS patients have a mutation in one of them, MAGEL2. Throughout life, PWS and SYS patients suffer from musculoskeletal deficiencies, intellectual disabilities, and hormonal abnormalities, which lead to compulsive behaviors like hyperphagia and temper outbursts. Management of PWS and SYS is mostly symptomatic and cures for these debilitating disorders do not exist, highlighting a clear, unmet medical need. Research over several decades into the molecular and cellular roles of PWS genes has uncovered that several impinge on the neuroendocrine system. In this review, we will discuss the expression and molecular functions of PWS genes, connecting them with hormonal imbalances in patients and animal models. Besides the observed hormonal imbalances, we will describe the recent findings about how the loss of individual genes, particularly MAGEL2, affects the molecular mechanisms of hormone secretion. These results suggest that MAGEL2 evolved as a mammalian-specific regulator of hypothalamic neuroendocrine function.

The interaction between the nervous system and the stomatognathic system: from development to diseases

The crosstalk between the nerve and stomatognathic systems plays a more important role in organismal health than previously appreciated with the presence of emerging concept of the "brain-oral axis". A deeper understanding of the intricate interaction between the nervous system and the stomatognathic system is warranted, considering their significant developmental homology and anatomical proximity, and the more complex innervation of the jawbone compared to other skeletons. In this review, we provide an in-depth look at studies concerning neurodevelopment, craniofacial development, and congenital anomalies that occur when the two systems develop abnormally. It summarizes the cross-regulation between nerves and jawbones and the effects of various states of the jawbone on intrabony nerve distribution. Diseases closely related to both the nervous system and the stomatognathic system are divided into craniofacial diseases caused by neurological illnesses, and neurological diseases caused by an aberrant stomatognathic system. The two-way relationships between common diseases, such as periodontitis and neurodegenerative disorders, and depression and oral diseases were also discussed. This review provides valuable insights into novel strategies for neuro-skeletal tissue engineering and early prevention and treatment of orofacial and neurological diseases.

Metabolic and bariatric surgery for obesity in Prader Willi syndrome: systematic review and meta-analysis

Obesity is the leading cause of morbidity and mortality in patients with Prader-Willi Syndrome (PWS). Our objective was to compare changes in body mass index (BMI) after metabolic and bariatric surgery (MBS) for the treatment of obesity (BMI ≥35 kg/m2) in PWS. A systematic review of MBS in PWS was performed using PubMed, Embase, and Cochrane Central, identifying 254 citations. Sixty-seven patients from 22 articles met criteria for inclusion in the meta-analysis. Patients were organized into 3 groups: laparoscopic sleeve gastrectomy (LSG), gastric bypass (GB), and biliopancreatic diversion (BPD). No mortality within 1 year was reported in any of the 3 groups after a primary MBS operation. All groups experienced a significant decrease in BMI at 1 year with a mean reduction in BMI of 14.7 kg/m2 (P < .001). The LSG groups (n = 26) showed significant change from baseline in years 1, 2, and 3 (P value at year 3 = .002) but did not show significance in years 5, 7, and 10. The GB group (n = 10) showed a significant reduction in BMI of 12.1 kg/m2 in the first 2 years (P = .001). The BPD group (n = 28) had a significant reduction in BMI through 7 years with an average reduction of 10.7 kg/m2 (P = .02) at year 7. Individuals with PWS who underwent MBS had significant BMI reduction sustained in the LSG, GB, and BPD groups for 3, 2, and 7 years, respectively. No deaths within 1 year of these primary MBS operations were reported in this study or any other publication.

Register-based and genetic studies of Prader-Willi syndrome show a high frequency of gonadal tumors and a possible mechanism for tumorigenesis through imprinting relaxation

Prader-Willi syndrome (PWS) is a rare disease caused by a lack of expression of inherited imprinted genes in the paternally derived Prader-Willi critical region on chromosome 15q11.2-q13. It is characterized by poor feeding and hypotonia in infancy, intellectual disability, behavioral abnormalities, dysmorphic features, short stature, obesity, and hypogonadism. PWS is not a known cancer predisposition syndrome, but previous investigations regarding the prevalence of cancer in these patients suggest an increased risk of developing specific cancer types such as myeloid leukemia and testicular cancer. We present the results from a Swedish national population-based cohort study of 360 individuals with PWS and 18,000 matched comparisons. The overall frequency of cancer was not increased in our PWS cohort, but we found a high frequency of pediatric cancers. We also performed whole-genome sequencing of blood- and tumor-derived DNAs from a unilateral dysgerminoma in a 13-year-old girl with PWS who also developed bilateral ovarian sex cord tumors with annular tubules. In germline analysis, there were no additional findings apart from the 15q11.2-q13 deletion of the paternal allele, while a pathogenic activating KIT mutation was identified in the tumor. Additionally, methylation-specific multiplex ligation-dependent probe amplification revealed reduced methylation at the PWS locus in the dysgerminoma but not in the blood. In conclusion, our register-based study suggests an increased risk of cancer at a young age, especially testicular and ovarian tumors. We found no evidence of a general increase in cancer risk in patients with PWS. However, given our limited observational time, further studies with longer follow-up times are needed to clarify the lifetime cancer risk in PWS. We have also described the second case of locus-specific loss-of-imprinting in a germ cell tumor in PWS, suggesting a possible mechanism of carcinogenesis.

The Arduous Path to Drug Approval for the Management of Prader-Willi Syndrome: A Historical Perspective and Call to Action

Prader-Willi syndrome (PWS) is a neuroendocrine genetic disorder resulting from the loss of paternally expressed imprinted genes in chromosome 15q11-q13 [...].

Rapid-Onset Obesity With Hypothalamic Dysfunction, Hypoventilation, Autonomic Dysregulation, and Neuroendocrine Tumor (ROHHADNET) Syndrome: A Case Report

Here, we report the case of a rare and complex disorder, rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation, and neuroendocrine tumor (ROHHADNET) syndrome, in a three-year-old girl with no significant medical history. This is the first such case reported from the UAE. ROHHADNET is a rare disorder of respiratory control and autonomic nervous system regulation with endocrine abnormalities. It typically presents in children older than 18 months with rapid weight gain. This is a challenging diagnosis as there is no clear diagnostic test, and treatment is essentially supportive. This report describes a case of ROHHADNET syndrome in a previously well child who presented with rapid weight gain followed by ophthalmoplegia, dysphagia, electrolyte disturbance, and other comorbidities. The paper outlines in detail the clinical course, investigations, and management of ROHHADNET syndrome. Cerebrospinal fluid analysis revealed oligoclonal bands, which have been reported in only two other cases of ROHHADNET syndrome. Our goal in reporting this case is to increase awareness of this condition among clinicians to facilitate early diagnosis and timely management.

Genetics: A Starting Point for the Prevention and the Treatment of Obesity

Obesity is a common, serious, and costly disease. More than 1 billion people worldwide are obese-650 million adults, 340 million adolescents, and 39 million children. The WHO estimates that, by 2025, approximately 167 million people-adults and children-will become less healthy because they are overweight or obese. Obesity-related conditions include heart disease, stroke, type 2 diabetes, and certain types of cancer. These are among the leading causes of preventable, premature death. The estimated annual medical cost of obesity in the United States was nearly $173 billion in 2019 dollars. Obesity is considered the result of a complex interaction between genes and the environment. Both genes and the environment change in different populations. In fact, the prevalence changes as the result of eating habits, lifestyle, and expression of genes coding for factors involved in the regulation of body weight, food intake, and satiety. Expression of these genes involves different epigenetic processes, such as DNA methylation, histone modification, or non-coding micro-RNA synthesis, as well as variations in the gene sequence, which results in functional alterations. Evolutionary and non-evolutionary (i.e., genetic drift, migration, and founder's effect) factors have shaped the genetic predisposition or protection from obesity in modern human populations. Understanding and knowing the pathogenesis of obesity will lead to prevention and treatment strategies not only for obesity, but also for other related diseases.

Diazoxide Choline Extended-Release Tablet in People With Prader-Willi Syndrome: A Double-Blind, Placebo-Controlled Trial

CONTEXT

Prader-Willi syndrome (PWS) is a rare neurobehavioral-metabolic disease caused by the lack of paternally expressed genes in the chromosome 15q11-q13 region, characterized by hypotonia, neurocognitive problems, behavioral difficulties, endocrinopathies, and hyperphagia resulting in severe obesity if not controlled.

OBJECTIVE

The primary end point was change from baseline in hyperphagia using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT). Other end points included Global Impression Scores, and changes in body composition, behaviors, and hormones.

METHODS

In DESTINY PWS, a 13-week, randomized, double-blind, placebo-controlled, phase 3 trial, 127 participants with PWS aged 4 years and older with hyperphagia were randomly assigned 2:1 to diazoxide choline extended-release tablet (DCCR) or placebo.

RESULTS

DCCR did not significantly improve hyperphagia (HQ-CT least-square mean (LSmean) [SE] -5.94 [0.879] vs -4.27 [1.145]; P = .198), but did so in participants with severe hyperphagia (LSmean [SE] -9.67 [1.429] vs -4.26 [1.896]; P = .012). Two of 3 secondary end points were improved (Clinical Global Impression of Improvement [CGI-I]; P = .029; fat mass; P = .023). In an analysis of results generated pre-COVID, the primary (HQ-CT; P = .037) and secondary end points were all improved (CGI-I; P = .015; Caregiver Global Impression of Change; P = .031; fat mass; P = .003). In general, DCCR was well tolerated with 83.3% in the DCCR group experiencing a treatment-emergent adverse event and 73.8% in the placebo group (not significant).

CONCLUSION

DCCR did not significantly improve hyperphagia in the primary analysis but did in participants with severe baseline hyperphagia and in the pre-COVID analysis. DCCR treatment was associated with significant improvements in body composition and clinician-reported outcomes.

Intranasal Carbetocin Reduces Hyperphagia, Anxiousness, and Distress in Prader-Willi Syndrome: CARE-PWS Phase 3 Trial

CONTEXT

Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by endocrine and neuropsychiatric problems including hyperphagia, anxiousness, and distress. Intranasal carbetocin, an oxytocin analog, was investigated as a selective oxytocin replacement therapy.

OBJECTIVE

To evaluate safety and efficacy of intranasal carbetocin in PWS.

DESIGN

Randomized, double-blind, placebo-controlled phase 3 trial with long-term follow-up.

SETTING

Twenty-four ambulatory clinics at academic medical centers.

PARTICIPANTS

A total of 130 participants with PWS aged 7 to 18 years.

INTERVENTIONS

Participants were randomized to 9.6 mg/dose carbetocin, 3.2 mg/dose carbetocin, or placebo 3 times daily during an 8-week placebo-controlled period (PCP). During a subsequent 56-week long-term follow-up period, placebo participants were randomly assigned to 9.6 mg or 3.2 mg carbetocin, with carbetocin participants continuing at their previous dose.

MAIN OUTCOME MEASURES

Primary endpoints assessed change in hyperphagia (Hyperphagia Questionnaire for Clinical Trials [HQ-CT]) and obsessive-compulsive symptoms (Children's Yale-Brown Obsessive-Compulsive Scale [CY-BOCS]) during the PCP for 9.6 mg vs placebo, and the first secondary endpoints assessed these same outcomes for 3.2 mg vs placebo. Additional secondary endpoints included assessments of anxiousness and distress behaviors (PWS Anxiousness and Distress Behaviors Questionnaire [PADQ]) and clinical global impression of change (CGI-C).

RESULTS

Because of onset of the COVID-19 pandemic, enrollment was stopped prematurely. The primary endpoints showed numeric improvements in both HQ-CT and CY-BOCS which were not statistically significant; however, the 3.2-mg arm showed nominally significant improvements in HQ-CT, PADQ, and CGI-C scores vs placebo. Improvements were sustained in the long-term follow-up period. The most common adverse event during the PCP was mild to moderate flushing.

CONCLUSIONS

Carbetocin was well tolerated, and the 3.2-mg dose was associated with clinically meaningful improvements in hyperphagia and anxiousness and distress behaviors in participants with PWS.

CLINICAL TRIALS REGISTRATION NUMBER

NCT03649477.

A Personalized Approach to Determining the Caloric Needs of Children with Prader-Willi Syndrome Treated with Growth Hormone

Prader-Willi Syndrome (PWS) is the most frequent cause of genetic obesity. Early reports indicate that children with PWS require 20-40% fewer calories than healthy children to maintain adequate growth. Growth hormone treatment for children with PWS, approved in 2000, affects the body composition and probably affects energy requirements. This retrospective cross-sectional study analyzed the caloric intake in children with PWS aged from 6 months to 12 years old who underwent growth hormone treatment, comparing the patients' caloric intake calculated from parent-recorded dietary intake versus the recommended caloric intake for healthy children, taking into account the age, sex, height, weight, and physical activity. We analyzed the data from 25 patients (13 (52%) boys; mean age, 6.72 ± 2.81 y; median age at starting growth hormone treatment, 1.4 y (IQR: 0.78-2.29); 17 (68%) normal weight and 8 (32%) overweight or obese). The mean daily energy intake was 1208 ± 186 kcal/d, representing 96.83% ± 18.66 of the recommended caloric intake for healthy children. The caloric intake in children with PWS treated with growth hormone was very similar to that recommended for healthy children; thus, we should rethink the dietary recommendations for these children.

Current Treatments for Patients with Genetic Obesity

Obesity derives from impaired central control of body weight, implying interaction between environment and an individual genetic predisposition. Genetic obesities, including monogenic and syndromic obesities, are rare and complex neuro-endocrine pathologies where the genetic contribution is predominant. Severe and early-onset obesity with eating disorders associated with frequent comorbidities make these diseases challenging. Their current estimated prevalence of 5-10% in severely obese children is probably underestimated due to the limited access to genetic diagnosis. A central alteration of hypothalamic regulation of weight implies that the leptin-melanocortin pathway is responsible for the symptoms. The management of genetic obesity has so far been only based, above all, on lifestyle intervention, especially regarding nutrition and physical activity. New therapeutic options have emerged in the last years for these patients, raising great hope to manage their complex situation and improve quality of life. Implementation of genetic diagnosis in clinical practice is thus of paramount importance to allow individualized care. This review describes the current clinical management of genetic obesity and the evidence on which it is based. Some insights will also be provided into new therapies under evaluation.

Hypomethylation of the dopamine transporter (DAT) gene promoter is associated with hyperphagia-related behavior in Prader-Willi syndrome: a case-control study

Prader-Willi syndrome (PWS), a neurodevelopmental disorder based on the loss of paternally derived but maternally imprinted genes on chromosome 15q11-13, is typically associated with hyperphagia-related behavior leading to massive obesity. Recently, there has been increasing evidence for dysregulated expression patterns of genes outside the PWS locus that influence the behavioral phenotype and for alterations in the dopaminergic system associated with weight regulation in PWS. In this study, we investigated the epigenetic regulation of the promoter regions of the dopamine transporter (DAT) and dopamine receptor D2 (DRD2) genes and their association with hyperphagia-related behavior in PWS. Methylation of the DAT and DRD2 promoter regions was examined by DNA bisulfite sequencing in 32 individuals with PWS and compared with a control group matched for sex, age, and body mass index (BMI). Hyperphagia-related behavior was assessed using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT). Analysis by linear mixed models revealed a significant effect of factor group on mean DAT promoter methylation rate with decreased mean methylation in PWS (7.3 ± 0.4%) compared to controls (18.8 ± 0.6%), p < 0.001. In the PWS group, we further identified effects of HQ-CT score and BMI on DAT promoter methylation. Although also statistically significantly different (8.4 ± 0.2 in PWS, 10.5 ± 0.3 in controls, p < 0.001), DRD2 promoter methylation visually appeared to be evenly distributed between groups, raising concerns regarding a biological effect. Here, we provide evidence for altered epigenetic regulation of the DAT gene in PWS, which is associated with PWS-typical hyperphagia-related behaviors.

Associations between Oxidant/Antioxidant Status and Circulating Adipokines in Non-Obese Children with Prader-Willi Syndrome

Oxidative stress is implicated in the pathophysiology of Prader-Willi syndrome (PWS), but there are no data on these disorders in non-obese children with PWS. Therefore, the presented study examined total oxidant capacity (TOC), total antioxidant capacity (TAC), the oxidative stress index (OSI), and adipokine levels in 22 non-obese children with PWS during dietary intervention and growth hormone treatment compared with 25 non-obese healthy children. Serum concentrations of TOC, TAC, nesfatin-1, leptin, hepcidin, ferroportin, and ferritin were determined using immunoenzymatic methods. We found that TOC concentrations were higher by 50% (p = 0.006) in patients with PWS than in healthy children, but no significant differences in TAC concentrations were observed between these groups. The OSI was higher in children with PWS than in the controls (p = 0.002). We found positive associations between TOC values and the percentage of the Estimated Energy Requirement, body mass index (BMI) Z-score, percentage of fat mass, and leptin, nesfatin-1, and hepcidin concentrations in patients with PWS. A positive association was also found between the OSI and nesfatin-1 levels. These observations suggest that higher daily energy intake and weight gain may be accompanied by an increasing prooxidant state in these patients. Adipokines such as leptin, nesfatin-1, or hepcidin may also play a role in the prooxidant state in non-obese children with PWS.

Computer-aided facial analysis as a tool to identify patients with Silver-Russell syndrome and Prader-Willi syndrome

Genetic syndromes often show facial features that provide clues for the diagnosis. However, memorizing these features is a challenging task for clinicians. In the last years, the app Face2Gene proved to be a helpful support for the diagnosis of genetic diseases by analyzing features detected in one or more facial images of affected individuals. Our aim was to evaluate the performance of the app in patients with Silver-Russell syndrome (SRS) and Prader-Willi syndrome (PWS). We enrolled 23 pediatric patients with clinically or genetically diagnosed SRS and 29 pediatric patients with genetically confirmed PWS. One frontal photo of each patient was acquired. Top 1, top 5, and top 10 sensitivities were analyzed. Correlation with the specific genetic diagnosis was investigated. When available, photos of the same patient at different ages were compared. In the SRS group, Face2Gene showed top 1, top 5, and top 10 sensitivities of 39%, 65%, and 91%, respectively. In 41% of patients with genetically confirmed SRS, SRS was the first syndrome suggested, while in clinically diagnosed patients, SRS was suggested as top 1 in 33% of cases (p = 0.74). Face2Gene performed better in younger patients with SRS: in all patients in whom a photo taken at a younger age than the age of enrollment was available, SRS was suggested as top 1, albeit with variable degree of probability. In the PWS group, the top 1, top 5, and top 10 sensitivities were 76%, 97%, and 100%, respectively. PWS was suggested as top 1 in 83% of patients genetically diagnosed with paternal deletion of chromosome 15q11-13 and in 60% of patients presenting with maternal uniparental disomy of chromosome 15 (p = 0.17). The performance was uniform throughout the investigated age range (1-15 years).

CONCLUSION

In addition to a thorough medical history and detailed clinical examination, the Face2Gene app can be a useful tool to support clinicians in identifying children with a potential diagnosis of SRS or PWS.

WHAT IS KNOWN

• Several genetic syndromes present typical facial features that may provide clues for the diagnosis. • Memorizing all syndromic facial characteristics is a challenging task for clinicians.

WHAT IS NEW

• Face2Gene may represent a useful support for pediatricians for the diagnosis of genetic syndromes. • Face2Gene app can be a useful tool to integrate in the diagnostic path of patients with SRS and PWS.

Prader–Willi Syndrome and Weight Gain Control: From Prevention to Surgery—A Narrative Review

Severe obesity remains one of the most important symptoms of Prader–Willi Syndrome (PWS), and controlling weight represents a crucial point in the therapeutical approach to the syndrome. We present an overview of different progressive patterns of growth that involve controlling weight in PWS. Mechanisms involved in the development of obesity and in preventive and therapeutic strategies to control weight gain are discussed. Early diagnosis, a controlled diet regimen, regular physical activity, follow-up by multidisciplinary teams, and hormonal treatment improved the management of excessive weight gain. In selected cases, a surgical approach can be also considered. Controlling weight in PWS remains a challenge for pediatricians. The importance of consulting different healthcare specialists, starting from the neonatal and pediatric age, is also considered as a crucial approach to controlling weight, as well as to limiting and preventing the onset of obesity and its complications.

Oxytocin receptors in the Magel2 mouse model of autism: Specific region, age, sex and oxytocin treatment effects

The neurohormone oxytocin (OXT) has been implicated in the regulation of social behavior and is intensively investigated as a potential therapeutic treatment in neurodevelopmental disorders characterized by social deficits. In the Magel2-knockout (KO) mouse, a model of Schaaf-Yang Syndrome, an early postnatal administration of OXT rescued autistic-like behavior and cognition at adulthood, making this model relevant for understanding the actions of OXT in (re)programming postnatal brain development. The oxytocin receptor (OXTR), the main brain target of OXT, was dysregulated in the hippocampus of Magel2-KO adult males, and normalized upon OXT treatment at birth. Here we have analyzed male and female Magel2-KO brains at postnatal day 8 (P8) and at postnatal day 90 (P90), investigating age, genotype and OXT treatment effects on OXTR levels in several regions of the brain. We found that, at P8, male and female Magel2-KOs displayed a widespread, substantial, down-regulation of OXTR levels compared to wild type (WT) animals. Most intriguingly, the postnatal OXT treatment did not affect Magel2-KO OXTR levels at P8 and, consistently, did not rescue the ultrasonic vocalization deficits observed at this age. On the contrary, the postnatal OXT treatment reduced OXTR levels at P90 in male Magel2-KO in a region-specific way, restoring normal OXTR levels in regions where the Magel2-KO OXTR was upregulated (central amygdala, hippocampus and piriform cortex). Interestingly, Magel2-KO females, previously shown to lack the social deficits observed in Magel2-KO males, were characterized by a different trend in receptor expression compared to males; as a result, the dimorphic expression of OXTR observed in WT animals, with higher OXTR expression observed in females, was abolished in Magel2-KO mice. In conclusion, our data indicate that in Magel2-KO mice, OXTRs undergo region-specific modifications related to age, sex and postnatal OXT treatment. These results are instrumental to design precisely-timed OXT-based therapeutic strategies that, by acting at specific brain regions, could modify the outcome of social deficits in Schaaf-Yang Syndrome patients.

Factors Associated With Response to Growth Hormone in Pediatric Growth Disorders: Results of a 5-year Registry Analysis

Context

Growth hormone (GH) therapy can increase linear growth in patients with growth hormone deficiency (GHD), Turner syndrome (TS), Noonan syndrome (NS), and Prader-Willi syndrome (PWS), although outcomes vary by disease state.

Objective

To assess growth and identify factors associated with growth response with long-term GH therapy.

Methods

Data from pediatric patients with GHD, TS, NS, and PWS obtained at GH treatment initiation (baseline) and annually for 5 years in the ANSWER Program and NordiNet® IOS were analyzed retrospectively. Height standard deviation score (HSDS) was assessed over time, and multivariate analyses determined variables with significant positive effects on growth outcomes in each patient cohort.

Results

Data from patients with GHD (n = 12 683), TS (n = 1307), NS (n = 203), and PWS (n = 102) were analyzed. HSDS increased over time during GH treatment in all cohorts. Factors with significant positive effects on ΔHSDS were younger age at GH initiation and lower HSDS at baseline (all cohorts) and higher GH dose (GHD and TS only); sex had no effect in any cohort. The modeling analysis showed that ΔHSDS was greatest in year 1 and attenuated over consecutive years through year 5. Estimated least-squares mean ΔHSDS values at year 5 by cohort were 1.702 (females) and 1.586 (males) in GHD, 1.033 in TS, 1.153 in NS, and 1.392 in PWS.

Conclusion

Long-term GH therapy results in large increases in HSDS in patients with GHD, TS, NS, and PWS. Greater gains in HSDS can be obtained with higher GH doses and earlier initiation of treatment.