GrowthHormone Research Society workshop summary: consensus guidelines for recombinant human growth hormone therapy in Prader-Willi syndrome

Congenital Central Hypoventilation Syndrome and Disorders of Control of Ventilation

Congenital disorders of ventilatory control typically manifest as central apneas, periodic breathing, and hypoventilation in the neonatal period, but some may present at a later age. Obstructive apneas may be the initial presentation, and some may have associated autonomic nervous system dysfunction. Individuals with these disorders can have absent or impaired ventilatory and arousal responses to hypoxemia and hypercapnia. This article discusses the presentation, pathophysiology, evaluation, and management of congenital central hypoventilation syndrome, rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome, Prader-Willi syndrome, and myelomeningocele.

Childhood growth hormone treatment: challenges, opportunities, and considerations

With long standing demand and popularity, growth hormone treatments continue to be a topic of interest for paediatric endocrinologists and general paediatricians due to ongoing issues regarding their long-term effects, the safety of childhood treatment, and the introduction of long-acting growth hormone preparations in the past decade. Moreover, uncertainty regarding how to approach individual patients and their treatment indications remains, particularly concerning tailored treatment goals and objectives; this uncertainty is further complicated by the multitude of approved indications that surpass substitution therapy. The paediatric endocrinologist thus grapples with pertinent questions, such as what defines reasonable treatment goals for each individual given their indications, and when (and how) to initiate the necessary discussions about risks and benefits with patients and their families. The aim of this Review is to offer advanced physiological concepts of growth hormone function, map out approved paediatric indications for treatment along with evidence on their effects and safety, highlight controversies and complexities surrounding childhood growth hormone treatment, and discuss the potential of long-acting growth hormone and future directions in the realm of childhood growth hormone treatment.

Long-term effect of growth hormone on sleep-disordered breathing in Malaysian children with Prader-Willi syndrome: a retrospective study

STUDY OBJECTIVES

The effect of recombinant human growth hormone (rhGH) on sleep-disordered breathing (SDB) in Malaysian children with Prader-Willi syndrome (PWS) is under-investigated. We determined (1) the short- and long-term effects of rhGH and (2) factors associated with worsening SDB in children with PWS receiving rhGH.

METHODS

This retrospective study included children with PWS (with and without rhGH) who had undergone at least 1 polysomnography. Outcomes measured were the presence of SDB before and after starting rhGH and the progress of SDB with and without rhGH. Serial insulin-like growth factor 1 (IGF-1) measurements were recorded.

RESULTS

One-hundred and thirteen polysomnograms were analyzed. The majority (92.3%) of initial polysomnograms showed SDB, with a median (interquartile range) apnea-hypopnea index of 5.0 (2.6, 16.3) events/h. The age for receiving rhGH was a median (IQR) of 1.9 (0.7, 3.4) years. One-third (36.8%) had worsening SDB after initiating rhGH, which was associated with higher IGF-1 levels post-rhGH (P = .007). After a median of 5 years of rhGH, 73.6% maintained or reduced their positive airway pressure settings. Without rhGH, 80% had increased their positive airway pressure settings. Worsening SDB while on rhGH was associated with higher body mass index, lower rhGH dose, higher IGF-1 levels, and non-15q deletion.

CONCLUSIONS

The majority of Malaysian children with PWS had SDB. At initiation of rhGH, one-third of patients had worsening SDB, associated with increased IGF-1 levels. Stabilization of SDB was more frequently seen in those receiving long-term rhGH. Worsening SDB while on rhGH was associated with a higher body mass index, receiving a lower dose of rhGH, higher IGF-1 levels, and non-15q deletion.

CITATION

Tan YT, Azanan MS, Hng SY, et al. Long-term effect of growth hormone on sleep-disordered breathing in Malaysian children with Prader-Willi syndrome: a retrospective study. J Clin Sleep Med. 2024;20(8):1291-1299.

Outcomes of growth hormone treatment in children with Prader-Willi syndrome over a 30-year period: a single tertiary center experience

OBJECTIVES

Clinical benefits of growth hormone (GH) in Prader-Willi syndrome (PWS) are proven and scoliosis is a known association of both PWS and GH therapy. The aims of this study were to assess GH prescribing practices and growth outcomes over time, the prevalence and predictors of scoliosis in GH-treated PWS children, and the near-final height of GH-treated PWS patients.

DESIGN AND METHODS

This is a retrospective, descriptive study evaluating data from all clinic visits of patients aged 0-18 years with PWS, seen through the Children's Hospital at Westmead between March 1992 and May 2022 (n=75).

RESULTS

A total of 64 patients were treated with GH (visits = 1,414). In the recent decade, the diagnosis of PWS and GH commencement were made significantly earlier in life. The prevalence of scoliosis was 41 %, in which age was the only significant predictor for scoliosis (odds ratio 1.19: 95 % CI [1.08-1.31; p=0.001]) adjusted for other predictors. In patients with data available at the age 16 years (23/28 treated with GH), those who were GH treated had significantly higher height SDS vs. nontreated group (SDS -0.67 vs. -2.58; p=0.0001) and lower BMI SDS (1.18 vs. 2.37; p<0.001).

CONCLUSIONS

Significant improvements in growth and body composition were seen in the GH-treated group vs. non-treated group of children with PWS. There were no significant modifiable clinical predictors of scoliosis in children with PWS, but our findings confirm the high prevalence of scoliosis in GH-treated children with PWS reinforcing the need for close surveillance.

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.

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.

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.

Endocrine features of Prader-Willi syndrome: a narrative review focusing on genotype-phenotype correlation

Prader-Willi syndrome (PWS) is a complex genetic disorder caused by three different types of molecular genetic abnormalities. The most common defect is a deletion on the paternal 15q11-q13 chromosome, which is seen in about 60% of individuals. The next most common abnormality is maternal disomy 15, found in around 35% of cases, and a defect in the imprinting center that controls the activity of certain genes on chromosome 15, seen in 1-3% of cases. Individuals with PWS typically experience issues with the hypothalamic-pituitary axis, leading to excessive hunger (hyperphagia), severe obesity, various endocrine disorders, and intellectual disability. Differences in physical and behavioral characteristics between patients with PWS due to deletion versus those with maternal disomy are discussed in literature. Patients with maternal disomy tend to have more frequent neurodevelopmental problems, such as autistic traits and behavioral issues, and generally have higher IQ levels compared to those with deletion of the critical PWS region. This has led us to review the pertinent literature to investigate the possibility of establishing connections between the genetic abnormalities and the endocrine disorders experienced by PWS patients, in order to develop more targeted diagnostic and treatment protocols. In this review, we will review the current state of clinical studies focusing on endocrine disorders in individuals with PWS patients, with a specific focus on the various genetic causes. We will look at topics such as neonatal anthropometry, thyroid issues, adrenal problems, hypogonadism, bone metabolism abnormalities, metabolic syndrome resulting from severe obesity caused by hyperphagia, deficiencies in the GH/IGF-1 axis, and the corresponding responses to treatment.

Improving care for rare genetic neurodevelopmental disorders: A systematic review and critical appraisal of clinical practice guidelines using AGREE II

PURPOSE

Rare genetic neurodevelopmental disorders associated with intellectual disability require lifelong multidisciplinary care. Clinical practice guidelines may support healthcare professionals in their daily practice, but guideline development for rare conditions can be challenging. In this systematic review, the characteristics and methodological quality of internationally published recommendations for this population are described to provide an overview of current guidelines and inform future efforts of European Reference Network ITHACA (Intellectual disability, TeleHealth, Autism, and Congenital Anomalies).

METHODS

MEDLINE, Embase, and Orphanet were systematically searched to identify guidelines for conditions classified as "rare genetic intellectual disability" (ORPHA:183757). Methodological quality was assessed using the Appraisal of Guidelines, Research, and Evaluation II tool.

RESULTS

Seventy internationally published guidelines, addressing the diagnosis and/or management of 28 conditions, were included. The methodological rigor of development was highly variable with limited reporting of literature searches and consensus methods. Stakeholder involvement and editorial independence varied as well. Implementation was rarely addressed.

CONCLUSION

Comprehensive, high-quality guidelines are lacking for many rare genetic neurodevelopmental disorders. Use and transparent reporting of sound development methodologies, active involvement of affected individuals and families, robust conflict of interest procedures, and attention to implementation are vital for enhancing the impact of clinical practice recommendations.

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.

A case of mosaic deletion of paternally-inherited PLAGL1 and two cases of upd(6)mat add to evidence for PLAGL1 under-expression as a cause of growth restriction

PLAGL1 is one of a group of imprinted genes, whose altered expression causes imprinting disorders impacting growth, development, metabolism, and behavior. PLAGL1 over-expression causes transient neonatal diabetes mellitus (TNDM type 1) and, based on murine models, under-expression would be expected to cause growth restriction. However, only some reported individuals with upd(6)mat have growth restriction, giving rise to uncertainty about the role of PLAGL1 in human growth. Here we report three individuals investigated for growth restriction, two with upd(6)mat and one with a mosaic deletion of the paternally-inherited allele of PLAGL1. These cases add to evidence of its involvement in pre- and early post-natal human growth.

Effect of non-pharmacological intervention on the nutritional status of patients with Prader Willi Syndrome

INTRODUCTION

Obesity is highly prevalent in patients with Prader-Willi syndrome (PWS), particularly among adults. This condition, which can be morbid in many cases, is multifactorial and has a complex management. The purpose of our study was to describe the feasibility of achieving a better nutritional status, including normal weight in individuals diagnosed with PWS, through specific nutritional interventions within the framework of a transdisciplinary treatment and without resorting to pharmacological treatments or growth hormone (GH).

METHODOLOGY

This observational study included patients with confirmed genetic diagnosis of PWS, receiving transdisciplinary treatment in a specialized rare diseases institution. Patients under treatment with GH and those under pharmacological treatment with nutritional objectives were excluded from the study. All patients attended our institution regularly on a weekly or fortnightly basis. Anthropometric records, including weight, height, and body mass index (BMI) were evaluated in each visit from treatment onset until the last check-up.

RESULTS

We included 24 patients with confirmed genetic diagnosis of PWS. At baseline, 9 patients (38 %) had obesity grade III, 1 (4 %) of obesity grade II, 10 (42 %) of obesity grade I, 2 (8 %) of overweight, and 2 patients (8 %) with normal baseline weight. After a median duration of 52 months (interquartile range 23-116 months) of transdisciplinary nutritional treatment, we identified a significant reduction in BMI (baseline 40.2 ± 15.7 kg/m2 vs. follow-up 28.3 ± 6.7 kg/m2, p < 0.0001), without significant differences regarding height (baseline 1.45 ± 0.1 m vs. follow-up 1.48 ± 0.1 m, p = 0.09).

CONCLUSION

In this study, we demonstrated that nutritional nonpharmacologic interventions immersed in a transdisciplinary treatment enabled a consistent and sustainable improvement in BMI and nutritional status among patients with PWS.

Evaluating the effect of recombinant human growth hormone treatment on sleep-related breathing disorders in toddlers with Prader-Willi syndrome: a one-year retrospective cohort study

BACKGROUND

Recombinant human growth hormone (rhGH) therapy is beneficial for children with Prader-Willi syndrome (PWS) in improving short stature and metabolism, but the effect of early rhGH treatment on respiratory and sleep parameters for PWS children under three years old remains elusive. Thus, this study aimed to investigate the impact of rhGH treatment on sleep-related breathing disorders (SRBDs) for toddlers with PWS.

METHODS

A total of 17 age-matched PWS patients receiving rhGH treatment (rhGH group) and 17 control individuals not receiving rhGH treatment (non-rhGH group) were recruited for this study between October 2018 and January 2023. Data related to polysomnography-polygraphy (PSG) and serum levels of insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) were collected.

RESULTS

The mean age in the rhGH group was 20.76 ± 9.22 months, which was comparable to that of the non-rhGH group (25.23 ± 13.81 months). The demographic and anthropometric parameters were similar across the two groups after 52 weeks of treatment. Administration of rhGH to toddlers did not exert adverse effects on the obstructive apnea-hypopnea index (OAHI), central apnea index (CAI), oxygen desaturation index (ODI), mean percutaneous oxygen saturation (SpO2), lowest SpO2, duration when SpO2 is lower than 90%, or proportion of the patients with SpO2 lower than 90%. Furthermore, the increased IGF-1 z-score and IGFBP-3 level did not worsen SRBDs.

CONCLUSION

Treatment with rhGH for 52 weeks on young toddlers with PWS showed no deleterious effects on SRBDs. This shed more light on the importance of initiating rhGH therapy early in PWS patients.

Hypoventilation in patients with Prader-Willi syndrome across the pediatric age

OBJECTIVES

Few data on alveolar hypoventilation in Prader-Willi syndrome (PWS) are available and the respiratory follow-up of these patients is not standardized. The objectives of this study were to evaluate the prevalence of alveolar hypoventilation in children with PWS and identify potential risk factors.

STUDY DESIGN

This retrospective study included children with PWS recorded by polysomnography (PSG) with transcutaneous carbon dioxide pressure (PtcCO2) or end-tidal CO2 (ETCO2) measurements, between 2007 and 2021, in a tertiary hospital center. The primary outcome was the presence of alveolar hypoventilation defined as partial pressure of carbon dioxide (pCO2) ≥ 50 mmHg during ≥2% of total sleep time (TST) or more than five consecutive minutes.

RESULTS

Among the 57 included children (38 boys, median age 4.8 years, range 0.1-15.6, 60% treated with growth hormone [GH], 37% obese), 19 (33%) had moderate-to-severe obstructive sleep apnea syndrome (defined as obstructive apnea-hypopnea index ≥5/h) and 20 (35%) had hypoventilation. The median (range) pCO2 max was 49 mmHg (38-69). Among the children with hypoventilation, 25% were asymptomatic. Median age and GH treatment were significantly higher in children with hypoventilation compared to those without. There was no significant difference in terms of sex, BMI, obstructive or central apnea-hypopnea index between both groups.

CONCLUSION

The frequency of alveolar hypoventilation in children and adolescents with PWS is of concern and may increase with age and GH treatment. A regular screening by oximetry-capnography appears to be indicated whatever the sex, BMI, and rate of obstructive or central apneas.

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.

Prevalence of Sleep-Disordered Breathing in Prader-Willi Syndrome

Introduction

Sleep-disordered breathing (SDB) is common in patients with Prader-Willi Syndrome (PWS). However, the prevalence of SDB varies widely between studies. Early identification of SDB and factors contributing to its incidence is essential, particularly when considering growth hormone (GH) therapy.

Objectives

The aims of the study were to describe the prevalence and phenotypes of sleep-disordered breathing (SDB) in patients with Prader-Willi syndrome (PWS) and to determine the effects of age, gender, symptoms, GH therapy and body mass index on SDB severity.

Methods

This study was a retrospective chart review of all patients with genetically confirmed Prader-Willi syndrome who underwent diagnostic overnight polysomnography (PSG) in the sleep laboratory at Sidra Medicine. Clinical and PSG data of enrolled patients were collected.

Results

We identified 20 patients (nine males, eleven females) with PWS who had overnight sleep polysomnography (PSG) at a median age (IQR) of 5.83 (2.7-12) years. The median apnea-hypopnea index (AHI) was 8.55 (IQR 5.8-16.9) events/hour. The median REM-AHI was 27.8 (IQR 15-50.6) events/hour. The median obstructive apnea-hypopnea index (OAHI) was 7.29 (IQR 1.8-13.5) events/hour. The median central apnea-hypopnea index (CAHI) was 1.77 (IQR 0.6-4.1) events/hour. Nineteen patients (95%) demonstrated SDB by polysomnography (PSG) based on AHI ≥1.5 events/hour. Nine patients (45%) were diagnosed with obstructive sleep apnea (OSA). Three patients (15%) were diagnosed with central sleep apnea (CSA). Seven patients (35%) were diagnosed with mixed sleep apnea. No correlations were observed between AHI and age, gender, BMI, symptoms, or GH therapy. However, REM-AHI was significantly correlated with BMI (P=0.031).

Conclusion

This study shows a high prevalence of SDB among our patients with PWS. Obstructive sleep apnea was the predominant phenotype. BMI was the only predictor for high REM-AHI. Further studies of large cohorts are warranted to define SDB in PWS and design the appropriate treatment.

Longitudinal changes in acylated versus unacylated ghrelin levels may be involved in the underlying mechanisms of the switch in nutritional phases in Prader-Willi syndrome

INTRODUCTION

Prader-Willi syndrome (PWS) is characterized by a switch from failure to thrive to excessive weight gain and hyperphagia in early childhood. An elevated, more unfavorable ratio between acylated and unacylated ghrelin (AG/UAG ratio) might play a role in the underlying mechanisms of this switch. We aimed to assess the evolution of the appetite regulating hormones acylated ghrelin (AG) and unacylated ghrelin (UAG) and the AG/UAG ratio and their association with the change in eating behavior in children with PWS, compared to healthy age-matched controls.

METHODS

Longitudinal study in 134 children with PWS and 157 healthy controls, from The Netherlands, France and Belgium. Levels of AG and UAG and the AG/UAG ratio were measured and nutritional phases as reported for PWS were scored.

RESULTS

The AG/UAG ratio was in the first years of life lower in PWS than in controls and started to increase from the age of 3 years, resulting in a high-normal AG/UAG ratio compared to controls. The AG levels remained stable during the different nutritional phases (p=0.114), while the UAG levels decreased from 290 pg/ml in phase 1a to 137 pg/ml in phase 2b (p<0.001). The AG/UAG ratio increased significantly from 0.81 in phase 2a to 1.24 in phase 2b (p= 0.012).

CONCLUSIONS

The change from failure to thrive to excessive weight gain and hyperphagia in infants and children with PWS coincides with an increase in AG/UAG ratio. The increase in AG/UAG ratio occurred during phase 2a, thus before the onset of hyperphagia.

First results of the growth disorders related twinning programme Partners4Growth implemented at the tertiary university pediatric endocrinology clinics in Bulgaria

OBJECTIVES

Early diagnosis of childhood growth disorders, their timely and proper treatment are important for better outcomes.The aim of the present study was to assess the results of the first 18 months of the growth disorders related twinning programme "Partners4Growth" implemented at all tertiary university pediatric endocrinology clinics in Bulgaria.

METHODS

In 2019, Partners4Growth started operation at 7 centres (4 experienced and 3 twin centres) with the main aim of aligning their practices in the shortest possible time. Education of twin centres' personnel was organized, equipment and methods for growth evaluation and follow-up were standardized. The approach was tested initially at one centre. At baseline and at the 18th month a questionnaire concerning diagnosis and management of recombinant human growth hormone (rhGH) requiring disorders was applied.

RESULTS

A total of 104 new patients were diagnosed compared to 30 in the previous year. Of those, 91 started rhGH treatment - 65 (64 %) GH deficient, 12 (12 %) Turner syndrome, 7 (7 %) Prader-Willi syndrome patients, and 7 (7 %) born small for gestational age without postnatal catch-up, representing 35.8 % of all currently rhGH treated Bulgarian children. A better geographical coverage and more advanced diagnostic and management practices were achieved.

CONCLUSIONS

Partners4Growth facilitated the alignment of the tertiary pediatric endocrinology centres competences thus leading to an improved diagnosis and treatment of growth disorders as well as better patients' access. For its short existence, the Programme increased significantly the number of new patients in the difficult times of COVID-19 pandemic thus justifying its continuation.

Analysis of the Diet Quality and Nutritional State of Children, Youth, and Young Adults with Prader-Willi Syndrome: A Polish Multiple Case Study

Given the lack of data on dietary quality in young individuals with Prader-Willi syndrome (PWS) in Poland, a multiple case study was conducted in which anthropometric measurements and 7-day dietary records were collected from 20 subjects with PWS. The study group consisted of 8 females and 12 males with a mean age of 14.8 years and a mean BMI of 21.6. Based on BMI analysis, five subjects were overweight, including two subjects who were obese. The study showed that 35% of the subjects had energy intakes above the recommended levels. Protein deficiency was found in one subject in the analyzed diets. However, fat intake was excessive in four subjects, and the majority exceeded the recommended intake of saturated fatty acids. Vitamin E and B12 deficiencies were found in 40% and 85% of the subjects, respectively. All subjects had inadequate intakes of vitamin D and iodine, while the majority had deficiencies in sodium and copper intakes. Calcium intake was deficient in 35% of the subjects. However, most subjects met recommendations for the intakes of other minerals, vitamins, and fiber. These findings confirm the suboptimal dietary patterns of Polish individuals with PWS, with deficits observed in the intake of certain vitamins and minerals.

The Impact of Growth Hormone Therapy on Sleep-Related Health Outcomes in Children with Prader-Willi Syndrome: A Review and Clinical Analysis

This literature review of growth hormone (GH) therapy and sleep-related health outcomes in children diagnosed with Prader-Willi syndrome (PWS) assembles evidence for the consequences of sleep deprivation and poor sleep quality: difficulty concentrating and learning at school, behavioral problems, diminished quality of life, and growth impairment. Sleep-disordered breathing (SDB) is another factor that impacts a child's well-being. We searched the electronic databases Medline PubMed Advanced Search Builder, Scopus, and Web of Science using MeSH terms and text words to retrieve articles on GH deficiency, recombinant human growth hormone (rhGH) therapy, sleep quality, SDB, and PWS in children. The censor date was April 2023. The initial search yielded 351 articles, 23 of which were analyzed for this review. The study findings suggest that while GH may have a role in regulating sleep, the relationship between GH treatment and sleep in patients with PWS is complex and influenced by GH dosage, patient age, and type and severity of respiratory disorders, among other factors. GH therapy can improve lung function, linear growth, and body composition in children with PWS; however, it can also trigger or worsen obstructive sleep apnea or hypoventilation in some. Long-term GH therapy may contribute to adenotonsillar hypertrophy and exacerbate sleep apnea in children with PWS. Finally, GH therapy can improve sleep quality in some patients but it can also cause or worsen SDB in others, leading to diminished sleep quality and overall quality of life. The current evidence suggests that the initial risk of worsening SDB may improve with long-term therapy. In conclusion, rhGH is the standard for managing patients with PWS. Nonetheless, its impact on respiratory function during sleep needs to be thoroughly evaluated. Polysomnography is advisable to assess the need for adenotonsillectomy before initiating rhGH therapy. Close monitoring of sleep disorders in patients with PWS receiving GH therapy is essential to ensure effective and safe treatment.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): a collaborative review of the current understanding

PURPOSE

To provide an overview of the discovery, presentation, and management of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD). To discuss a search for causative etiology spanning multiple disciplines and continents.

METHODS

The literature (1965-2022) on the diagnosis, management, pathophysiology, and potential etiology of ROHHAD was methodically reviewed. The experience of several academic centers with expertise in ROHHAD is presented, along with a detailed discussion of scientific discovery in the search for a cause.

RESULTS

ROHHAD is an ultra-rare syndrome with fewer than 200 known cases. Although variations occur, the acronym ROHHAD is intended to alert physicians to the usual sequence or unfolding of the phenotypic presentation, including the full phenotype. Nearly 60 years after its first description, more is known about the pathophysiology of ROHHAD, but the etiology remains enigmatic. The search for a genetic mutation common to patients with ROHHAD has not, to date, demonstrated a disease-defining gene. Similarly, a search for the autoimmune basis of ROHHAD has not resulted in a definitive answer. This review summarizes current knowledge and potential future directions.

CONCLUSION

ROHHAD is a poorly understood, complex, and potentially devastating disorder. The search for its cause intertwines with the search for causes of obesity and autonomic dysregulation. The care for the patient with ROHHAD necessitates collaborative international efforts to advance our knowledge and, thereby, treatment, to decrease the disease burden and eventually to stop, and/or reverse the unfolding of the phenotype.

Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors

Sleep is a fundamental biological necessity, the lack of which has severe repercussions on the mental and physical well-being in individuals of all ages. The phrase "sleep-disordered breathing (SDB)" indicates a wide array of conditions characterized by snoring and/or respiratory distress due to increased upper airway resistance and pharyngeal collapsibility; these range from primary snoring to obstructive sleep apnea (OSA) and occur in all age groups. In the general pediatric population, the prevalence of OSA varies between 2% and 5%, but in some particular clinical conditions, it can be much higher. While adenotonsillar hypertrophy ("classic phenotype") is the main cause of OSA in preschool age (3-5 years), obesity ("adult phenotype") is the most common cause in adolescence. There is also a "congenital-structural" phenotype that is characterized by a high prevalence of OSA, appearing from the earliest ages of life, supported by morpho-structural abnormalities or craniofacial changes and associated with genetic syndromes such as Pierre Robin syndrome, Prader-Willi, achondroplasia, and Down syndrome. Neuromuscular disorders and lysosomal storage disorders are also frequently accompanied by a high prevalence of OSA in all life ages. Early recognition and proper treatment are crucial to avoid major neuro-cognitive, cardiovascular, and metabolic morbidities.

Long-term effects of GH therapy in adult patients with Prader-Willi syndrome: a longitudinal study

Introduction

Prader-Willi syndrome (PWS) is a complex disorder resulting from the failure of expression of paternal alleles in the PWS region of chromosome 15. The PWS phenotype resembles that observed in the classic non-PWS GH deficiency (GHD), including short stature, excessive fat mass, and reduced muscle mass. To date, a small number of studies on the long-term effects of GH treatment are available in adult subjects with PWS.

Methods

In this longitudinal study, 12 obese subjects with PWS (GHD/non-GHD 6/6) were treated for a median of 17 years, with a median GH dose of 0.35 mg/day. The median age was 27.1 years. Anthropometric, body composition, hormonal, biochemical, and blood pressure variables were analyzed in all subjects.

Results

Waist circumference was significantly lower at the end of the treatment period (p-value=0.0449), while body mass index (BMI) did not differ significantly. Compared to the baseline, a highly significant reduction of Fat Mass % (FM%) was observed (p-value=0.0005). IGF-I SDS values significantly increased during GH therapy (p-value=0.0005). A slight impairment of glucose homeostasis was observed after GH therapy, with an increase in the median fasting glucose levels, while insulin, HOMA-IR, and HbA1c values remained unchanged. Considering GH secretory status, both subjects with and without GHD showed a significant increase in IGF-I SDS and a reduction of FM% after GH therapy (p-value= 0.0313 for all).

Discussion

Our results indicate that long-term GH treatment has beneficial effects on body composition and body fat distribution in adults with PWS associated with obesity. However, the increase in glucose values during GH therapy should be considered, and continuous surveillance of glucose metabolism is mandatory during long-term GH therapy, especially in subjects with obesity.

Acute stress response of the HPA-axis in children with Prader-Willi syndrome: new insights and consequences for clinical practice

Background

Prader-Willi syndrome (PWS) is associated with hypothalamic dysfunction. It has been reported that the HPA axis might show a delayed response during acute stress, and it is unknown whether the response of the HPA-axis during acute stress changes with age in children with PWS.

Aim

To investigate the HPA-axis response during an overnight single-dose metyrapone (MTP) test in children with PWS and to assess if the response changes with age, whether it is delayed and if it changes with repeated testing over time. In addition, we evaluated different cut-off points of ACTH and 11-DOC levels to assess stress-related central adrenal insufficiency (CAI).

Methods

An overnight single-dose MTP test was performed in 93 children with PWS. Over time, 30 children had a second test and 11 children a third one. Children were divided into age groups (0-2 years, 2-4 years, 4-8 years and > 8 years).

Results

Most children did not have their lowest cortisol level at 7.30h, but at 04.00h. Their ACTH and 11-DOC peaks appeared several hours later, suggesting a delayed response. When evaluated according to a subnormal ACTH peak (13-33 pmol/L) more children had an subnormal response compared to evaluation based on a subnormal 11-doc peak (< 200 nmol/L). The percentage of children with a subnormal ACTH response ranged from 22.2 to 70.0% between the age groups, while the percentage of a subnormal 11-DOC response ranged from 7.7 to 20.6%. When using the ACTH peak for diagnosing acute-stress-related CAI, differences between age groups and with repeated testing over time were found, whereas there was no age difference when using the 11-DOC peak.

Conclusion

Early morning ACTH or 11-DOC levels are not appropriate to determine acute stress-related CAI in children with PWS, thus multiple measurements throughout the night are needed for an accurate interpretation. Our data suggest a delayed response of the HPA-axis during acute stress. Using the 11-DOC peak for the test interpretation is less age-dependent than the ACTH peak. Repeated testing of the HPA-axis over time is not required, unless clinically indicated.

Central precocious puberty in Prader-Willi syndrome: a narrative review

Prader-Willi syndrome (PWS, OMIM176270) is a rare genetic disorder with recognizable dysmorphic features and multisystemic consequences such as endocrine, neurocognitive and metabolic ones. Although most patients with Prader-Willi syndrome exhibit hypogonadotropic hypogonadism, there is variability regarding sexual maturation, with precocious puberty occurring in rare cases. Our aim is to elaborate a thorough review of Prader-Willi patients with central precocious puberty, in order to raise awareness of such cases and to enhance our knowledge regarding the diagnosis and prompt treatment of this particular PWS patients.

Early recombinant human growth hormone treatment improves mental development and alleviates deterioration of motor function in infants and young children with Prader-Willi syndrome

BACKGROUND

Recombinant human growth hormone (rhGH) therapy has shown to improve height and body composition in children with Prader-Willi syndrome (PWS), the evidence of early rhGH treatment on motor and mental development is still accumulating. This study explored the time effect on psychomotor development, anthropometric indexes, and safety for infants and young children with PWS.

METHODS

A phase 3, single-arm, multicenter, self-controlled study was conducted in six sites. Patients received rhGH at 0.5 mg/m2/day for first four weeks, and 1 mg/m2/day thereafter for up to 52 weeks. Motor development was measured using Peabody Developmental Motor Scales-second edition, mental development using Griffiths Development Scales-Chinese (GDS-C). Height standard deviation score (SDS), body weight SDS, and body mass index (BMI) SDS were also assessed.

RESULTS

Thirty-five patients were enrolled totally. Significant improvements were observed in height, body weight, and BMI SDS at week 52; GDS-C score showed significant improvement in general quotient (GQ) and sub-quotients. In a linear regression analysis, total motor quotient (TMQ), gross motor quotient (GMQ), and fine motor quotient were negatively correlated with age; however, treatment may attenuate deterioration of TMQ and GMQ. Changes in GQ and locomotor sub-quotient in < 9-month group were significantly higher than ≥ 9-month group. Mild to moderate severity adverse drug reactions were reported in six patients.

CONCLUSION

Fifty-two-week treatment with rhGH improved growth, BMI, mental development, and lessened the deterioration of motor function in infants and young children with PWS. Improved mental development was more pronounced when instituted in patients < 9 months old.

Insulin secretion deficits in a Prader-Willi syndrome β-cell model are associated with a concerted downregulation of multiple endoplasmic reticulum chaperones

Prader-Willi syndrome (PWS) is a multisystem disorder with neurobehavioral, metabolic, and hormonal phenotypes, caused by loss of expression of a paternally-expressed imprinted gene cluster. Prior evidence from a PWS mouse model identified abnormal pancreatic islet development with retention of aged insulin and deficient insulin secretion. To determine the collective roles of PWS genes in β-cell biology, we used genome-editing to generate isogenic, clonal INS-1 insulinoma lines having 3.16 Mb deletions of the silent, maternal- (control) and active, paternal-allele (PWS). PWS β-cells demonstrated a significant cell autonomous reduction in basal and glucose-stimulated insulin secretion. Further, proteomic analyses revealed reduced levels of cellular and secreted hormones, including all insulin peptides and amylin, concomitant with reduction of at least ten endoplasmic reticulum (ER) chaperones, including GRP78 and GRP94. Critically, differentially expressed genes identified by whole transcriptome studies included reductions in levels of mRNAs encoding these secreted peptides and the group of ER chaperones. In contrast to the dosage compensation previously seen for ER chaperones in Grp78 or Grp94 gene knockouts or knockdown, compensation is precluded by the stress-independent deficiency of ER chaperones in PWS β-cells. Consistent with reduced ER chaperones levels, PWS INS-1 β-cells are more sensitive to ER stress, leading to earlier activation of all three arms of the unfolded protein response. Combined, the findings suggest that a chronic shortage of ER chaperones in PWS β-cells leads to a deficiency of protein folding and/or delay in ER transit of insulin and other cargo. In summary, our results illuminate the pathophysiological basis of pancreatic β-cell hormone deficits in PWS, with evolutionary implications for the multigenic PWS-domain, and indicate that PWS-imprinted genes coordinate concerted regulation of ER chaperone biosynthesis and β-cell secretory pathway function.

The Diagnosis and Genetic Mechanisms of Prader-Willi Syndrome: Findings From a Moroccan Population Study

Background Prader-Willi syndrome (PWS) is a complex genetic disorder caused by a deficit in gene expression on the paternal inherited chromosome 15q11.2-q13. It affects various aspects of growth and development, including feeding, cognitive function, and behavior. Early diagnosis and management of PWS can significantly improve outcomes for patients and their families. Methods In this study, we analyzed a group of 29 clinically diagnosed patients suspected of PWS. All patients were referred to the medical genetics and onco-genetics service for genetic consultation and molecular analysis. We used DNA methylation analysis and fluorescence in situ hybridization (FISH) to confirm the diagnosis and identify the underlying genetic mechanisms. Results Our analysis showed that five out of seven patients (71.43%) with a positive methylation-specific PCR (MSP) had chromosomal deletion by FISH and presented major clinical signs summarized by morbid obesity in 65.21% of cases and neonatal hypotonia in 42.85% of cases. This finding indicates that paternal 15q11-q13 deletion is the most common genetic mechanism involved in PWS. Conclusion The results of this study highlight the importance of early diagnosis and molecular analysis in the management of Prader-Willi syndrome. Our findings contribute to a better understanding of the genotype-phenotype correlation in the Moroccan population and provide families with a rigorous molecular diagnosis, relevant genetic counseling, and multidisciplinary support. Further research is needed to explore the underlying mechanisms of PWS and develop effective interventions to improve outcomes for affected individuals.

The Effects of 5 Years of Growth Hormone Treatment on Growth and Body Composition in Patients with Temple Syndrome

INTRODUCTION

Temple syndrome (TS14) is a rare imprinting disorder caused by maternal uniparental disomy of chromosome 14, paternal deletion of 14q32.2, or an isolated methylation defect. Most patients with TS14 develop precocious puberty. Some patients with TS14 are treated with growth hormone (GH). However, evidence for the effectiveness of GH treatment in patients with TS14 is limited.

METHODS

This study describes the effect of GH treatment in 13 children and provides a subgroup analysis of 5 prepubertal children with TS14. We studied height, weight, body composition by dual-energy X-ray absorptiometry, resting energy expenditure (REE), and laboratory parameters during 5 years of GH treatment.

RESULTS

In the entire group, mean (95% CI) height SDS increased significantly during 5 years of GH treatment from -1.78 (-2.52; -1.04) to 0.11 (-0.66; 0.87). Fat mass percentage SDS decreased significantly during the first year of GH, and lean body mass (LBM) SDS and LBM index increased significantly during 5 years of treatment. IGF-1 and IGF-BP3 levels rose rapidly during GH treatment, and the IGF-1/IGF-BP3 molar ratio remained relatively low. Thyroid hormone levels, fasting serum glucose, and insulin levels remained normal. In the prepubertal group, median (interquartile range [IQR]) height SDS, LBM SDS, and LBM index also increased. REE was normal at start and did not change during 1 year of treatment. Five patients reached adult height and their median (IQR) height SDS was 0.67 (-1.83; -0.01).

CONCLUSION

GH treatment in patients with TS14 normalizes height SDS and improves body composition. There were no adverse effects or safety concerns during GH treatment.

Positive effects of ketogenic diet on weight control in children with obesity due to Prader-Willi syndrome

OBJECTIVE

Prader-Willi Syndrome (PWS) is the most common genetic cause of obesity. Prevention and management of obesity, which represents the main cause of morbidity and mortality in these patients, is essential. Ketogenic diet (KD) is used in the treatment of various disorders, however knowledge of its effect in PWS is lacking. The present study assesses the characteristics of patients with PWS who were on KD.

DESIGN AND PATIENTS

This is a retrospective, cross-sectional descriptive study investigating the subjects with PWS, who had received KD for at least 6 months.

RESULTS

Ten patients with PWS [median age 52.5 (47-77) months] complied with KD. The median treatment period was 16.5 [11-52] months. Of the daily calorie, 75%-85% were from fat, and 15%-25% from protein + carbohydrate. The baseline body weight standard deviation (SD) score before diet therapy was 2.10 [-1.11-4.11], whereas it was 0.05 [-0.92-1.2] at final evaluation (p = .007). The baseline median BMI SD score before diet therapy was 3.05 [-0.21-3.72], whereas it was 0.41 [-0.87-1.57] at final evaluation (p = .002). The height SD score remained unchanged. Mild hypercholesterolaemia was the most common biochemical abnormality during treatment with KD.

CONCLUSION

Our results indicate that KD might have a favourable effect on weight management in PWS.

Sleep Consequences of Prader-Willi Syndrome

PURPOSE OF REVIEW

This paper reviews how sleep is impacted in patients with Prader-Willi syndrome (PWS), focusing on sleep-related breathing disturbances and excessive daytime sleepiness (EDS).

RECENT FINDINGS

Hypothalamic dysfunction may underlie several aspects of the PWS phenotype. Central sleep apnea (CSA) can persist beyond infancy. Nocturnal hypoventilation is common and may occur without central or obstructive sleep apnea (OSA). Adenotonsillectomy, a mainstay of OSA treatment, may cause velopharyngeal insufficiency. Growth hormone (GH) is considered safe, but close surveillance for OSA remains important. Cardiac autonomic dysfunction occurs during slow wave sleep and may increase the risk of cardiovascular events. EDS and narcolepsy are also common. Modafinil and pitolisant are treatment options currently being studied. Sleep disorders are prevalent in individuals with PWS. Sleep-related breathing disorders present as CSA in infancy and later in life as OSA and hypoventilation. GH therapy has improved the clinical outcomes of patients with PWS, but close surveillance and treatment for OSA is recommended. EDS can persist even after sleep-related breathing disorders are treated, and some individuals may even develop narcolepsy. Early recognition and treatment of sleep-related disorders may prevent morbidity and result in improved survival of patients with PWS.

Premature adrenarche in Prader-Willi syndrome is associated with accelerated pre-pubertal growth and advanced bone age

OBJECTIVES

Prader-Willi syndrome (PWS) is characterized by obesity, growth hormone deficiency, hypogonadism, and a high prevalence of premature adrenarche despite reported hypothalamic-pituitary-adrenal axis dysfunction. While idiopathic premature adrenarche is associated with accelerated pre-pubertal growth and advanced bone age, the consequences of elevated adrenal androgens on growth and bone maturation in PWS remain unknown. This study therefore sought to describe age-related changes in dehydroepiandrosterone sulfate (DHEAS) and their effects on growth and bone maturation in PWS.

METHODS

This retrospective observational study included 62 children with PWS. Simple and multiple regression models were constructed to relate age and BMI-SDS with DHEAS levels. Height velocity was compared to age and sex-based norms with t-tests and two-way ANOVA. Patterns in bone age Z-score were examined with two-way ANOVA, and the contributions of age, BMI-SDS, and DHEAS to bone age Z-score were analyzed with multiple regression.

RESULTS

DHEAS levels rose earlier and were less strongly correlated with age in males and females with PWS (R²=0.12 and 0.30) compared to healthy controls (R²=0.89 and 0.88) in a pattern unrelated to BMI-SDS (adjusted R²=0.076, p=0.10 for age, and 0.29 for BMI-SDS). Mid-childhood height velocity was increased in males and preserved in females with PWS before declining at the age of expected puberty (p<0.0001). Peri-adrenarchal bone age was advanced in a manner associated with DHEAS but not BMI-SDS (p<0.0001; adjusted R²=0.48, p=0.0014 for DHEAS, and 0.78 for BMI-SDS).

CONCLUSIONS

An obesity-independent increase in adrenal androgens is associated with accelerated mid-childhood growth and bone maturation in PWS.

The Italian registry for patients with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a rare and complex genetic disease, with numerous implications on metabolic, endocrine, neuropsychomotor systems, and with behavioural and intellectual disorders. Rare disease patient registries are important scientific tools (1) to collect clinical and epidemiologic data, (2) to assess the clinical management including the diagnostic delay, (3) to improve patients' care and (4) to foster research to identify new therapeutic solutions. The European Union has recommended the implementation and use of registries and databases. The main aims of this paper are to describe the process of setting up the Italian PWS register, and to illustrate our preliminary results.

MATERIALS AND METHODS

The Italian PWS registry was established in 2019 with the aims (1) to describe the natural history of the disease, (2) to determine clinical effectiveness of health care services, (3) to measure and monitor quality of care of patients. Information from six different variables are included and collected into this registry: demographics, diagnosis and genetics, patient status, therapy, quality of life and mortality.

RESULTS

A total of 165 patients (50.3% female vs 49.7% male) were included into Italian PWS registry in 2019-2020 period. Average age at genetic diagnosis was 4.6 years; 45.4% of patients was less than 17 years old aged, while the 54.6% was in adult age (> 18 years old). Sixty-one percent of subjects had interstitial deletion of the proximal long arm of paternal chromosome 15, while 36.4% had uniparental maternal disomy for chromosome 15. Three patients presented an imprinting centre defect and one had a de novo translocation involving chromosome 15. A positive methylation test was demonstrated in the remaining 11 individuals but the underlying genetic defect was not identified. Compulsive food-seeking and hyperphagia was present in 63.6% of patients (prevalently in adults); 54.5% of patients developed morbid obesity. Altered glucose metabolism was present in 33.3% of patients. Central hypothyroidism was reported in 20% of patients; 94.7% of children and adolescents and 13.3% of adult patients is undergoing GH treatment.

CONCLUSIONS

The analyses of these six variables allowed to highlight important clinical aspects and natural history of PWS useful to inform future actions to be taken by national health care services and health professionals.

Effects of early recombinant human growth hormone treatment in young Chinese children with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a rare and multisystemic genetic disorder that is characterized by severe hypotonia, hyperphagia, short stature, and global developmental delay. Although early recombinant human growth hormone (rhGH) treatment has been proven to rescue some symptoms and bring additional benefits to PWS patients, studies in patients under 2 years old are scarce. Thus, this study aims to investigate the effectiveness and safety of rhGH treatment for young children.

METHODS

A total of 96 genetically confirmed Chinese PWS infants or toddlers (47 males) followed between 2013 and 2022 were retrospectively analyzed. Sixty-five infants (early treatment group) started rhGH treatment during their first year, and 31 toddlers (later treatment group) started at the age of 1-2 years. Auxological parameters, carbohydrate metabolism parameters, thyroid function, liver function, insulin-like growth factor-1 (IGF-1), and radiographs were acquired before the initiation of the treatment and every 3-6 months thereafter. Height/length, weight, and weight for height were expressed as standard deviation scores (SDSs) according to WHO child growth standards.

RESULTS

The mean SDS of length/height in the early treatment group was significantly higher than that in the later treatment group throughout the observation period (all P < 0.001). The change in the length SDS between the two groups at 1 year old and 4 years old was 1.50 (95% CI, 0.88-2.13) and 0.63 (95% CI, 0.16-1.10), respectively. Compared to the later treatment group, the weight SDS in the early treatment group increased by 0.94 (95% CI, 0.37-1.52) at 1 year old and 0.84 (95% CI, 0.28-1.39) at 2 years old. No statistical significance was found after 2.5 years of age. No significant differences were observed in IGF-1, incidence of liver dysfunction, hypothyroidism or spinal deformity between the two groups.

CONCLUSIONS

rhGH treatment improved growth and body composition in infants and toddlers. Furthermore, an early start of rhGH treatment is expected to have more efficacy than the later treatment group without an increase in adverse effects.

Facilitating the transition from paediatric to adult care in endocrinology: a focus on growth disorders

PURPOSE OF REVIEW

Many childhood-onset growth disorders (COGDs) require continued care into adulthood, and the time of transition between paediatric and adult providers carries a high risk for interruptions in medical care and consequent worsening of disease management.

RECENT FINDINGS

Research into best practices for healthcare transition (HCT) describes three distinct stages. Stage 1, transition planning and preparation, begins in the paediatric setting during early adolescence and ensures that the patient has adequate medical knowledge, self-management skills, and readiness for transition. Stage 2, transfer to adult care, occurs with variable timing depending on transition readiness and is best facilitated by warm hand-offs and, when possible, joint visits with the paediatric and adult provider(s) and/or involvement of a care coordinator. Stage 3, intake and integration into adult care, entails retaining the patient in the adult setting, ideally through the involvement of a multidisciplinary approach.

SUMMARY

This review covers general principles for ensuring smooth transition of adolescents and young adults (AYA) with COGD, disease-specific medical considerations for paediatric and adult endocrinologists during the transition process, and general and disease-specific resources to assess transition readiness and facilitate transition.

The transition from pediatric to adult care in individuals with Prader-Willi syndrome

Prader-Willi syndrome (PWS), the most common form of syndromic obesity, is a complex neurodevelopmental genetic disorder including obesity with hyperphagia, endocrine and metabolic disorders and also psychiatric disorders. The most frequent endocrine disturbances include hypogonadism and growth hormone (GH) deficiency. Hypothyroidism and central adrenal insufficiency can also be observed but are less frequent. The transition of individuals with PWS from adolescence to adult life is challenging because of multiple comorbidities and complex disabilities. Individuals and caregivers face psychological, medical and social issues. This period of profound changes is thus prone to disruptions, and the main risks being the worsening of the medical situation and loss to follow-up of the individuals. Medical care may be poorly adapted to the needs of individuals because of a lack of knowledge concerning the syndrome and also lack of the necessary specific skills. A multidisciplinary panel composed of several experts in PWS met in November 2021 during an European Reference Network on Rare Endocrine Conditions (Endo-ERN) webinar. They presented complementary aspects of PWS from the perspective of the transition including psychiatric, pediatric and adult endocrinological and parent's and patient's points of view and shed light on the best way to approach this pivotal period.

A rare occurrence of non-classic congenital adrenal hyperplasia and type 1 diabetes mellitus in a girl with Prader-Willi Syndrome: Case report and review of the literature

Prader-Willi syndrome (PWS) is a rare genetic disorder resulting from lack of expression of the paternally derived chromosome 15q11-13, associated with several complications, including pubertal disorders, short stature, hyperphagia, obesity, glucose metabolism abnormalities, scoliosis, obstructive sleep apnea syndrome (OSAS) and behavioral problems. We report the case of a girl affected by PWS who presented at the age of 5.9 with premature pubarche, accelerated linear growth and advanced bone age (BA). She was subsequently diagnosed with non-classic congenital adrenal hyperplasia (CAH) confirmed by genetic analysis. Considering the clinical, biochemical, and genetic findings, hydrocortisone therapy was started to prevent rapid BA acceleration and severe compromission of final height. During infancy, short stature and low levels of insulin-like growth factor-1 (IGF-1) for age and gender led to suspicion of growth hormone deficiency (GHD), confirmed by stimulation testing (arginine and clonidine). rhGH therapy was administered and continued until final height was reached. During endocrinological follow up she developed impaired glucose tolerance with positive markers of β-cell autoimmunity (anti-glutamic acid decarboxylase antibodies, GAD Ab), which evolved over time into type 1 diabetes mellitus and insulin therapy with a basal-bolus scheme and an appropriate diet were needed.

Hypothalamic AAV-BDNF gene therapy improves metabolic function and behavior in the Magel2-null mouse model of Prader-Willi syndrome

Individuals with Prader-Willi syndrome (PWS) display developmental delays, cognitive impairment, excessive hunger, obesity, and various behavioral abnormalities. Current PWS treatments are limited to strict supervision of food intake and growth hormone therapy, highlighting the need for new therapeutic strategies. Brain-derived neurotrophic factor (BDNF) functions downstream of hypothalamic feeding circuitry and has roles in energy homeostasis and behavior. In this preclinical study, we assessed the translational potential of hypothalamic adeno-associated virus (AAV)-BDNF gene therapy as a therapeutic for metabolic dysfunction in the Magel2-null mouse model of PWS. To facilitate clinical translation, our BDNF vector included an autoregulatory element allowing for transgene titration in response to the host's physiological needs. Hypothalamic BDNF gene transfer prevented weight gain, decreased fat mass, increased lean mass, and increased relative energy expenditure in female Magel2-null mice. Moreover, BDNF gene therapy improved glucose metabolism, insulin sensitivity, and circulating adipokine levels. Metabolic improvements were maintained through 23 weeks with no adverse behavioral effects, indicating high levels of efficacy and safety. Male Magel2-null mice also responded positively to BDNF gene therapy, displaying improved body composition, insulin sensitivity, and glucose metabolism. Together, these data suggest that regulating hypothalamic BDNF could be effective in the treatment of PWS-related metabolic abnormalities.

Prader-Willi Syndrome in Adults: An Update On Nutritional Treatment and Pharmacological Approach

PURPOSE OF REVIEW

Prader-Willi syndrome (PWS) is a rare and complex genetic disorder with multiple effects on the metabolic, endocrine, and neurological systems, as well as behavioral and intellectual difficulties. Despite advances in understanding the genetic basis of obesity in PWS, there are conflicting data on its management. Therefore, the present manuscript aims to provide an update on the nutritional treatment and pharmacological approach in adult patients with PWS.

RECENT FINDINGS

The management of obesity in patients with PWS is challenging and requires the cooperation of an experienced multidisciplinary team, including the nutritionist. An adequate clinical evaluation including nutritional and biochemical parameters should be performed to tailor the best therapeutic strategy. Both lifestyle and pharmacological interventions may represent useful strategies to prevent the high rate of morbidity and mortality related to PWS. The use of bariatric surgery is still controversial. Although it is imperative to adopt an obesity prevention strategy in childhood, there is promising evidence for the treatment of obesity in adulthood with current obesity medications in conjunction with lifestyle interventions.

Novel Case of Prader–Willi Syndrome and Ebstein's Anomaly: Implications for Complex Care Management

We present a patient with a complex phenotype including diagnoses of Ebstein's anomaly and Prader–Willi syndrome (PWS) as well as additional congenital anomalies and genetic variants with potential clinical effects. This is the first reported case of both diagnoses present in the same patient. The diagnosis of Ebstein's anomaly was made on prenatal ultrasound. She presented with neonatal hypotonia, feeding problems, and dysmorphic features, followed by later onset weight gain, leading to a diagnosis of PWS. Further evaluations revealed Blaschkoid hyperpigmentation, laryngeal cleft, and pigmentary retinopathy. Whole exome sequencing determined a likely pathogenic variant in alkaline phosphatase gene and several mitochondrial DNA variants. We discuss the known genetic mechanisms of PWS and compare them to the heterogenous genetic associations of Ebstein's anomaly. The standard of care treatment for PWS is growth hormone therapy, which is associated with right-sided heart failure risks. This case illustrates the need to complete the diagnostic work up in all patients, as well as the necessity of a multidisciplinary approach for optimal outcomes.

Preserved Sleep for the Same Level of Respiratory Disturbance in Children with Prader-Willi Syndrome

Debate remains as to how to balance the use of recombinant human growth hormone (rhGH) as an important treatment in Prader-Willi syndrome (PWS) with its potential role in obstructive sleep apnea. This single-center, retrospective study assessed differences in overnight polysomnography results between children with and without PWS and changes in respiratory parameters before and after the initiation of rhGH treatment in those with PWS. Compared with age-, sex-, and body-mass-index-matched controls (n = 87), children with PWS (n = 29) had longer total sleep time (434 ± 72 vs. 365 ± 116 min; p < 0.01), higher sleep efficiency (86 ± 7 vs. 78 ± 15%; p < 0.05), and lower arousal events (8.1 ± 4.5 vs. 13.0 ± 8.9 events/h; p < 0.05). Mean oxygen saturation was lower in PWS children (94.3 ± 6.0 vs. 96.0 ± 2.0%; p < 0.05), with no other differences in respiratory parameters between groups. Eleven children with PWS (38%) met the criteria for further analyses of the impact of rhGH; polysomnography parameters did not change with treatment. Compared with other children undergoing polysomnography, children with PWS had more favorable markers of sleep continuity and lower oxygen saturation for the same level of respiratory disturbance. rhGH administration was not associated with changes in respiratory parameters in PWS.

Atypical 15q11.2-q13 Deletions and the Prader-Willi Phenotype

Background: Prader-Willi syndrome (PWS) is a rare genetic disorder resulting from the lack of expression of the PWS region (locus q11-q13) on the paternally derived chromosome 15, as a result of a type I or II paternal deletion (50%), maternal uniparental disomy (43%), imprinting defect (4%) or translocation (<1%). In very rare cases, atypical deletions, smaller or larger than the typical deletion, are identified. These patients may have distinct phenotypical features and provide further information regarding the genotype−phenotype correlation in PWS. Methods: A prospective study in eight patients (six males and two females) with an atypical deletion in the PWS region accompanies an overview of reported cases. Results: All patients had hypotonia (100%) and many had typical PWS facial characteristics (75%), social and emotional developmental delays (75%), intellectual disabilities (50%), neonatal feeding problems and tube feeding (63%), history of obesity (50%), hyperphagia (50%) and scoliosis (50%). All males had cryptorchidism. Two patients had two separate deletions in the PWS critical region. Conclusions: Our findings provide further insight into PWS genotype−phenotype correlations; our results imply that inclusion of both SNURF-SNPRN and SNORD-116 genes in the deletion leads to a more complete PWS phenotype. A larger deletion, extending further upstream and downstream from these genes, does not cause a more severe phenotype. Conventional PWS methylation testing may miss small deletions, which can be identified using targeted next generation sequencing. PWS’s phenotypic diversity might be caused by differentially methylated regions outside the 15q11.2 locus.

Reference Genes across Nine Brain Areas of Wild Type and Prader-Willi Syndrome Mice: Assessing Differences in Igfbp7, Pcsk1, Nhlh2 and Nlgn3 Expression

Prader−Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by the deletion or inactivation of paternally expressed imprinted genes at the chromosomal region 15q11−q13. The PWS-critical region (PWScr) harbors tandemly repeated non-protein coding IPW-A exons hosting the intronic SNORD116 snoRNA gene array that is predominantly expressed in brain. Paternal deletion of PWScr is associated with key PWS symptoms in humans and growth retardation in mice (PWScr model). Dysregulation of the hypothalamic−pituitary axis (HPA) is thought to be causally involved in the PWS phenotype. Here we performed a comprehensive reverse transcription quantitative PCR (RT-qPCR) analysis across nine different brain regions of wild-type (WT) and PWScr mice to identify stably expressed reference genes. Four methods (Delta Ct, BestKeeper, Normfinder and Genorm) were applied to rank 11 selected reference gene candidates according to their expression stability. The resulting panel consists of the top three most stably expressed genes suitable for gene-expression profiling and comparative transcriptome analysis of WT and/or PWScr mouse brain regions. Using these reference genes, we revealed significant differences in the expression patterns of Igfbp7, Nlgn3 and three HPA associated genes: Pcsk1, Pcsk2 and Nhlh2 across investigated brain regions of wild-type and PWScr mice. Our results raise a reasonable doubt on the involvement of the Snord116 in posttranscriptional regulation of Nlgn3 and Nhlh2 genes. We provide a valuable tool for expression analysis of specific genes across different areas of the mouse brain and for comparative investigation of PWScr mouse models to discover and verify different regulatory pathways affecting this complex disorder.

Recommendations for the diagnosis and management of childhood Prader-Willi syndrome in China

Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disease, which is caused by the lack of expression of paternally inherited imprinted genes on chromosome15q11.2-q13.1. The clinical manifestations of PWS vary with age. It is characterized by severe hypotonia with poor suck and feeding difficulties in the early infancy, followed by overeating in late infancy or early childhood and progressive development of morbid obesity unless the diet is externally controlled. Compared to Western PWS patients, Chinese patients have a higher ratio of deletion type. Although some rare disease networks, including PWS Cooperation Group of Rare Diseases Branch of Chinese Pediatric Society, Zhejiang Expert Group for PWS, were established recently, misdiagnosis, missed diagnosis and inappropriate intervention were usually noted in China. Therefore, there is an urgent need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy. Our purpose is to evaluate the current literature and evidences on diagnosis and management of PWS in order to provide evidence-based guidelines for this disease, specially from China.

A Review of Prader–Willi Syndrome

Prader–Willi Syndrome (PWS, OMIM #176270) is a rare complex genetic disorder due to the loss of expression of paternally derived genes in the PWS critical region on chromosome 15q11-q13. It affects multiple neuroendocrine systems and may present failure to thrive in infancy, but then, hyperphagia and morbid obesity starting in early childhood became the hallmark of this condition. Short stature, hypogonadism, sleep abnormalities, intellectual disability, and behavioral disturbances highlight the main features of this syndrome. There have been a significant number of advances in our understanding of the genetic mechanisms underlying the disease, especially discoveries of MAGEL2, NDN, MKRN3, and SNORD116 genes in the pathophysiology of PWS. However, early diagnosis and difficulty in treating some of the disease’s most disabling features remain challenging. As our understanding of PWS continues to grow, so does the availability of new therapies and management strategies available to clinicians and families.

Subcutaneous adipose tissue is a positive predictor for bone mineral density in prepubertal children with Prader-Willi syndrome independent of lean mass

OBJECTIVES

Emerging evidence suggests a fat depot-specific relationship with bone mineral density (BMD) in children, particularly in those who are overweight/obese. However, this has not yet been investigated in detail in children with Prader-Willi syndrome (PWS), a genetic syndrome characterized by a decreased lean mass (LM) and increased fat mass (FM). The objective of this study is to investigate the relationships of LM and FM, particularly fat distribution, with bone mineral parameters.

METHODS

This is a retrospective and cross-sectional study. Forty-seven prepubertal Japanese children with PWS (22 males, mean age: 6.86 years) were included. No subjects had type 2 diabetes mellitus or osteoporotic medications. LM, FM, and BMD and bone mineral content in the total body less head and the lumbar spine were measured using dual-energy x-ray absorptiometry, in addition to subcutaneous/visceral adipose tissue (SAT/VAT), and the ratio of VAT to SAT (V/S) by computed tomography at the umbilical level. Bone mineral apparent density was calculated to correct for bone size.

RESULTS

LM positively correlated with bone mineral parameters after controlling for age, sex, growth hormone (GH) treatment, and FM. Although FM did not correlate with bone mineral parameters, compartment-specific analysis revealed that SAT positively and V/S negatively correlated with bone mineral parameters after controlling for age, sex, GH treatment and LM.

CONCLUSIONS

A compartment-specific effect of FM on bone mineral parameters was noted such that SAT was a positive predictor for BMD independent of LM in prepubertal children with PWS.

Approach to the Patient With Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a rare, multisystemic, genetic disorder involving the hypothalamus. It is caused by loss of expression of paternally inherited genes in chromosome 15 q11-13 region. The estimated incidence is around 1 in 20.000 births. PWS is characterized by a complex lifelong trajectory involving neurodevelopmental, nutritional, endocrine, metabolic, and behavioral changes. The major symptoms are hypotonia, short stature, hypogonadism, and eating disorders ranging from anorexia in infancy to hyperphagia, a deficit of satiety, and a high risk of severe obesity. The patients display intellectual disability comprising cognitive deficit, delayed motor and language development, learning deficits, impaired social skills, and emotional regulation. Behavioral features including temper outbursts, anxiety, obsessive-compulsive symptoms and rigidity are common and become more apparent with increasing age. Almost all have hypogonadism and growth hormone deficiency. Central adrenal insufficiency is rare whereas central hypothyroidism occurs in up to 30% of children with PWS. The prevalence of obesity increases with age from almost none in early childhood to more than 90% in adulthood. Up to 25% of adults with obesity have type 2 diabetes. Obesity and its complications are the major causes of comorbidity and mortality in PWS. As there is no specific treatment, care consists of comprehensive management of feeding disorders, a restricted, controlled diet, regular exercise, hormone substitution, and screening and treatment of comorbidities. Here we present the course of PWS from birth to adulthood in 2 patients and discuss their symptoms in relation to the literature.

Thyroid function in children with Prader-Willi syndrome in Southern China: a single-center retrospective case series

Background

To investigate hypothalamic-pituitary-thyroid function in children of different ages, nutritional phases, and genotypes that were diagnosed with Prader-Willi syndrome (PWS), as well as the effects of recombinant human growth hormone (rhGH) treatment on thyroid hormones in PWS patients.

Methods

One hundred and thirty PWS patients (87 boys and 43 girls) aged from newborn to 15 years (y) (median 1.25 y, mean, SD: 2.95 ± 3.45 y), were surveyed in this study. Serum thyroid hormone levels were examined at least once per3-6 months during the 2 years follow-up study. Central hypothyroidism (C-HT) was identified as low/normal thyroid-stimulating hormone (TSH) and low free thyroxine 4 (FT4).

Results

All study participants had normal neonatal TSH screening test results. The prevalence of C-HT is 36.2% (47/130). No C-HT cases were diagnosed in PWS either below 1 month (m) or above 12 y. The prevalence of C-TH would be increased with age before 3 y until reaching the peak, followed by a gradual decline over the years. The prevalence of C-HT varies significantly at different ages (Pearson's χ2 = 19.915; p < 0.01). However, there is no correlation between the C-HT prevalence and nutritional phases (Pearson's χ2 = 4.992; p = 0.288), genotypes (Pearson's χ2 = 0.292; p = 0.864), or rhGH therapy (Pearson's χ2 = 1.799; p = 0.180).

Conclusions

This study suggests the prevalence of C-TH was increased with the age before 3 y, and reached the peak in the 1 to 3 y group, then gradually declined over the years. There is no correlation between C-HT prevalence and nutritional phases, genotypes, or rhGH treatment.

Long-Term Growth Hormone Treatment of Children with PWS: The Earlier the Start, the Better the Outcomes?

Long-term effects of growth hormone (GH) treatment in young children with Prader-Willi syndrome (PWS) have never been compared with untreated age-matched controls with PWS, and it is unclear if starting GH in the first year of life is safe and more effective than starting GH in early childhood. We investigated the effects of long-term GH on body composition, anthropometrics and cognition in young children with PWS compared to untreated controls and assessed whether starting GH in the first year of life is optimal and safe. An open-label, prospective study was performed, comparing GH-treated children with untreated controls, and comparing children who started GH in the first year of life (subgroup A) with children who started between 2–5 years (subgroup C). A total of 82 GH-treated children with PWS and 22 age-matched controls with PWS were included. The main outcome measures were body composition, anthropometrics, IQ, and safety parameters. After 8 years, GH-treated children had significantly better body composition and were taller than age-matched controls. Subgroup A had a lower FM% trajectory during treatment than subgroup C and showed a greater and longer-term increase in the LBM index. After 8 years, subgroup A had a lower trunk/peripheral fat ratio (p = 0.043) and higher IQ (p = 0.043). No adverse effects of starting GH in the first year were found. Children with PWS who received long-term GH had a better body composition and growth than untreated age-matched controls and starting GH in the first year of life was optimal and safe.