PRADER-WILLI SYNDROME: WHAT IS THE GENERAL PEDIATRICIAN SUPPOSED TO DO? - A REVIEW

A review of Prader-Willi syndrome

ABSTRACT

Prader-Willi syndrome is a rare and complex genetic disorder with multiple physical and behavioral characteristics, affecting endocrine, metabolic, and neurologic systems and producing a plethora of medical complications. Early identification and diagnosis are paramount to providing timely and appropriate interventions to improve patient outcomes. Treatment should focus on neonatal feeding and growth, followed by hormonal therapy for hypothalamic dysfunction, and should then be directed at the prevention and treatment of obesity and obesity-related complications. Effective treatment requires a comprehensive multidisciplinary approach.

Growth hormone treatment in children with Prader-Willi syndrome: safety and effectiveness data from the PATRO Children study

Background

Recombinant human growth hormone (rhGH, somatropin) therapy is approved in children with Prader-Willi syndrome (PWS).

Objectives

To report safety and effectiveness data for children with PWS treated with biosimilar rhGH (Omnitrope®, Sandoz) in the PAtients TReated with Omnitrope (PATRO) Children study.

Design

PATRO Children was a multicenter, non-interventional, postmarketing surveillance study.

Methods

Children with PWS received Omnitrope according to standard clinical practice. Adverse events (AEs) were monitored for the duration of Omnitrope treatment. Effectiveness outcomes were also assessed, including height standard deviation (SD) scores (HSDS).

Results

As of July 2020 (study completion), 235 patients with PWS had been enrolled. At baseline, 95.7% (n = 225) of patients were prepubertal and 86.4% (n = 203) were rhGH treatment-naïve. At analysis, the median (range) treatment duration in the study was 56.8 (2.9-155.8) months. AEs were reported in 192 patients (81.7%) and were suspected as treatment-related in 39 patients (16.6%). Serious AEs (SAEs) were reported in 96 patients (40.9%) and were suspected as treatment-related in 22 patients (9.4%). The most frequent treatment-related SAEs were sleep apnea syndrome (n = 11; 4.7%), tonsillar hypertrophy (n = 4; 1.7%), and adenoidal hypertrophy (n = 4; 1.7%). Development of scoliosis was considered treatment-related in two patients; development of impaired glucose tolerance in one patient and type 2 diabetes mellitus in another patient were considered treatment-related. Effectiveness outcomes were primarily assessed in 153 patients who completed 3 years of treatment. Among the 151 prepubertal patients (135 treatment-naïve), mean (SD) change from baseline in HSDS after 3 years was +1.50 (1.07) across all patients and +1.57 (1.07) for treatment-naïve patients.

Conclusion

These data suggest that biosimilar rhGH is well tolerated and effective in patients with PWS managed in real-life clinical practice. Patients with PWS should continue to be closely monitored for well-known safety issues (including respiratory, sleep, and glucose metabolism disorders, and scoliosis) during rhGH treatment.

Quality of Life in Children with Prader-Willi Syndrome and the Impact of the Disease on the Functioning of Families

Objective: Prader−Willi (PWS; OMIM#176270) syndrome is a clinically distinct genetic disorder, caused by an abnormality in the 15q11-q13 region, referred to as the critical region. One of the most popular concepts existing in modern sciences, not only within psychology, but also in the aspect of all sciences that are related to human life and its course, is the quality of life (QoL). Though it is known that health-related quality of life in children with PWS can be reduced, less is understood about the impact on the family. We aimed to identify factors related to the quality of life of children with PWS and the impact of the disease on family functioning. Methods: A cross-sectional questionnaire survey. The subjects were 46 parents of children with PWS. The Computer Assisted Self-Interviewing (CASI) method was used; the Paediatric Quality of Life Inventory and the PedsQL Family Impact Module. Results: The PedsQL mean score was 49.0; (min−max: 5.6−90.8; SD = 16.8), with the highest scores in the Emotional Functioning (EF) (EF; 55.9; min−max: 5.0−100.0; SD = 22.0), and the lowest in the Social Functioning (SF) (SF; 42.7; min−max: 5.0−85.0; SD = 18.7) 56.4 (SD ± 14.7). The child’s age does not affect the quality of life, there were no statistically significant (p > 0.05). families have difficulties in performing daily activities (total score 27.6; SD 16.7), support family functioning (total score 28.9; SD 18.8) and effects physical domain (total score 27.7; SD 15.7). Conclusion: Research on the QoL of patients with PWS and their families is very important in order to assess the QoL, but also to provide the perspective of an active change in the perspective of a better treatment process, rehabilitation and communication in society.

Prader-Willi syndrome: Periodontal-prosthodontic rehabilitation in an adult patient

INTRODUCTION

Prader-Willi syndrome (PWS) is a rare genetic multisystemic disease that is the most common inherited cause of severe childhood obesity. PWS patients are prone to significant oral and systemic health issues that detrimentally affect quality of life and decrease longevity. This report documents full-mouth pre-prosthetic surgical and restorative care in an adult PWS patient.

CASE REPORT

The patient, a 29-year-old male, presented to the clinic accompanied by his guardians (parents) with the chief complaint that "My Teeth are breaking down and I would like to get them fixed". Periodontal and prosthetic comprehensive clinical and radiographic exams revealed a severely worn dentition, deep anterior overbite, altered passive eruption with generalized biofilm-induced gingivitis, and altered occlusal vertical dimension. Full mouth crown lengthening surgery combined with full mouth prosthodontic reconstruction was performed under parenteral sedation and local anesthesia. Completion of treatment was successful, and the patient was placed on a 3-month periodontal maintenance interval.

DISCUSSION

Full mouth periodontal surgical and prosthodontic reconstruction on a PWS patient has not previously been reported in the literature. This case underscores the potential need for complex dental care in patients with this syndrome.

The Metabolic Efficacy of a Cannabidiolic Acid (CBDA) Derivative in Treating Diet- and Genetic-Induced Obesity

Obesity is a global medical problem; its common form is known as diet-induced obesity (DIO); however, there are several rare genetic disorders, such as Prader-Willi syndrome (PWS), that are also associated with obesity (genetic-induced obesity, GIO). The currently available therapeutics for treating DIO and GIO are very limited, and they result in only a partial improvement. Cannabidiolic acid (CBDA), a constituent of Cannabis sativa, gradually decarboxylates to cannabidiol (CBD). Whereas the anti-obesity properties of CBD have been reasonably identified, our knowledge of the pharmacology of CBDA is more limited due to its instability. To stabilize CBDA, a new derivative, CBDA-O-methyl ester (HU-580, EPM301), was synthesized. The therapeutic potential of EPM301 in appetite reduction, weight loss, and metabolic improvements in DIO and GIO was tested in vivo. EPM301 (40 mg/kg/d, i.p.) successfully resulted in weight loss, increased ambulation, as well as improved glycemic and lipid profiles in DIO mice. Additionally, EPM301 ameliorated DIO-induced hepatic dysfunction and steatosis. Importantly, EPM301 (20 and 40 mg/kg/d, i.p.) effectively reduced body weight and hyperphagia in a high-fat diet-fed Magel2^null mouse model for PWS. In addition, when given to standard-diet-fed Magel2^null mice as a preventive treatment, EPM301 completely inhibited weight gain and adiposity. Lastly, EPM301 increased the oxidation of different nutrients in each strain. All together, EPM301 ameliorated obesity and its metabolic abnormalities in both DIO and GIO. These results support the idea to further promote this synthetic CBDA derivative toward clinical evaluation in humans.

Prader–Willi Syndrome: Possibilities of Weight Gain Prevention and Treatment

Prader–Willi syndrome (PWS) is a complex genetic disorder which involves the endocrine and neurologic systems, metabolism, and behavior. The aim of this paper is to summarize current knowledge on dietary management and treatment of PWS and, in particular, to prevent excessive weight gain. Growth hormone (GH) therapy is the recommended standard treatment for PWS children, because it improves body composition (by changing the proportion of body fat and lean body mass specifically by increasing muscle mass and energy expenditure), linear growth, and in infants, it promotes psychomotor and IQ development. In early childhood, the predominant symptom is hyperphagia which can lead to early onset, severe obesity with different obesity-related comorbidities. There are several studies on anti-obesity medications (metformin, topiramate, liraglutide, setmelanotide). However, these are still limited, and no widely accepted consensus guideline exists concerning these drugs in children with PWS. Until there is a specific treatment for hyperphagia and weight gain, weight must be controlled with the help of diet and exercise. Below the age of one year, children with PWS have no desire to eat and will often fail to thrive, despite adequate calories. After the age of two years, weight begins to increase without a change in calorie intake. Appetite increases later, gradually, and becomes insatiable. Managing the progression of different nutritional phases (0–4) is really important and can delay the early onset of severe obesity. Multidisciplinary approaches are crucial in the diagnosis and lifelong follow-up, which will determine the quality of life of these patients.

Patients with Prader-Willi Syndrome (PWS) Underwent Bariatric Surgery Benefit more from High-Intensity Home Care

BACKGROUND

Long-term weight loss effect of bariatric surgeries for patients with Prader-Willi Syndrome (PWS) remains controversial since factors like postoperative home care intensity may impact the outcome. The aim of this study was to evaluate the role of home care intensity on long-term weight loss effect of bariatric surgery in patients with PWS.

METHODS

This was a prospective observational study on patients with PWS undergoing bariatric surgery and patients were enrolled from July 2015 to December 2016. Detailed information of patients' weight and behaviors was recorded by caregivers postoperatively. The intensities of home care applied to patients were classified into four categories (high, moderate, low, and very low) according to the records.

RESULTS

Six cases (3 males, 3 females) were enrolled in this study with LSG (n = 2), RYGB (n = 3), and LSG-DJB (n = 1) as their primary operation. The mean BMI of these participants was 46.78 ± 11.63 kg/m2, and the mean age was 17.66 ± 6.59 years. All patients had at least 5 years of follow-ups, and the %EWL were 51.57 ± 23.36%, 64.54 ± 18.97%, 35.34 ± 36.53%, 19.45 ± 41.78%, and - 4.74 ± 71.50% in the half, first, second, third, and fifth year after surgery respectively. Two patients with high-intensity home care achieved a %EWL of 70.57 ± 8.86% in the fifth year after surgery.

CONCLUSIONS

Overall long-term weight loss of bariatric surgery for patients with PWS was not found through the follow-ups. Two patients with high-intensity home care maintained weight loss at the fifth-year follow-up, suggesting a pivotal role of high-intensity home care in long-term outcomes of bariatric surgery in patients with PWS.

Sleep Disorders in Adults with Prader–Willi Syndrome: Review of the Literature and Clinical Recommendations Based on the Experience of the French Reference Centre

Prader–Willi syndrome (PWS) is a rare, genetic, multisymptomatic, neurodevelopmental disease commonly associated with sleep alterations, including sleep-disordered breathing and central disorders of hypersomnolence. Excessive daytime sleepiness represents the main manifestation that should be addressed by eliciting the detrimental effects on quality of life and neurocognitive function from the patients’ caregivers. Patients with PWS have impaired ventilatory control and altered pulmonary mechanics caused by hypotonia, respiratory muscle weakness, scoliosis and obesity. Consequently, respiratory abnormalities are frequent and, in most cases, severe, particularly during sleep. Adults with PWS frequently suffer from sleep apnoea syndrome, sleep hypoxemia and sleep hypoventilation. When excessive daytime sleepiness persists after adequate control of sleep-disordered breathing, a sleep study on ventilatory treatment, followed by an objective measurement of excessive daytime sleepiness, is recommended. These tests frequently identify central disorders of hypersomnolence, including narcolepsy, central hypersomnia or a borderline hypersomnolent phenotype. The use of wake-enhancing drugs (modafinil, pitolisant) is discussed in multidisciplinary expert centres for these kinds of cases to ensure the right balance between the benefits on quality of life and the risk of psychological and cardiovascular side effects.

Health Problems in Individuals With PWS Are Associated With Lower Quality of Life for Their Parents: A Snapshot in the Brazilian Population

Prader-Willi syndrome (PWS) is a complex genetic disorder requiring interdisciplinary team monitoring and intensive care by parents. So far there is little information on people with PWS in Brazil. Our aim was to describe health problems and treatments used by people with PWS in Brazil and their relationship to their parents' quality of life. Parents answered questionnaires about their child's medical and exercise history, behavior problems, sociodemographic characteristics, and their own quality of life. Results: The responses of the participants showed similar health problems as in other countries. Anxiety and tantrums were the behavioral problems most commonly cited by parents. Parents of people with PWS had lower scores in respect of quality of life than the Brazilian population. Behavioral problems in individuals with PWS were negatively associated with their parents' quality of life. Behavioral and medical conditions in the children were associated with reduced quality of life in the parents. We conclude that heath care should not only be directed toward those with PWS, but also their parents.

Hashimoto's Thyroiditis and Graves' Disease in Genetic Syndromes in Pediatric Age

Autoimmune thyroid diseases (AITDs), including Hashimoto’s thyroiditis (HT) and Graves’ disease (GD), are the most common cause of acquired thyroid disorder during childhood and adolescence. Our purpose was to assess the main features of AITDs when they occur in association with genetic syndromes. We conducted a systematic review of the literature, covering the last 20 years, through MEDLINE via PubMed and EMBASE databases, in order to identify studies focused on the relation between AITDs and genetic syndromes in children and adolescents. From the 1654 references initially identified, 90 articles were selected for our final evaluation. Turner syndrome, Down syndrome, Klinefelter syndrome, neurofibromatosis type 1, Noonan syndrome, 22q11.2 deletion syndrome, Prader–Willi syndrome, Williams syndrome and 18q deletion syndrome were evaluated. Our analysis confirmed that AITDs show peculiar phenotypic patterns when they occur in association with some genetic disorders, especially chromosomopathies. To improve clinical practice and healthcare in children and adolescents with genetic syndromes, an accurate screening and monitoring of thyroid function and autoimmunity should be performed. Furthermore, maintaining adequate thyroid hormone levels is important to avoid aggravating growth and cognitive deficits that are not infrequently present in the syndromes analyzed.

Case Report: Clinical Analysis of Seven Neonates With Prader-Willi Syndrome and Review of the Literature

Objective: The clinical symptoms of neonatal Prader-Willi syndrome (PWS) are not typical and are easy to miss. The aim of the study was to investigate the clinical features and genetic characteristics of seven cases of neonatal PWS from northern China, and to improve the understanding of PWS in neonates. Methods: We retrospectively analyzed seven infants diagnosed by methylation specific multiplex ligation probe amplification technology (MS-MLPA) in the Neonatology Unit of Shengjing Hospital of China Medical University from September 2016 to July 2020. Results: All seven cases involved full term or nearly full-term infants born to mothers without a history of abnormal pregnancy or delivery. Difficulty in feeding occurred immediately after birth in infants with decreased hypotonia. Five patients had characteristic craniofacial morphology, such as a prominent forehead, narrow face, almond-shaped eyes, small mouth, and downturned mouth. Further, three of the seven infants had patent ductus arteriosus (PDA). In addition, three neonates had hyperammonemia, hypoglycemia, and idiopathic edema, respectively. PWS could be effectively diagnosed and genotyped by MS-MLPA. Conclusion: Neonates with PWS have hypotonia and feeding difficulty. Characteristic facial features and genital hypoplasia are common in neonatal PWS. Infants with PWS may be predisposed to PDA, hypoglycemia, hyperammonemia, and edema.

Genetic Determinants of Childhood Obesity

Obesity represents a major health burden to both developed and developing countries. Furthermore, the incidence of obesity is increasing in children. Obesity contributes substantially to mortality in the United States by increasing the risk for type 2 diabetes, cardiovascular-related diseases, and other comorbidities. Despite environmental changes over past decades, including increases in high-calorie foods and sedentary lifestyles, there is very clear evidence of a genetic predisposition to obesity risk. Childhood obesity cases can be categorized in one of two ways: syndromic or non-syndromic. Syndromic obesity includes disorders such as Prader-Willi syndrome, Bardet-Biedl syndrome, and Alström syndrome. Non-syndromic cases of obesity can be further separated into rarer instances of monogenic obesity and much more common forms of polygenic obesity. The advent of genome-wide association studies (GWAS) and next-generation sequencing has driven significant advances in our understanding of the genetic contribution to childhood obesity. Many rare and common genetic variants have been shown to contribute to the heritability in obesity, although the molecular mechanisms underlying most of these variants remain unclear. An important caveat of GWAS efforts is that they do not strictly represent gene target discoveries, rather simply the uncovering of robust genetic signals. One clear example of this is with progress in understanding the key obesity signal harbored within an intronic region of the FTO gene. It has been shown that the non-coding region in which the variant actually resides in fact influences the expression of genes distal to FTO instead, specifically IRX3 and IRX5. Such discoveries suggest that associated non-coding variants can be embedded within or next to one gene, but commonly influence the expression of other, more distal effector genes. Advances in genetics and genomics are therefore contributing to a deeper understanding of childhood obesity, allowing for development of clinical tools and therapeutic agents.

Three scenarios illustrating ethical concerns when considering bariatric surgery in obese adolescents with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is one of the 25 syndromic forms of obesity, in which patients present-in addition to different degrees of obesity-intellectual disability, endocrine disturbs, hyperphagia and/or other signs of hypothalamic dysfunction. In front of a severe/extreme obesity and the failure of non-invasive treatments, bariatric surgery is proposed as a therapeutic option. The complexity of the clinical condition, which could affect the long-term effects of bariatric surgery, and the frequent association with a mild to severe intellectual disability raise some ethical concerns in the treatment of obese PWS adolescents. This article analyses these issues referring to the principles of healthcare ethics: beneficence/non-maleficence (proportionality of treatments; minimisation of risks); respect of autonomy; justice. Based on these principles, three hypothetical scenarios are defined: (1) obese PWS adolescent, capable of making an autonomous decision; (2) obese PWS adolescent with a severe intellectual disability, whose parents agree with bariatric surgery; (3) obese PWS adolescent with a life-threatening condition and a severe intellectual disability, whose parents do not agree with bariatric surgery. The currently available evidence on efficacy and safety of bariatric surgery in PWS adolescents with extreme or severe obesity and the lack of adequate long-term follow-up suggests great caution even in a very life-threatening condition. Clinicians must always obtain a full IQ assessment of patients by psychologists. A multidisciplinary team is needed to analyse the clinical, psychological, social and ethical aspects and organise support for patient and parents, involving also the hospital ethical committee or, if necessary, legal authorities.

Growth hormone treatment in Prader-Willi syndrome patients: systematic review and meta-analysis

BACKGROUND

Growth hormone (GH) treatment is currently recommended in Prader-Willi syndrome (PWS) patients.

OBJECTIVES

To evaluate the impact (efficacy and safety) of the use of recombinant human GH (rhGH) as a treatment for PWS.

METHOD

We performed a systematic review and, where possible, meta-analysis for the following outcomes: growth, body mass index, body composition, cognitive function, quality of life, head circumference, motor development/strength, behaviour and adverse effects. We included all PWS patients, with all types of genetic defects and with or without GH deficiency, who participated in rhGH studies performed in infancy, childhood and adolescence, that were either randomised controlled trials (RCTs) (double-blinded or not) or non-randomised controlled trials (NRCTs) (cohort and before and after studies). The databases used were MEDLINE, Embase and Cochrane Central.

RESULTS

In 16 RCTs and 20 NRCTs selected, the treated group had an improvement in height (1.67 SD scores (SDS); 1.54 to 1.81); body mass index z-scores (-0.67 SDS; -0.87 to -0.47) and fat mass proportion (-6.5% SDS; -8.46 to -4.54) compared with the control group. Data about cognition could not be aggregated. Conclusion Based on high quality evidence, rhGH treatment favoured an improvement of stature, body composition and body mass index, modifying the disease's natural history; rhGH treatment may also be implicated in improved cognition and motor development in PWS patients at a young age.

ETHICS AND DISSEMINATION

The current review was approved by the ethical committee of our institution. The results will be disseminated through conference presentations and publications in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42019140295.

Prader- Willi syndrome: An uptodate on endocrine and metabolic complications

Prader-Willi syndrome (PWS) is a genetic disorder characterized by short stature, low lean body mass, muscular hypotonia, mental retardation, behavioral abnormalities, dysmorphic features, and excessive appetite with progressive obesity. It is caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13. This genetic disorder has an estimated prevalence that ranges between 1/10,000-1/30,000. Hypothalamic dysfunction is a common finding in PWS and it has been implicated in several manifestations of this syndrome such as hyperphagia, temperature instability, high pain threshold, sleep disordered breathing, and multiple endocrine abnormalities. These include growth hormone deficiency, central adrenal insufficiency, hypogonadism, hypothyroidism, and obesity often complicated by type 2 diabetes. The aim of this manuscript is to overview the current literature on metabolic and endocrine complications of PWS, focusing on human studies and providing insights on the physio pathological mechanisms. A careful management of metabolic and endocrine complications can contribute to improve quality of life, prevent complications, and prolong life expectancy of PW patients.