Mental and motor development before and during growth hormone treatment in infants and toddlers with Prader-Willi syndrome

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.

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.

Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

Background

Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.

Methods

We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.

Results

We included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR (p=0.027, p=0.019, p<0.001, p<0.001, p=0.011 and respectively).

Conclusion

Upon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.

Schaaf-Yang Syndrome: Clinical Phenotype and Effects of 4 years of Growth Hormone Treatment

INTRODUCTION

Schaaf-Yang syndrome (SYS) is a rare neurodevelopmental disorder caused by truncating mutations of the MAGEL2 gene, located in the Prader-Willi syndrome (PWS) region. PWS and SYS have phenotypic overlap. Patients with SYS are often treated with growth hormone (GH), but evidence for the effectiveness of the treatment in patients with SYS is limited.

METHODS

This study describes 7 children with SYS. We studied their phenotype, genotype, and the effect of GH treatment on height and body mass index (BMI) during 4 years and on body composition during 1 year.

RESULTS

All patients had a normal birth weight. Most patients had hypotonia and feeding difficulties after birth (86%). Full-scale IQ ranged from <50 to 92. All patients above the age of 2 years had psycho-behavioral problems. There were no apparent correlations between the phenotype and the location of the defect in the MAGEL2 gene. Mean (95% CI) height SDS increased significantly from -1.74 (-3.55; 0.07) at start to -0.05 (-1.87; 1.77) after 4 years of GH treatment. Mean (95% CI) BMI SDS decreased significantly from 2.01 (1.02; 3.00) to 1.22 (0.18; 2.26) after 6 months and remained the same during the rest of the follow-up. Fat mass percentage SDS decreased and lean body mass did not change during 1 year of treatment in 3 patients.

CONCLUSION

Patients presented with a phenotype of hypotonia, respiratory insufficiency, and feeding difficulties after birth, endocrine disorders, intellectual disability, and behavioral problems. Treatment with GH significantly improved height SDS and BMI over the course of 4 years.

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.

GH treatment in pediatric Down syndrome: a systematic review and mini meta-analysis

Objective

To analyze and determine the safety and efficacy of growth hormone (GH) treatment in Down syndrome (DS) pediatric patients and to weigh ethical aspects involved.

Design

Systematic review and mini meta-analysis of the literature.

Methods

A search was performed in PubMed, Embase, Scopus, and PsycINFO through August 2022. Eligible studies included those who answered at least one of the following two questions: 1) What is the effect of growth hormone treatment in children with Down syndrome? 2) What are the ethical arguments in favor and against growth hormone treatment for children with Down syndrome? Multiple reviewers independently screened each article for eligibility.

Results

In total sixteen reports detailed medical effects of GH treatment in pediatric DS patients and eight studies dealt with ethical aspects of GH treatment. Treatment with GH resulted in significantly higher growth velocity in patients with DS. The ethical complexity is great but does not present insurmountable difficulties to the therapeutic option.

Conclusions

As GH treatment is safe and effective for short-term height growth, GH therapy should be considered in long-term treatment of DS children.

Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms

BACKGROUND

Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the OCRL gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy.

METHODS

This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association. Frequency of non-ocular clinical feature(s) of LS and their age of onset was summarised. An LS-specific therapy effectiveness scale was used to assess the response to the administered treatment. Expression of OCRL and relevant neuropeptides was measured in postmortem human brain by qPCR. Gene expression in the mouse brain was determined by reanalysis of publicly available bulk and single cell RNA sequencing.

RESULTS

A total of 137 individuals (1 female, 89.1% white, median age 14 years (range 0.8-56)) were included in the study. Short stature (height <3rd percentile) was noted in 81% (n=111) individuals, and 15% (n=20) received growth hormone therapy. Undescended testis was reported in 47% (n=64), and median age of onset of puberty was 15 years. Additional features were dental problems (n=77, 56%), bone fractures (n=63, 46%), hypophosphataemia (n=60, 44%), developmental delay and behavioural issues. OCRL is expressed in human and mouse hypothalami, and in hypothalamic cell clusters expressing Ghrh, Sst, Oxt, Pomc and pituitary cells expressing Gh and Prl.

CONCLUSIONS

There is a wide spectrum of the clinical phenotype of LS. Some of the features may be partly driven by the loss of function of OCRL in the hypothalamus and the pituitary.

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.

Relationship between growth and intelligence quotient in children with Down syndrome

BACKGROUND

The relationship between intelligence quotient (IQ) and somatic development, especially growth, has been demonstrated in various groups of children. Down syndrome (DS) is characterized by short stature, overweight, and cognitive impairment. The objective of our work was to assess whether anthropometric measurements [weight, height, body mass index (BMI)] of children with DS correlate with their IQ. The results of the study may be valuable for this population in the light of increasing access to growth hormone therapy (GHT) in various genetic syndromes with short stature. Based on previous studies on children, we hypothesized that a link exists between IQ and somatic development, particularly growth.

METHODS

This cross-sectional study included 40 children with DS, who were aged 9-18 years. The studied population was selected from the registry of the Genetic Clinic at the University Clinical Center in Gdańsk (Poland). Anthropometric measurements (weight and height) were taken for all the children, and their BMI was determined using these data. The obtained results were plotted on charts for children with DS. The IQ of the children was assessed using the Stanford Binet Intelligence Scale, Fifth Edition. The correlations between IQ and anthropometric data were analyzed using univariate correlation and multiple regression analyses.

RESULTS

The results showed that full-scale, verbal, and nonverbal IQ correlated with height percentile (P=0.03, P=0.02, and P=0.04, respectively), but not with weight (P=0.26, P=0.19, and P=0.61, respectively) or BMI (P=0.6, P=0.5, and P=0.72, respectively). In multiple linear regression analysis, height percentile remained as an independent determinant of the IQ results after adjusting for birth weight, hypothyroidism with L-thyroxine replacement therapy, and congenital cardiac defect (β=0.48, P=0.018).

CONCLUSIONS

The results of our study suggest an association between growth and IQ in children with DS. The presented findings may be valuable for improving access to GHT for populations with genetic syndromes characterized by short stature. However, these should be confirmed by further research with a longitudinal sample of children with DS.

Inter- and intra-observer reliability of the "Assessment of Motor Repertoire- 3 to 5 Months" based on video recordings of infants with Prader-Willi syndrome

Background

The “Assessment of Motor Repertoire—3 to 5 Months”, which is a part of Prechtl's General Movements Assessment (GMA), has been gradually applied to infants with genetic metabolic disorders. However, there have been no studies on the application of the GMA for infants with Prader-Willi syndrome (PWS).

Aims

The purpose of this study was to determine the inter- and intra-observer reliability of the assessment tool in a population of infants with PWS.

Study design

This was a reliability and agreement study.

Subjects

This was a cross-sectional study with15 infants with PWS born at an average gestational age of 38 weeks.

Outcome measures

Standardized video recordings of 15 infants with PWS (corrected ages of 3 to 5 months) were independently assessed by three observers. Kappa and ICC statistics were applied in inter- and intra- observer reliability analyses.

Results

The overall reliability ICC values of the “Motor Optimality Score” (MOS) ranged from 0.84 to 0.98, and the pairwise agreement ranged between 0.86 and 0.95 for inter- observe reliability. In addition, ICC values for the MOS ranged between 0.95 and 0.98 for tester agreement in intra-observer reliability.

Complete agreement reliability (100%) was achieved in the subcategories of “Fidgety Movements” and “Movement Character” for the inter- and intra-observer reliability. Moderate to high inter- and intra-observer reliability were found in the subcategories of “Repertoire of Co-Existent Other Movements”, “Quality of Other Movements” and “Posture”, with kappa values ranging between 0.63 and 1.00.

Conclusion

There were high levels of inter-and intra-observer agreement in the “Assessment of Motor Repertoire—3 to 5 Months” for infants with PWS. It is possible to carry out standardized quantitative assessments of the motor performance of infants with PWS.

Free Insulin-like Growth Factor (IGF)-I in Children with PWS

In children with Prader−Willi syndrome (PWS), the standard growth hormone (GH) dose often results in high immunoreactive IGF-I levels. These high immunoreactive IGF-I levels lead to concern because their long-term effects are unknown. As a result, clinicians have to lower the GH dose, which worsens body composition and quality of life. As clinical features do not seem to correspond to immunoreactive IGF-I values, it is questionable whether immunoreactive IGF-I is a suitable marker for GH dosing, or whether another parameter better reflects IGF-I bioavailability and bioactivity. We, therefore, investigate serum immunoreactive IGF-I, free IGF-I and IGFBP-3 levels in 70 GH-treated children with PWS. Our study showed that, although immunoreactive IGF-I levels were high (>2 SDS) in the vast majority of prepubertal and pubertal children, free IGF-I SDS levels were <0 SDS in most and <1 SDS in all. Free IGF-I correlated with the immunoreactive IGF-I, IGFBP-3 and IGF-I/IGFBP-3 ratio. We conclude that there is a major discrepancy between immunoreactive and free IGF-I levels. While in the majority of GH-treated children with PWS, immunoreactive IGF-I levels were high, free IGF-I levels were <0 SDS in most. Our data appear to be very reassuring and suggest that free IGF-I levels should also be taken into consideration when the immunoreactive IGF-I levels are >2 SDS in GH-treated children with PWS.

Prenatal and Neonatal Characteristics of Children with Prader-Willi Syndrome

Objective: Prader-Willi syndrome (PWS) is a rare genetic syndrome with a wide spectrum of clinical features in early life. Late diagnoses are still present. We characterized the perinatal and neonatal features of PWS, compared them with those of healthy newborns and assessed the prenatal and neonatal differences between the genetic subtypes. Design: A cohort study in children with PWS. The prevalence of variables was compared with healthy infants (PLUTO cohort) and to population statistics from literature. Patients: 244 infants with PWS and 365 healthy infants. Measurements: Data on prenatal and neonatal variables in both cohorts. Population statistics were collected through an extensive literature search. Results: A higher prevalence of maternal age >35 years was found in PWS compared to healthy infants and population statistics, and the highest maternal age was found in the mUPD group. Higher prevalence of polyhydramnios, caesarean section, labour induction and breech presentation, and lower birth weight SDS was found in PWS compared to healthy infants. High prevalences of decreased fetal movements (78.5%), hypotonia (100%), cryptorchism (95.9%) and poor sucking/tube feeding (93.9%) were found in PWS. Conclusions: This study presents an overview of prenatal and neonatal variables in infants with PWS compared to healthy infants. Our findings may increase clinical awareness of the early perinatal signs of PWS by obstetricians, neonatologists and all those involved in infant care, enabling early diagnosis and start of multidisciplinary treatment.

Sleep Disorders in Children with Prader Willi Syndrome: Current Perspectives

Children with Prader-Willi syndrome (PWS) face a multitude of potential health challenges including life-threatening obesity, endocrinopathies, behavioral and emotional dysregulation, developmental delays, and sleep disorders. In the current perspective piece, we provide a focused review of the condition's etiology and clinical findings, as well as a more in-depth discussion of sleep disorders frequently associated with PWS. In particular, we highlight and discuss difficult clinical scenarios frequently encountered by the pediatric sleep physician caring for this patient population, including diagnosis and treatment of complex sleep-related breathing disorders, considerations for sleep apnea surgery, the interplay between growth hormone and sleep apnea, diagnostic challenges in hypersomnia/narcolepsy, and current and emerging therapies for hypersomnia/narcolepsy. Overall, although there are many areas that need further research, sleep disorders remain a fruitful target for improving quality of life of children with PWS and their families.

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.

Obesity in Prader-Willi syndrome: physiopathological mechanisms, nutritional and pharmacological approaches

Prader-Willi syndrome (PWS) is a genetic disorder caused by the lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. The three main genetic subtypes are represented by paternal 15q11-q13 deletion, maternal uniparental disomy 15, and imprinting defect. Clinical picture of PWS changes across life stages. The main clinical characteristics are represented by short stature, developmental delay, cognitive disability and behavioral diseases. Hypotonia and poor suck resulting in failure to thrive are typical of infancy. As the subjects with PWS age, clinical manifestations such as hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency due to hypothalamic dysfunction occur. Obesity and its complications are the most common causes of morbidity and mortality in PWS. Several mechanisms for the aetiology of obesity in PWS have been hypothesized, which include aberration in hypothalamic pathways of satiety control resulting in hyperphagia, disruption in hormones regulating appetite and satiety and reduced energy expenditure. However, despite the advancement in the research field of the genetic basis of obesity in PWS, there are contradictory data on the management. Although it is mandatory to adopt obesity strategy prevention from infancy, there is promising evidence regarding the management of obesity in adulthood with current obesity drugs along with lifestyle interventions, although the data are limited. Therefore, the current manuscript provides a review of the current evidence on obesity and PWS, covering physiopathological aspects, obesity-related complications and conservative management.

Effects of Childhood Multidisciplinary Care and Growth Hormone Treatment on Health Problems in Adults with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex hypothalamic disorder. Features of PWS include hyperphagia, hypotonia, intellectual disability, and pituitary hormone deficiencies. The combination of growth hormone treatment and multidisciplinary care (GHMDc) has greatly improved the health of children with PWS. Little is known about the effects of childhood GHMDc on health outcomes in adulthood. We retrospectively collected clinical data of 109 adults with PWS. Thirty-nine had received GHMDc during childhood and adolescence (GHMDc+ group) and sixty-three had never received growth hormone treatment (GHt) nor multidisciplinary care (GHMDc− group). Our systematic screening revealed fewer undetected health problems in the GHMDc+ group (10%) than in the GHMDc− group (84%). All health problems revealed in the GHMDc+ group had developed between the last visit to the paediatric and the first visit to the adult clinic and/or did not require treatment. Mean BMI and the prevalence of diabetes mellitus type 2 were significantly lower in the GHMDc+ group compared to the GHMDc− group. As all patients who received GHt were treated in a multidisciplinary setting, it is unknown which effects are the result of GHt and which are the result of multidisciplinary care. However, our data clearly show that the combination of both has beneficial effects. Therefore, we recommend continuing GHMDc after patients with PWS have reached adult age.

Prader-Willi Syndrome: Molecular Mechanism and Epigenetic Therapy

Prader-Willi syndrome (PWS) is an imprinted neurodevelopmental disease characterized by cognitive impairments, developmental delay, hyperphagia, obesity, and sleep abnormalities. It is caused by a lack of expression of the paternally active genes in the PWS imprinting center on chromosome 15 (15q11.2-q13). Owing to the imprinted gene regulation, the same genes in the maternal chromosome, 15q11-q13, are intact in structure but repressed at the transcriptional level because of the epigenetic mechanism. The specific molecular defect underlying PWS provides an opportunity to explore epigenetic therapy to reactivate the expression of repressed PWS genes inherited from the maternal chromosome. The purpose of this review is to summarize the main advances in the molecular study of PWS and discuss current and future perspectives on the development of CRISPR/Cas9- mediated epigenome editing in the epigenetic therapy of PWS. Twelve studies on the molecular mechanism or epigenetic therapy of PWS were included in the review. Although our understanding of the molecular basis of PWS has changed fundamentally, there has been a little progress in the epigenetic therapy of PWS that targets its underlying genetic defects.

A retrospective analysis of growth hormone therapy in children with Schaaf-Yang syndrome

Short stature is a common phenotype in children with Schaaf-Yang syndrome (SYS). Prader-Willi syndrome (PWS) and SYS share several phenotypic features including short stature, muscular hypotonia and developmental delay/intellectual disability. Evidence exists that similar to PWS, growth hormone (GH) deficiency may also be a feature of SYS. Recombinant human GH (rhGH) therapy has been approved for PWS, but the effects of rhGH therapy in individuals with SYS have not yet been documented. This retrospective, questionnaire-based study analyzes the prevalence of rhGH therapy in children with SYS, the effects of rhGH therapy on anthropometric measures, and parental perception of the treatment. Twenty-six individuals with SYS were sent a clinical questionnaire and a request for growth charts. We found a significant increase in height z-score (p* = 0.04) as well as a significant decrease in body mass index 6 months after rhGH therapy initiation (p* = 0.04). Furthermore, height z-scores of the treated group (mean z-score = -1.00) were significantly higher than those of the untreated group (mean z-score = -3.36, p = 0.01) at time of enrollment. All parents reported an increase in muscle strength and endurance, and several families noted beneficial effects such as improved cognition and motor development.

Oxytocin in young children with Prader-Willi syndrome: Results of a randomized, double-blind, placebo-controlled, crossover trial investigating 3 months of oxytocin

CONTEXT

Prader-Willi syndrome (PWS) is characterized by hypothalamic dysfunction, hyperphagia and a typical behavioural phenotype, with characteristics of autism spectrum disorder (ASD) like stubbornness, temper tantrums and compulsivity. It has been suggested that the oxytocin system in patients with PWS is dysfunctional. In ASD, intranasal oxytocin treatment has favourable effects on behaviour.

OBJECTIVE

To evaluate the effects of 3 months of twice daily intranasal oxytocin (dose range 16-40 IU/day), compared to placebo, on behaviour and hyperphagia in children with PWS.

DESIGN

Randomized, double-blind, placebo-controlled, crossover study in the Dutch PWS Reference Center.

PATIENTS

Twenty-six children with PWS aged 3-11 years.

MAIN OUTCOME MEASURES

(Change in) behaviour and hyperphagia measured by Oxytocin Questionnaire and Dykens hyperphagia questionnaire.

RESULTS

In the total group, no significant effects of oxytocin on social behaviour or hyperphagia were found. However, in boys, the Oxytocin Questionnaire scores improved significantly during oxytocin treatment, compared to a deterioration during placebo (4.5 (-0.8 to 15.3) vs. -4.0 (-11.3 to 0.8), P = .025). The Dykens hyperphagia questionnaire scores remained similar during oxytocin treatment, while there was a deterioration during placebo (0.0 (-0.8 to 4.3) vs. -3.5 (-6.0 to 0.0), P = .046). Patients with a deletion had significant improvements in both questionnaire scores during oxytocin treatment, but deteriorations during placebo. Oxytocin treatment was well tolerated, and there were no serious adverse events.

CONCLUSIONS

Intranasal oxytocin treatment has positive effects on social and eating behaviour in 3-11 years aged boys with PWS and in children with a deletion without safety concerns. Intranasal oxytocin in children with PWS might be considered, but individual effects should be carefully evaluated and treatment discontinued if no effects are found.

Effects of growth hormone on cognitive, motor, and behavioral development in Prader-Willi syndrome children: a meta-analysis of randomized controlled trials

PURPOSE

The benefits of growth hormone (GH) therapy in Prader-Willi syndrome (PWS) children are well established, but there is still considerable controversy regarding whether GH treatment can improve cognitive, motor, and behavioral development in PWS children. The objectives of this meta-analysis were to quantitatively evaluate the effects of GH on cognitive, motor function, and behavioral development in PWS children.

METHODS

Randomized controlled trials (RCTs) examining the effects of GH on cognitive, motor, and behavioral development in PWS children were identified by searching the MEDLINE, EMBASE, and Cochrane Library databases. Intervention effects were represented by Hedges'g and pooled to calculate effect sizes using a random-effects model.

RESULTS

Ten relevant studies comprising data from 302 participants were finally included. We observed no significant difference in cognitive performance between the GH treatment group and the control group (p = 0.197). GH treatment was shown to remarkably improve motor development in PWS children compared with the control treatment (p < 0.001), with moderate positive treatment effects (Hedges'g [95% CI] = 0.71 [0.38, 1.03]). There were no significant differences between the GH group and the control group based on objective assessments of behavioral development (p = 0.53).

CONCLUSIONS

The meta-analysis suggested that GH treatment had a significantly positive effect on motor development, with moderate treatment effects in PWS children; however, there was no evidence of effects on cognitive or behavioral development.

Genetic Subtype-Phenotype Analysis of Growth Hormone Treatment on Psychiatric Behavior in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex multisystemic condition caused by a lack of paternal expression of imprinted genes from the 15q11.2-q13 region. Limited literature exists on the association between molecular classes, growth hormone use, and the prevalence of psychiatric phenotypes in PWS. In this study, we analyzed nine psychiatric phenotypes (depressed mood, anxiety, skin picking, nail picking, compulsive counting, compulsive ordering, plays with strings, visual hallucinations, and delusions) recognized in PWS and investigated associations with growth hormone treatment (GHT), deletions (DEL) and uniparental disomy (UPD) in a cohort of 172 individuals with PWS who met the criteria for analysis. Associations were explored using Pearson chi-square tests and univariable and multivariable logistic regression analyses to control for confounding exposures. This observational study of the largest dataset of patients with PWS to date suggested the following genetic subtype and phenotype correlations in psychiatric behaviors: (1) skin picking was more frequent in those with DEL vs. UPD; (2) anxiety was more common in those with UPD vs. DEL; and (3) an increased frequency of anxiety was noted in the UPD group treated with GHT compared to the DEL group. No other significant associations were found between the genetic subtype or GHT including for depressed mood, nail picking, compulsive counting, compulsive ordering, playing with strings, and visual hallucinations. Further studies will be required before any conclusions can be reached.

Three years of growth hormone treatment in young adults with Prader-Willi Syndrome previously treated with growth hormone in childhood: Effects on glucose homeostasis and metabolic syndrome

CONTEXT

Growth hormone (GH) has been approved for children with Prader-Willi syndrome (PWS) and significantly improves body composition in adults with PWS. Adults with PWS are predisposed to develop impaired glucose tolerance (IGT) and diabetes mellitus type 2 (DMT2). Continuation of GH maintains body composition, but GH is known to induce insulin resistance, which might affect glucose homeostasis. Studies on long-term effects of GH treatment in adults are very limited.

OBJECTIVE

To investigate effects of 3 years of GH treatment on glucose homeostasis and prevalence of metabolic syndrome (MS) in adults with PWS.

DESIGN

Open-label, prospective study.

PATIENTS

43 young adults with PWS.

SETTING

Dutch PWS Reference Center.

MAIN OUTCOME MEASURES

Glucose and insulin during oral glucose tolerance test.

RESULTS

Estimated mean (95% CI) fasting glucose and insulin levels remained stable during 3 years of GH treatment. Glucose being 4.6 (4.4-4.8) mmol/l at start and 4.7 (4.6-4.9) mmol/l after 3 years (P = .07); insulin being 59.5 (45.2-75.8) pmol/l and 56.7 (45.2-69.6) pmol/l resp. (P = .72). Sex, ethnicity and fat mass percentage were significantly associated with fasting glucose levels, while IGF-I or GH-dose were not. Blood pressure, lipids and prevalence of MS remained stable during 3 years of GH. IGT prevalence was variable over time, six patients had IGT at start and eleven after 3 years of GH. One patient developed DMT2. However, prevalence of IGT or DMT2 was not significantly higher after 3 years than at study start.

CONCLUSIONS

Three years of GH treatment in adults with PWS does not impair glucose homeostasis and does not lead to an increased prevalence of DMT2.

Measures of nocturnal oxyhemoglobin desaturation in children with neuromuscular disease or Prader-Willi syndrome

OBJECTIVES

Evidence for nocturnal oximetry interpretation in patients with abnormal neuromuscular function is limited. We aimed to compare children with neuromuscular disease (NMD) or Prader-Willi syndrome (PWS) to otherwise healthy subjects with obstructive sleep-disordered breathing (SDB) or without respiratory disorder (controls) regarding nocturnal oximetry parameters.

METHODS

We analyzed recordings from children with: (a) NMD; (b) PWS; (c) snoring and adenotonsillar hypertrophy and/or obesity (SDB); and (d) controls. Outcomes included: (a) basal SpO₂ ; (b) proportions of subjects with McGill oximetry score (MOS) >1 (clusters of desaturations); and (c) desaturation index (SpO₂ drops ≥3%/h-ODI3).

RESULTS

Data of 12 subjects with NMD (median age, 5.2 years; IQR, 2.7, 8.2), 14 children with PWS (5 years; 2.3, 6.9), 21 children with SDB (5.8 years; 4.6, 9.6), and 20 controls (6.2 years; 5.4, 11.2) were analyzed. Children with NMD, PWS, and SDB had lower basal SpO₂ than controls (95.6% [94.5%, 96.9%], 96.2% [95.1%, 97.4%], 96.1% [95.8%, 97.5%] vs 97.8% [97.2%, 97.9%], respectively; (P < .01). NMD and PWS showed the greatest negative effect on basal SpO₂ (P < .05). Children with SDB or PWS had a higher risk of MOS >1 than patients with NMD (OR, 25.9 [95% CI, 3.4-200.4] and 9.5 [1.5-62.6]). NMD, PWS, and SDB were similar regarding ODI3, which was elevated compared to ODI3 in controls (P < .05). Frequent desaturations predominated in NMD, while periods of sustained desaturation were noted in NMD and PWS.

CONCLUSION

PWS and NMD have a negative effect on basal SpO₂ , while clusters of desaturations are prevalent in patients with PWS or obstructive SDB.

Three years of growth hormone treatment in young adults with Prader-Willi syndrome: sustained positive effects on body composition

BACKGROUND

In children with Prader-Willi syndrome (PWS), the benefits of growth hormone treatment are well established. Several one-year studies have shown that growth hormone is also beneficial for adults with PWS, improving body composition. However, little is known about the longer-term effects. This study investigated the effects on body composition in adult patients with PWS during 3 years of growth hormone therapy in a dose of 0.33 mg/m²/day.

METHODS

Open-label, prospective study in 43 young adults with PWS with a median (IQR) age of 19.0 (17.5 to 20.7) years. Fat mass percentage SDS and lean body mass SDS were measured annually by DXA.

RESULTS

Estimated mean (95% CI) fat mass percentage SDS decreased during the three-year study from 2.1 (1.9 to 2.3) SDS at start to 1.9 (1.8 to 2.1) SDS, p = 0.012, while lean body mass SDS remained stable at - 2.1 (- 2.4 to - 1.8) SDS at start to - 1.9 (- 2.3 to - 1.6) after 3 years, p = 0.15. Fasting glucose and insulin remained similar during the three-year study, glucose being 4.6 (4.4 to 4.8) mmol/l at start and 4.6 (4.5 to 4.7) mmol/l after 3 years of growth hormone, p = 0.93 and insulin being 59.5 (42.2 to 81.5) pmol/l and 55.0 (42.4 to 69.2) pmol/l, resp., p = 0.54. There were no growth hormone-related adverse events during the study.

CONCLUSIONS

Three years of growth hormone treatment in young adults with PWS maintains the positive effects on body composition attained during childhood. Thus, adults with PWS benefit from longer-term growth hormone treatment.

TRIAL REGISTRATION

EudraCT, EudraCT number 2011-001313-14. Registered 17 October 2012.

Evidence for Accelerated Biological Aging in Young Adults with Prader-Willi Syndrome

OBJECTIVE

Adults with Prader-Willi syndrome (PWS) are at increased risk of developing age-associated diseases early in life and, like in premature aging syndromes, aging might be accelerated. We investigated leukocyte telomere length (LTL), a marker of biological age, in young adults with PWS and compared LTL to healthy young adults of similar age. As all young adults with PWS were treated with growth hormone (GH), we also compared LTL in PWS subjects to GH-treated young adults born short for gestational age (SGA).

DESIGN

Cross-sectional study in age-matched young adults; 47 with PWS, 135 healthy, and 75 born SGA.

MEASUREMENTS

LTL measured by quantitative polymerase chain reaction, expressed as telomere/single copy gene ratio.

RESULTS

Median (interquartile range) LTL was 2.6 (2.4-2.8) at a median (interquartile range) age of 19.2 (17.7-21.3) years in PWS, 3.1 (2.9-3.5) in healthy young adults and 3.1 (2.8-3.4) in the SGA group. Median LTL in PWS was significantly lower compared to both control groups (P < .01). In PWS, a lower LTL tended to be associated with a lower total IQ (r = 0.35, P = .08). There was no association between LTL and duration of GH treatment, cumulative GH dose, or several risk factors for type 2 diabetes mellitus or cardiovascular disease.

CONCLUSIONS

Young adults with PWS have significantly shorter median LTL compared to age-matched healthy young adults and GH-treated young adults born SGA. The shorter telomeres might play a role in the premature aging in PWS, independent of GH. Longitudinal research is needed to determine the influence of LTL on aging in PWS.

Prader-Willi syndrome: endocrine manifestations and management

Prader-Willi syndrome (PWS) is a genetic disorder caused by the absence of gene expression in the 15q11.2-q13 paternal chromosome. Patients with PWS develop hypothalamic dysfunction that can lead to various endocrine changes such as: obesity, growth hormone deficiency, hypogonadism, hypothyroidism, adrenal insufficiency and low bone mineral density. In addition, individuals with PWS have increased risk of developing type 2 diabetes mellitus. This review summarizes and updates the current knowledge about the prevention, diagnosis and treatment of endocrine manifestations associated with Prader Willi syndrome, especially diagnosis of growth hormone deficiency, management and monitoring of adverse effects; diagnosis of central adrenal insufficiency and management in stressful situations; screening for central hypothyroidism; research and treatment of hypogonadism; prevention and treatment of disorders of glucose metabolism. Careful attention to the endocrine aspects of PWS contributes significantly to the health of these individuals. Arch Endocrinol Metab. 2020;64(3):223-34.

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.

Effects of recombinant human growth hormone treatment on growth, body composition, and safety in infants or toddlers with Prader-Willi syndrome: a randomized, active-controlled trial

Background

Prader-Willi syndrome (PWS) is a rare complex genetic disorder and is characterized by short stature, muscular hypotonia, abnormal body composition, psychomotor retardation, and hyperphagia. Recombinant human growth hormone (rhGH) treatment improves the symptoms in children with PWS, and early treatment results in more favorable outcomes. However, systematic studies in infants and toddlers under 2 years of age are lacking. This multicenter, randomized, active-controlled, parallel-group, open-label, Phase III study aimed to evaluate the safety of rhGH (Eutropin, LG Chem, Ltd.) and its efficacy on growth, body composition, and motor and cognitive development in infants and toddlers with PWS compared with a comparator treatment (Genotropin, Pfizer, Inc.). Eligible Korean infants or toddlers with PWS were randomly assigned to receive Eutropin or comparator (both 0.24 mg/kg/week, 6 times/week) for 1 year. Height standard deviation score (SDS), body composition, and motor and cognitive development were measured.

Results

Thirty-four subjects (less than 24 months old) were randomized into either the Eutropin (N = 17) group or the comparator (N = 17) group. After 52 weeks of rhGH treatment, height SDS and lean body mass increased significantly from baseline in both groups: the mean height SDS change (SD) was 0.75 (0.59) in the Eutropin group and 0.95 (0.66) in the comparator group, and the mean lean body mass change (SD) was 2377.79 (536.25) g in the Eutropin group and 2607.10 (641.36) g in the comparator group. In addition, percent body fat decreased significantly: the mean (SD) change from baseline was − 8.12% (9.86%) in the Eutropin group and − 7.48% (10.26%) in the comparator group. Motor and cognitive developments were also improved in both groups after the 1-year treatment. The incidence of adverse events was similar between the groups.

Conclusions

rhGH treatment for 52 weeks in infants and toddlers with PWS improved growth, body composition, and motor and cognitive development, and efficacy and safety outcomes of Eutropin were comparable to those of Genotropin. Hence, Eutropin is expected to provide safe and clinically meaningful improvements in pediatric patients with PWS.

Trial registration

The study was registered at ClinicalTrials.gov (identifier: NCT02204163) on July 30, 2014.

URL: https://clinicaltrials.gov/ct2/show/NCT02204163?term=NCT02204163&rank=1

Safety and effectiveness of growth hormone therapy in infants with Prader-Willi syndrome younger than 2 years: a prospective study

Background There is little evidence of the effects of early treatment with growth hormone (GH) in infants with Prader-Willi syndrome (PWS). A prospective study was conducted to assess the safety of GH therapy in infants younger than 2 years of age with PWS. Methods A total of 14 patients with PWS started treatment with GH under the age of 2 years and were followed over a 2-year period. A deletion of chromosome 15 was present in nine infants (64.3%) and maternal uniparental disomy 15 in five infants (35.7%). The median age at start of GH treatment was 9.6 months (interquartile range [IQR] 9.0-18.3 months). Changes in height standard deviation score (SDS), body mass index (BMI) SDS and subcapsular and tricipital skinfolds in the follow-up period were evaluated with a mixed-model regression analysis using the Package R. Results There were no fatal adverse events. A significant decrease (p < 0.001) in tricipital and subcapsular skinfold thickness, with an upward trend of height SDS and a downward trend of BMI SDS, was observed. Infants who started GH before 15 months of age started walking at a median of 18.0 [17.0-19.5] months vs. 36.6 [36.3-37.8] months for those who began treatment with GH after 15 months of age (p = 0.024). Conclusions GH treatment in infants with PWS less than 2 years of age is safe and improved body composition. Infants who received GH before the age of 15 months started to walk earlier.

Prevalence of growth hormone (GH) deficiency in previously GH-treated young adults with Prader-Willi syndrome

OBJECTIVE

Some features of subjects with Prader-Willi syndrome (PWS) resemble those seen in growth hormone deficiency (GHD). Children with PWS are treated with growth hormone (GH), which has substantially changed their phenotype. Currently, young adults with PWS must discontinue GH after attainment of adult height when they do not fulfil the criteria of adult GHD. Limited information is available about the prevalence of GHD in adults with PWS. This study aimed to investigate the GH/insulin-like growth factor (IGF-I) axis and the prevalence of GHD in previously GH-treated young adults with PWS.

DESIGN

Cross-sectional study in 60 young adults with PWS.

MEASUREMENTS

Serum IGF-I and IGFBP-3 levels, GH peak during combined growth hormone-releasing hormone (GHRH)-arginine stimulation test.

RESULTS

Serum IGF-I was <-2 standard deviation scores (SDS) in 2 (3%) patients, and IGFBP-3 was within the normal range in all but one patient. Median (IQR) GH peak was 17.8 μg/L (12.2; 29.7) [~53.4 mU/L] and below 9 μg/L in 9 (15%) patients. Not one patient fulfilled the criteria for adult GHD (GH peak < 9 μg/L and IGF-I < -2 SDS), also when BMI-dependent criteria were used. A higher BMI and a higher fat mass percentage were significantly associated with a lower GH peak. There was no significant difference in GH peak between patients with a deletion or a maternal uniparental disomy (mUPD).

CONCLUSIONS

In a large group of previously GH-treated young adults with PWS, approximately 1 in 7 exhibited a GH peak <9 μg/L during a GHRH-arginine test. However, none of the patients fulfilled the consensus criteria for adult GHD.

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

OBJECTIVE

To carry out a review about Prader-Willi Syndrome based on the most recent data about the subject and to give recommendation for the general pediatricians for early diagnoses and follow-up.

DATA SOURCES

Scientific articles in the PubMed and SciELO databases. The research was not limited to a specific time period and included all articles in such databases.

DATA SYNTHESIS

The Prader-Willi Syndrome (PWS) is a rare genetic disorder resulting from the loss of imprinted gene expression within the paternal chromosome 15q11-q13. PWS is characterized by endocrine abnormalities, such as growth hormone (GH) deficiency, obesity, central adrenal insufficiency, hypothyroidism, hypogonadism and complex behavioral and intellectual difficulties. PWS individuals also may present other comorbidities, such as sleep disorders, scoliosis, constipation, dental issues and coagulation disorders. The follow-up protocol of the Children's Institute at Universidade de São Paulo is based on four main pillars: diet, exercise, recombinant human growth hormone (rhGH) therapy and behavioral and cognitive issues. The diet must include a caloric restriction of 900 kcal/day, according to the Prader-Willi Eating Pyramid and exercise plan is focused on daily aerobic exercises and postural therapy. The rhGH therapy is highly recommended by the international scientific literature and must be started as soon as the diagnostic is made. The management of behavioral issues is based on strategies to establish routine and rules.

CONCLUSIONS

If the general pediatrician becomes more familiar with PWS, the diagnosis and treatment will start earlier, which is essential to improve the quality of life and care for these individuals.

Early motor and pre-linguistic verbal development in Prader-Willi syndrome - A case report

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disorder. Infants with PWS show a neurodevelopmental dysfunction which entails a delayed motor and language development, but studies on their spontaneous movements (i.e. general movements) or pre-linguistic speech-language development before 6 months of age are missing so far.

AIM

To describe early motor and pre-linguistic verbal development in an infant with PWS.

METHODS AND PROCEDURES

Prospective case report; in addition to the assessment of general movements and the concurrent movement repertoire, we report on early verbal forms, applying the Stark Assessment of Early Vocal Development-Revised.

OUTCOMES AND RESULTS

General movements were abnormal on days 8 and 15. No fidgety movements were observed at 11 weeks; they only emerged at 17 weeks and lasted until at least 27 weeks post-term. The movement character was monotonous, and early motor milestones were only achieved with a delay. At 27 weeks the infant produced age-adequate types of vocalisations. However, none of the canonical-syllable vocalisations that typically emerge at that age were observed. Early vocalisations appeared monotonous and with a peculiarly harmonic structure.

CONCLUSIONS AND IMPLICATIONS

Early motor and pre-linguistic verbal behaviours were monotonous in an infant with PWS throughout his first 6 months of life. This suggests that early signs of neurodevelopmental dysfunction (i.e. abnormal general movements) might already be diagnosed in infants with PWS during their first weeks of life, potentially enabling us to diagnose and intervene at an early stage.

Contributing factors of mortality in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a multi-system disorder resulting from a lack of paternal gene expression in the 15q11.2-q13 region. Using databases compiled through response questionnaires completed by families known to the Prader-Willi Syndrome Association (USA), this study tested the hypothesis that PWS genetic subtype, BMI, age of diagnosis, clinical symptoms, and growth hormone treatment differ among deceased and living individuals with PWS. Categorical and continuous variables were compared using chi-square and two-group t tests, respectively. Deceased individuals had higher rates of clinical features, including increased weight concerns, heart problems, sleep apnea, other respiratory complications, diabetes, osteoporosis, high pain tolerance, and severe skin picking, when compared to living individuals. Meanwhile, living individuals had higher rates of growth hormone use and early puberty. Obesity and subsequent consequences are the primary contributors to increased mortality in PWS. Additional emphasis on areas to decrease mortality is needed.

Hypermobility in individuals with Kabuki syndrome: The effect of growth hormone treatment

Kabuki syndrome (KS) is a multiple congenital malformation syndrome which has been described across all ethnic groups. Most KS patients possess two genetic subtypes: KMT2D-associated, autosomal-dominant KS type 1 (KS1; OMIM 147920); and KDM6A-associated, X-linked-dominant KS type 2. Generalized joint hypermobility is one feature of KS, but its exact incidence and pattern is not well described in the literature. As part of our prospective study on the metabolic and growth effect of GH treatment, we assessed children from our Dutch Kabuki cohort who were eligible for growth hormone therapy. We assessed severity and pattern of joint hypermobility, both before and after 24 months of growth hormone replacement therapy. The prevalence of hypermobility was 31% in boys and 14% in girls using the Beighton score and 69% in boys and 57% in girls using the Bulbena score. This varies from the general population where girls are more affected. After 2 years of growth hormone treatment, there was a statistically significant decrease in the presence of joint hypermobility to 6% using the Bulbena score and none with respect to the Beighton score. We hypothesized that this result suggests a direct effect of growth hormone on connective tissue in patients with KS.

EFFECT OF GROWTH HORMONE THERAPY IN CHILDREN WITH PRADER-WILLI SYNDROME - OUR FIRST EXPERIENCES

- Prader-Willi syndrome (PWS) is the most common cause of morbid obesity in childhood. It is the consequence of the lack of expression of genes on the paternally inherited 15q11.2-q13 region. Hyperphagia, obesity, short stature, psychomotor retardation and deterioration of behavior predominate in clinical presentation. Recombinant human growth hormone (rhGH) therapy, along with restriction of caloric intake, has become the mainstay in the management of PWS patients. Anthropometric parameters (height, body mass index (BMI)), therapy effect on carbohydrate and lipid metabolism, and occurrence of side effects were monitored in four children with PWS treated with rhGH for ≥2 years at doses of up to 1 mg/m2/day. During the follow-up, the height standard deviation score (SDS) increased in comparison with baseline values, and after ≥2 years of treatment with rhGH it was within the reference range for the general children population. BMI SDS decreased after the first year of treatment, but thereafter increased again; still, the level of BMI SDS was much better in comparison with most children with PWS of the same age and gender. RhGH therapy had no negative effect on glucose and lipid metabolism, nor caused any other adverse effect. Therapy including a customized diet for PWS, along with rhGH therapy, provided a satisfactory growth rate and prevented development of morbid obesity without side effects. This treatment approach would ensure transition of a greater number of PWS patients into adult care, where the multidisciplinary approach in care should be continued.

Improved Mental and Motor Development During 3 Years of GH Treatment in Very Young Children With Prader-Willi Syndrome

CONTEXT

Infants and toddlers with Prader-Willi syndrome (PWS) have mental and motor developmental delay. Short-term data suggest a positive effect of GH on mental and motor development in infants and children with PWS. There are, however, no longer-term results about the effects of GH treatment on mental and motor development.

OBJECTIVE

To investigate the longer-term effects of GH on psychomotor development in infants and toddlers with PWS and the effect of age at start of GH treatment on psychomotor development.

DESIGN

Prospective cohort study during 3 years of GH treatment.

SETTING

The PWS Reference Center in the Netherlands.

INTERVENTION

All children were treated with GH 1 mg/m2/d (≈0.035 mg/kg/d).

MAIN OUTCOME MEASURES

Mental and motor developmental age assessed with Bayleys Scales of Infant Development II and expressed as percentage of the expected development (100%).

RESULTS

During 3 years of GH, mean (SEM) mental development increased from 58.1% (2.8) at baseline to 79.6% (3.7), and motor development increased from 41.9% (2.9) to 78.2% (3.9; both P < 0.01). A lower baseline psychomotor development and a younger age at start of GH treatment were associated with a higher increase in mental and motor development (P < 0.01).

CONCLUSIONS

Mental and motor development increased significantly during 3 years of GH treatment, reducing the gap between infants with PWS and healthy peers. A younger age at start of GH treatment leads to greater improvement in psychomotor development.

Neonatal Features of the Prader-Willi Syndrome; The Case for Making the Diagnosis During the First Week of Life

OBJECTIVE

Early diagnosis is of proven benefit in Prader-Willi syndrome (PWS). We therefore examined key perinatal features to aid early recognition.

METHODS

Data were collected from case records of subjects attending a multi-disciplinary clinic and from a retrospective birth questionnaire.

RESULTS

Ninety patients (54 male-36 female) were seen between 1991-2015, most with paternal deletion (n=56) or maternal isodisomy (n=26). Features included cryptorchidism in 94% males, preterm birth (26%), birthweight <2500 g (24%), polyhydramnios (23%), breech presentation (23%) and need for nasogastric feeding (83%). Reduced fetal movements (FM) were reported in 82.5% patients compared with 4% healthy siblings. Of 35 children born since 1999, 23 were diagnosed clinically within 28 days while diagnosis in 12 was >28 days: 1-12 months in seven; and 3.75-10.5 years in five. Typical PWS features in these 12 infants included hypotonia (100%), feeding difficulties (75%), cryptorchidism (83% males) and reduced FM (66%). Causes other than PWS including neuromuscular disease were considered in nine patients.

CONCLUSION

Neonatal hypotonia, reduced FM, feeding difficulties and cryptorchidism should immediately suggest PWS, yet late diagnosis continues in some cases. Awareness of the typical features of PWS in newborn units is required to allow prompt detection even in the presence of confounding factors such as prematurity.

A Novel Mutation of MAGEL2 in a Patient with Schaaf-Yang Syndrome and Hypopituitarism

INTRODUCTION

Schaaf-Yang syndrome (SYS) is caused by truncating point mutations of the paternal allele of MAGEL2, an imprinted gene located in the critical region of Prader-Willi syndrome (PWS). These patients present a phenotype with neurodevelopmental delay, hypotonia, joint contractures, and a particularly high prevalence of autism (up to 75% in affected individuals). The loss of function of MAGEL2 is suggested to contribute to endocrine hypothalamic dysfunction in individuals with PWS.

CASE PRESENTATION

The current study presented the case of a patient with SYS and a novel de novo truncating mutation of MAGEL2 and phenotypic characteristics typical of this Prader-Willi-like syndrome and also including partial hypopituitarism, hypothyroidism, growth hormone deficiency, and hyperprolactinemia.

CONCLUSIONS

The clinical and molecular similarities between SYS and PWS suggested the need for a thorough endocrinological follow-up to improve the prognosis and long-term quality of life for patients with SYS.

Bone mineral density in young adults with Prader-Willi syndrome: A randomized, placebo-controlled, crossover GH trial

CONTEXT

The prevalence of osteoporosis is increased in adults with Prader-Willi syndrome (PWS). In children with PWS, growth hormone (GH) treatment has beneficial effects on bone mineral density (BMD). BMD might deteriorate after cessation of GH at adult height (AH), while continuing GH might maintain BMD.

OBJECTIVE

To investigate the effects of GH vs placebo, and furthermore the effects of sex steroid replacement therapy (SSRT), on BMD in GH-treated young adults with PWS who had attained AH.

DESIGN

Two-year, randomized, double-blind, placebo-controlled, crossover GH study.

PATIENTS

Twenty-seven young adults with PWS were stratified for gender and BMI and then randomly and blindly assigned to receive GH (0.67 mg/m² /day) or placebo for 1 year, after which they crossed over to the alternative treatment for another year.

MEASUREMENTS

Bone mineral density of the total body (BMD_TB ) and lumbar spine (BMD_LS ) SDS were measured by dual-energy x-ray absorptiometry.

RESULTS

At AH, BMD_TB SDS was significantly lower compared to healthy peers (P < .01), while BMAD_LS SDS was similar. Both BMD_TB SDS and BMAD_LS SDS were similar during 1 year of GH vs 1 year of placebo. In hypogonadal young adults without SSRT, BMD_TB SDS and BMAD_LS SDS decreased during the 2-year study (P = .11 and P = .01), regardless of GH or placebo, while BMD_TB SDS increased in those with SSRT (P < .01).

CONCLUSIONS

Compared to GH treatment, 1 year of placebo after attainment of AH does not deteriorate BMD SDS in young adults with PWS. In addition, our data suggest that GH is not able to prevent the decline in BMD SDS in hypogonadal young adults with PWS, unless it is combined with SSRT.

Treatment with growth hormone in the prader-willi syndrome

INTRODUCTION

The Prader-Willi syndrome (PWS) is a rare genetic disorder caused by absence of expression of the paternal alleles in región 15q11.2-q13. Obesity and hormonal deficiencies, especially of growth hormone (GH), are the most important signs from the therapeutic viewpoint. Recombinant GH (rGH) is effective in children and represents the mainstay in treatment; by contrast, little evidence in available in adult patients.

OBJECTIVE

To review the reported evidence on the beneficial and adverse effects of treatment with rGH in children and adults.

DESIGN

A review was made of 62 original articles published between 2000 and 2017 using the PubMed database.

RESULTS

In pediatric and adult PWS, rGH improves body morphology and composition, physical performance, cognition, psychomotor development, respiratory function, and quality of life with few adverse effects.

CONCLUSIONS

Treatment with rGH is effective and safe and improves quality of life in both children and adults with PWS.

Aberrant White Matter Microstructure in Children and Adolescents With the Subtype of Prader-Willi Syndrome at High Risk for Psychosis

Prader-Willi Syndrome (PWS) is a complex neurogenetic disorder caused by loss of the paternal 15q11.2-q13 locus, due to deletion (DEL), maternal uniparental disomy (mUPD), or imprinting center defects. Individuals with mUPD have up to 60% risk of developing psychosis in early adulthood. Given the increasing evidence for white matter abnormalities in psychotic disorders, we investigated white matter microstructure in children and adolescents with PWS, with a particular emphasis on the DEL and mUPD subtypes. Magnetic resonance diffusion weighted images were acquired in 35 directions at 3T and analyzed using fractional anisotropy (FA), mean, axial, and radial diffusivity (MD, AD, RD) values obtained by tract-based spatial statistics (TBSS) in 28 children and adolescents with PWS and 61 controls. In addition, we employed a recently developed white matter pothole approach, which does not require local FA differences to be spatially co-localized across subjects. After accounting for age and gender, individuals with PWS had significantly lower global FA and higher MD, compared with controls. Individuals with mUPD had lower FA in multiple regions including the corpus callosum, cingulate, and superior longitudinal fasciculus and larger potholes, compared with DEL and controls. The observed differences in individuals with mUPD are similar to the white matter abnormalities in individuals with psychotic disorders. Conversely, the subtle white matter abnormalities in individuals with DEL are consistent with their substantially lower risk of psychosis. Future studies to investigate the specific neurobiological mechanism underlying the differential psychosis risk between the DEL and mUPD subtypes of PWS are highly warranted.

Longitudinal evaluation of sleep disordered breathing in infants with Prader-Willi syndrome

OBJECTIVE

To evaluate the course of sleep disordered breathing (SDB) in infants with Prader-Willi syndrome (PWS).

DESIGN

Retrospective longitudinal observational study.

SETTING

Sleep laboratory at The Hospital for Sick Children, Toronto, Canada.

PATIENTS

Infants with PWS.

MAIN OUTCOME MEASURES

The natural history of SDB in infants with PWS within 2 years from baseline assessment.

RESULTS

We identified 28 (12 male) infants with PWS who had a baseline polysomnography (PSG) at a median age (interquartile (IQR)) of 0.9 (0.5, 1.1) years. The median central apnoea index (CAI) at baseline was 6.6 events/hour (IQR 2.6, 12.1). Of these, 15/28 (53%) infants with PWS were diagnosed with significant central sleep apnoea (CSA) (CAI≥5 events/hour). Median age (IQR) at follow-up PSG was 2.1 (1.5, 2.6) years. The median CAI improved from 6.6 to 2.3 events/hour (p<0.0001). Only four infants with PWS had persistent CSA at the time of the follow-up PSG. Furthermore, three infants with PWS were diagnosed with mild-to-moderate obstructive sleep apnoea (OSA) that has improved at follow-up studies whereas two patients with PWS with no evidence of OSA at baseline were diagnosed with severe OSA on the follow-up PSG requiring adenotonsillectomy. The overall median obstructive apnoea-hypopnoea index was similar between baseline and follow-up studies (0.6 and 0.8, respectively, p=0.91).

CONCLUSIONS

CSA is prevalent in infants with PWS but usually improves with age. However, these patients continue to require ongoing PSG surveillance because some infants will have persistent CSA and others are at risk of developing OSA.

Early diagnosis and care is achieved but should be improved in infants with Prader-Willi syndrome

Background

PWS is a severe neurodevelopmental genetic disorder now usually diagnosed in the neonatal period from hypotonia and feeding difficulties. Our study analyzed the birth incidence and care of infants with early diagnosis.

Methods

Data were collected on 61 infants with a molecular diagnosis of PWS born in 2012 and 2013 in France.

Results

Thirty-eight infants with PWS were born in 2013. The median age at diagnosis was 18 days. Birth incidence calculated for 2013 was 1/21,000 births. No case was diagnosed prenatally, despite 9 amniocenteses, including 4 for polyhydramnios. Five infants had delayed diagnosis, after 3 months of life. For 2 of them, the diagnosis was not suspected at birth and for 3, FISH analysis in the neonatal period was normal, with no further molecular studies. Ninety-three percent of the neonates were hospitalized, and 84% needed nasogastric tube feeding for a median of 38 days. Swallowing assessment was performed for 45%, at a median age of 10 days. Physiotherapy was started for 76% during hospitalization. Eighty percent of those diagnosed within the first 3 months were seen by a pediatric endocrinologist within the first week of life.

Conclusion

Our study is the first to assess the birth incidence of PWS in France, at 1/21,000 births. Some prenatal or neonatal cases remain undiagnosed because of unrecognized clinical signs and the inappropriate choice of the initial molecular test. We also underscore the need to optimize neonatal care of infants with PWS.

[Neuropsychiatric aspects of Prader-Willi syndrome – a review]

Prader-Willi Syndrome (PWS) is caused by the absence of paternal expression of imprinted genes in the region at 15q11–q13. With an estimated birth incidence of 1/15 000 – 1/30 000, PWS is one of the more frequent genetic syndromes among humans. Typical physical features include neonatal hypotonia and feeding problems, hypogonadism, hyperphagia in later childhood with consecutive obesity, and short stature. Most people with PWS show a mild to moderate intellectual disability. Furthermore, lability of mood, temper tantrums, skin-picking, and compulsive behaviors are quite typical for subjects with PWS. Psychotic disorders have also been found to be quite common in adulthood. This manuscript reviews current knowledge about the etiology, physical features, developmental aspects, behavioral phenotype, and psychiatric disorders that occur as well as existing psychopharmacological and psychotherapeutic interventions.

Low dose growth hormone treatment in infants and toddlers with Prader-Willi syndrome is comparable to higher dosage regimens

OBJECTIVE

Evaluate benefit and risk of low dose growth hormone treatment (GHT, 4.5mg/m²/week) in very young children with Prader-Willi Syndrome (PWS).

DESIGN

Prospective longitudinal clinical intervention.

METHODS

We evaluated 31 infants (aged 2-12months) and 42 toddlers (13-24months) from the PWS-OZGROW database for height, weight and BMI using the World Health Organization standard deviation scores (SDS_WHO) and PWS specific BMI (SDS_PWS), bone age, insulin-like growth factor 1 (IGF-I) levels and adverse events over 3years of GHT.

RESULTS

At commencement of GHT infants had a lower BMI SDS_WHO (-0.88 vs 0.40) than toddlers, while toddlers had a lower height SDS_WHO (-1.44 vs -2.09) (both P<0.05). All increased height SDS_WHO (2year delta height infants +1.26 SDS, toddlers+1.21 SDS), but infants normalised height sooner, achieving a height SDS of -0.56 within 1year, while toddlers achieved a height SDS of -0.88 in two years. BMI SDS_WHO increased, while BMI SDS_PWS decreased (both P<0.0001) and remained negative. The GHT response did not differ with gestation (preterm 23%) or genetic subtype (deletion vs maternal uniparental disomy). Bone age advancement paralleled chronological age. All children had low serum IGF-I at baseline which increased, but remained within the age-based reference range during GHT (for 81% in first year). Four children had spinal curvature at baseline; two improved, two progressed to a brace and two developed an abnormal curve over the observation period. Mild to severe central and/or obstructive sleep apnoea were observed in 40% of children prior to GHT initiation; 11% commenced GHT on positive airway pressure (PAP), oxygen or both. Eight children ceased GHT due to onset or worsening of sleep apnoea: 2 infants in the first few months and 6 children after 6-24months. Seven resumed GHT usually after adjusting PAP but five had adenotonsillectomy. One child ceased GHT temporarily due to respiratory illness. No other adverse events were reported. Two children substantially improved their breathing shortly after GHT initiation.

CONCLUSION

Initiation of GHT in infants with 4.5mg/m²/week was beneficial and comparable in terms of auxological response to a dose of 7mg/m²/week. Regular monitoring pre and post GH initiation assisted in early detection of adverse events. IGF-I levels increased with the lower dose but not excessively, which may lower potential long-term risks.

Rigidity in routines and the development of resistance to change in individuals with Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) commonly show debilitating resistance to change, which has been linked to cognitive deficits in task switching. Anecdotal reports suggest that exposure to flexibility in routines during development may be beneficial for limiting subsequent resistance to change in people with PWS, which is consistent with a beneficial role of such exposure on the development of task switching, highlighted in typical children. Here, we aim to investigate the development of resistance to change in individuals with PWS and hypothesise that exposure to increased rigidity in routines will be associated with increased subsequent resistance to change.

METHODS

An author-compiled informant report interview and two previously validated questionnaires were administered to the caregivers of 10 individuals with PWS (5-23 years). The interview examined rigidity in routines and resistance to change across life stages defined by easily distinguishable events (before school, during primary school, during secondary school, after school, currently), using open-ended and structured yes/no and 5-point Likert questions. Open-ended data were coded using an author-compiled system. Responses from two additional informants and data from the questionnaires were used to assess inter-informant reliability and concurrent validity of the structured questions.

RESULTS

The validity of the interview was supported by acceptable inter-rater reliability of the open-ended coding system and inter-informant reliability, internal consistency and concurrent validity of structured questions. Descriptive analyses of ratings of behaviour change showed a pattern of increasing resistance to change over the life course for the four oldest individuals, who had all been exposed to substantial rigidity in routines before and during primary school. Furthermore, only one individual - currently in primary school - was exposed to very little rigidity in routines before and during primary school, and he had showed a decrease in resistance to change after entering primary school. Open-ended data showed that more individuals currently evidencing little resistance to change had been exposed to parent or self-imposed flexibility in routines, than those currently evidencing substantial resistance to change. However, correlational analyses on rigidity and resistance to change ratings highlighted the possibility that rigidity during primary school is most relevant for developing resistance to change. Finally, open-ended data emphasised an important beneficial role of rigidity in routines for limiting the current challenging behaviour of individuals with high resistance to change.

CONCLUSION

Because task switching appears to evidence a period of high developmental sensitivity during early primary school years, we propose that this period may represent a critical time when increasing flexibility in the routines of children with PWS could limit the development of resistance to change. However, a careful balance would need to be struck, given the apparent benefit of rigid routines on current behaviour. Further work in this area is much needed.

Growth Hormone Treatment in Children With Prader-Willi Syndrome: Three Years of Longitudinal Data in Prepubertal Children and Adult Height Data From the KIGS Database

CONTEXT

Longitudinal data of children with Prader-Willi syndrome (PWS) treated with genotropin were registered in the Pfizer International Growth Database (KIGS).

OBJECTIVE

To evaluate efficacy and safety of growth hormone (GH) treatment in a large group of children with PWS.

DESIGN

Data registered in KIGS from 1987 to 2012.

SETTING

Worldwide retrospective cohort study.

PATIENTS

Patients included 522 prepubertal children treated with GH for three years and 173 children who had reached adult height. Safety analysis included 2332 children. Intervention involved GH treatment.

MAIN OUTCOME MEASURE

Height standard deviation score (SDS), body mass index (BMI) SDS, occurrence of serious adverse events, and deaths reported in KIGS.

RESULTS

In prepubertal children, mean (standard deviation) height SDS improved to -0.31 (1.34) (P < 0.05) during three years of GH treatment. In the adolescent group, height SDS improved until the start of puberty to -0.22 (1.31) (P < 0.05) but had a loss of -0.77 (0.81) during puberty, resulting in a mean adult height SDS of -1.19 (1.37). Total height gain was 0.95 (1.32) SDS. BMI SDS increased in the prepubertal group from 1.11 (2.09) to 1.53 (1.43) (P < 0.05) and did not significantly change in the adolescent group, who had a BMI SDS at an adult height of 1.78 (1.26). KIGS contained 12 death reports.

CONCLUSIONS

GH treatment in children with PWS significantly improves linear growth. BMI remains on average below +2 SDS, in contrast to the natural course of increasing obesity in PWS. Safety should be closely monitored in children with PWS, with and without GH treatment.

Certainty of genuine treatment increases drug responses among intellectually disabled patients

Objective:

To determine the placebo component of treatment responses in patients with intellectual disability (ID).

Methods:

A statistical meta-analysis comparing bias-corrected effect sizes (Hedges g) of drug responses in open-label vs placebo-controlled clinical trials was performed, as these trial types represent different certainty of receiving genuine treatment (100% vs 50%). Studies in fragile X, Down, Prader-Willi, and Williams syndrome published before June 2015 were considered.

Results:

Seventeen open-label trials (n = 261, 65% male; mean age 23.6 years; mean trial duration 38 weeks) and 22 placebo-controlled trials (n = 721, 62% male; mean age 17.1 years; mean trial duration 35 weeks) were included. The overall effect size from pre to post treatment in open-label studies was g = 0.602 (p = 0.001). The effect of trial type was statistically significant (p = 0.001), and revealed higher effect sizes in studies with 100% likelihood of getting active drug, compared to both the drug and placebo arm of placebo-controlled trials. We thus provide evidence for genuine placebo effects, not explainable by natural history or regression toward the mean, among patients with ID.

Conclusions:

Our data suggest that clinical trials in patients with severe cognitive deficits are influenced by the certainty of receiving genuine medication, and open-label design should thus not be used to evaluate the effect of pharmacologic treatments in ID, as the results will be biased by an enhanced placebo component.