Feeding tube use and complications in Prader-Willi syndrome: Data from the Global Prader-Willi Syndrome Registry

Guidance on indications for, and types of, feeding tubes recommended in Prader-Willi syndrome (PWS) is needed. A Global PWS Registry survey was developed to investigate nasogastric (NG) and gastrostomy (G) tube use and associated complications. Of 346 participants, 242 (69.9%) had NG-tubes, 17 (4.9%) had G-tubes, and 87 (25.1%) had both NG- and G-tubes. Primary indication for placement was "feeding difficulties and/or poor weight gain" for both NG- (90.2%) and G-tubes (71.2%), while "aspiration/breathing difficulties" was the procedural indication for 6.4% of NG-tubes and 23.1% of G-tubes. NG-tubes were generally removed by age 6 months (NG Only: 82.9%; NG/G: 98.8%), while G-tubes were often removed by age 2 years (G Only: 85.7%; NG/G: 70.5%). The severe complication rate from G-tubes was 31.7% and from NG-tubes was 1.2%. Overall, caregivers indicated the presence of an NG- or G-tube had a positive effect on quality of life. Feeding difficulties in PWS are largely managed by NG-tube alone. The severe complication rate from G-tubes was about 25 times higher than from NG-tubes; yet, G-tube placement rates have generally increased. G-tube placement puts individuals with PWS at risk for anesthesia and surgery-related complications and should be considered judiciously by a multidisciplinary team.

Genotype-phenotype correlation in Prader-Willi syndrome: A large-sample analysis in China

The genotype-phenotype relationship in PWS patients is important for a better understanding of the clinical phenotype and clinical characteristics of different genotypes of PWS in children. We aimed to explore the influence of specific gene changes on the clinical symptoms of PWS and the value of early screening and early intervention of the condition. All data in this study were extracted from the database of the XiaoPang Weili Rare Disease Care Center. The collected information included basic demographics, maternal pregnancy information, endocrine abnormalities, growth and development abnormalities, and other clinical phenotypes. The relationships between genotypes and phenotypes in the major categories of PWS were analyzed. A total of 586 PWS cases with confirmed molecular diagnosis and genotyping were included in this study. Among them, 83.8% belonged to the deletion type, 10.9% the uniparental disomy (UPD) type, and 5.3% the imprinting defect (ID) type. Age-wide comparison among the three groups: The rate of hypopigmentation in the deletion group was higher than that in the UPD group (88.8% vs. 60.9%; p < 0.05); A total of 62 patients (14.2%) had epilepsy; and no statistical significance was found among the three groups (p = 0.110). Age-wide comparison between the deletion and non-deletion types: the rate of skin hypopigmentation and epilepsy in the deletion group was significantly higher than that in the non-deletion group (88.8% vs. 68.4%, p < 0.001; 15.9% vs. 7.6%, p = 0.040). The intergroup comparison for the >2-year age group: there were significant intergroup differences in the language development delay among the three groups (p < 0.001). The incidence of delayed language development was the highest in the deletion group, followed by the UPD group, and the lowest in the ID group. The rates of obesity and hyperphagia in the deletion group were also higher than those in the non-deletion group (71.1% vs. 58.9%, p = 0.041; 75.7% vs. 62.0%, p = 0.016). There are significant differences in the rates of skin hypopigmentation and language developmental delay among the deletion, UPD, and ID genotypes. The patients with deletion type had significantly higher rates of lighter skin color, obesity, hyperphagia, language developmental delay, and epilepsy. The results of this study will help clinicians better understand the impact of different PWS molecular etiologies on specific phenotypes.

Malignancies in Prader-Willi Syndrome: Results From a Large International Cohort and Literature Review

CONTEXT

Prader-Willi syndrome (PWS) is a complex disorder combining hypothalamic dysfunction, neurodevelopmental delay, hypotonia, and hyperphagia with risk of obesity and its complications. PWS is caused by the loss of expression of the PWS critical region, a cluster of paternally expressed genes on chromosome 15q11.2-q13. As life expectancy of patients with PWS increases, age-related diseases like malignancies might pose a new threat to health.

OBJECTIVE

To investigate the prevalence and risk factors of malignancies in patients with PWS and to provide clinical recommendations for cancer screening.

METHODS

We included 706 patients with PWS (160 children, 546 adults). We retrospectively collected data from medical records on past or current malignancies, the type of malignancy, and risk factors for malignancy. Additionally, we searched the literature for information about the relationship between genes on chromosome 15q11.2-q13 and malignancies.

RESULTS

Seven adults (age range, 18-55 years) had been diagnosed with a malignancy (acute lymphoblastic leukemia, intracranial hemangiopericytoma, melanoma, stomach adenocarcinoma, biliary cancer, parotid adenocarcinoma, and colon cancer). All patients with a malignancy had a paternal 15q11-13 deletion. The literature review showed that several genes on chromosome 15q11.2-q13 are related to malignancies.

CONCLUSION

Malignancies are rare in patients with PWS. Therefore, screening for malignancies is only indicated when clinically relevant symptoms are present, such as unexplained weight loss, loss of appetite, symptoms suggestive of paraneoplastic syndrome, or localizing symptoms. Given the increased cancer risk associated with obesity, which is common in PWS, participation in national screening programs should be encouraged.

Scoliosis and BMI in patients with Prader-Willi syndrome

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

Prevalence of Sleep-Disordered Breathing in Prader-Willi Syndrome

Introduction

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

Objectives

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

Methods

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

Results

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

Conclusion

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

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.

Perinatal and neonatal characteristics of Prader-Willi syndrome in Japan

BACKGROUND

Prader-Willi syndrome (PWS) is suspected at birth if extreme hypotonia, difficulty in feeding, hypogonadism, and failure to thrive are present. Genetic diagnosis of PWS can generally be made within the first few months of life; however, a delayed diagnosis of PWS is frequently reported. Although the clinical characteristics of perinatal and neonatal patients with PWS have been reported, there are no such reports on the clinical characteristics of these patients in Japan.

METHODS

This retrospective, single-center study involved 177 Japanese patients with PWS and their medical data regarding the perinatal and neonatal periods were evaluated.

RESULTS

The median maternal age at birth was 34 years; 12.7% of the mothers had a history of assisted reproductive technology (ART). Of the mothers, 13.5% reported polyhydramnios and 4.3% had oligohydramnios. Decreased fetal movement during pregnancy was reported by 76% of the mothers. A total of 60.5% of patients were born by cesarean section. Genetic subtypes included deletions (66.1%), uniparental disomy (31.0%), imprinting defects (0.6%), and other or unknown subtypes (2.3%). The median birth length was 47.5 cm and the median birthweight was 2476 g. Of the 160 patients, 14 (8.8%) were classified as small for gestational age. Most patients had hypotonia (98.8%), and 89.3% required gavage feeding at birth. Breathing problems, congenital heart disease, and undescended testis were noted in 33.1%, 7.0%, and 93.5% of patients, respectively.

CONCLUSION

In our study, higher rates of ART, polyhydramnios, decreased fetal movements, cesarean section, hypotonia, feeding difficulties, and undescended testis were observed in PWS.

Bone Health in Adults With Prader-Willi Syndrome: Clinical Recommendations Based on a Multicenter Cohort Study

CONTEXT

Prader-Willi syndrome (PWS) is a rare complex genetic syndrome, characterized by delayed psychomotor development, hypotonia, and hyperphagia. Hormone deficiencies such as hypogonadism, hypothyroidism, and growth hormone deficiency are common. The combination of hypotonia, low physical activity, and hypogonadism might lead to a decrease in bone mass and increase in fracture risk. Moreover, one would expect an increased risk of scoliosis due to hypotonia and low physical activity.

OBJECTIVE

To study the prevalence and risk factors for skeletal problems (reduced bone mineral density, fractures, and scoliosis) in adults with PWS.

METHODS

We retrospectively collected patient characteristics, medical history, medication, biochemical measurements, dual-energy X-ray absorptiometry scans, and spinal X-rays and reviewed the current literature.

RESULTS

We included 354 adults with PWS (median age 31 years; 43% males), of whom 51 (14%) had osteoporosis (T-score below -2.5) and 143 (54%) had osteopenia (T-score -1 to -2.5). The most prevalent modifiable risk factors for osteoporosis were hypogonadism, insufficient dairy intake, sedentary lifestyle, and corticosteroid use. Male sex was associated with osteoporosis (P = .005). Growth hormone treatment was not associated with osteoporosis. A history of vertebral fractures was present in 10 (3%) and nonvertebral fractures in 59 (17%). Scoliosis was present in 263 (80%), but no modifiable risk factors were identified.

CONCLUSION

Besides scoliosis, osteoporosis is common in adults with PWS. Based on the literature and the risk factors for osteoporosis found in our cohort, we provide practical clinical recommendations to avoid skeletal complications in these vulnerable patients.

Demographics and medical comorbidities among hospitalized patients with Prader-Willi Syndrome: A National Inpatient Sample analysis

Prader-Willi Syndrome (PWS) is a multi-system genetic disorder characterized by hyperphagia and a range of medical complications. While register and cohort studies have explored the natural course of the syndrome, there is little nationally-representative data. In this study the National Inpatient Sample, a de-identified all-payors database of acute care hospital discharges in the United States, was queried for patients discharged with a diagnosis of PWS in 2019. Hospitalizations involving PWS were compared to hospitalizations without a PWS diagnosis matched based on demographic and hospital factors. In total, 540 hospitalizations (95% CI: 513-567) included a diagnosis of PWS. Median age at time of admission was 22 years, with an interquartile range of 6.3-37.8 years. Respiratory conditions accounted for 110 (20.4%) of primary discharge diagnoses, with infectious conditions for 70 (13.0%) and digestive conditions for 65 (12.0%). Hospitalizations involving PWS were significantly more likely to involve respiratory failure (OR 5.49; 95% CI 3.86-7.80), septicemia (OR 2.80, 95% CI 1.97-3.96), or intestinal obstruction and ileus (OR 6.29; 95% CI 3.70-10.7) compared to matched hospitalizations without PWS. Obesity was diagnosed in 230 PWS hospitalizations (42.6%; OR 3.86, 95% CI 3.17-4.72 relative to non-PWS hospitalizations). These results point to an ongoing need for the improved diagnosis and treatment of PWS complications, and highlight the importance of specific billing codes for rare diseases to enhance the collection of real world evidence.

Single-center real-life experience with testosterone treatment in adult men with Prader-Willi syndrome

Hypogonadism is the most frequent hormonal deficiency in individuals with Prader-Willi syndrome (PWS). This often necessitates testosterone treatment, but limited data are available to guide testosterone treatment in adult men with PWS. We aimed to evaluate the serum testosterone concentrations and adverse effects of testosterone treatment in individuals with PWS attending a specialist obesity management service. A retrospective audit was undertaken at Austin Health, Melbourne between January 2010 and April 2021. Main outcome measures were testosterone formulation and dose, serum total testosterone concentration, and prevalence of polycythemia and behavioral disturbance. Data were available for eight individuals with median baseline age 19 years (range, 19-42) and BMI 37 kg/m² (range, 27-71). Six men had obstructive sleep apnea; none were smokers. Baseline testosterone concentration was 1.8 nmol/L (IQR, 1.1-3.3) with hematocrit 0.43. Testosterone formulations were intramuscular testosterone undecanoate (TU) 1000 mg (n = 5), transdermal testosterone gel 50 mg daily (n = 1), and oral TU 80-120 mg daily (n = 2). Median total testosterone concentration was 9.7 nmol/L (IQR, 8.5-14.7). Nine of 25 (36%) hematocrit results in six patients measured >0.50 (range, 0.50-0.56). Intramuscular TU was well tolerated and was the only formulation to achieve serum total testosterone concentrations in the adult male reference range. Worsening behavioral disturbance resulted in treatment discontinuation in one individual. Our experience reinforces the need to regular monitoring of hematocrit in men with PWS treated with testosterone. However, a worsening of behavior problems was uncommon in this series.

Pediatric growth hormone treatment in Italy: A systematic review of epidemiology, quality of life, treatment adherence, and economic impact

Objectives

This systematic review aims to describe 1) the epidemiology of the diseases indicated for treatment with growth hormone (GH) in Italy; 2) the adherence to the GH treatment in Italy and factors associated with non-adherence; 3) the economic impact of GH treatment in Italy; 4) the quality of life of patients treated with GH and their caregivers in Italy.

Methods

Systematic literature searches were performed in PubMed, Embase and Web of Science from January 2010 to March 2021. Literature selection process, data extraction and quality assessment were performed by two independent reviewers. Study protocol has been registered in PROSPERO (CRD42021240455).

Results

We included 25 studies in the qualitative synthesis. The estimated prevalence of growth hormone deficiency (GHD) was 1/4,000–10,000 in the general population of children; the prevalence of Short Stature HOmeoboX Containing gene deficiency (SHOX-D) was 1/1,000–2,000 in the general population of children; the birth prevalence of Turner syndrome was 1/2,500; the birth prevalence of Prader-Willi syndrome (PWS) was 1/15,000. Treatment adherence was suboptimal, with a range of non-adherent patients of 10–30%. The main reasons for suboptimal adherence were forgetfulness, being away from home, pain/discomfort caused by the injection. Economic studies reported a total cost for a complete multi-year course of GH treatment of almost 100,000 euros. A study showed that drug wastage can amount up to 15% of consumption, and that in some Italian regions there could be a considerable over- or under-prescribing. In general, patients and caregivers considered the GH treatment acceptable. There was a general satisfaction among patients with regard to social and school life and GH treatment outcomes, while there was a certain level of intolerance to GH treatment among adolescents. Studies on PWS patients and their caregivers showed a lower quality of life compared to the general population, and that social stigma persists.

Conclusion

Growth failure conditions with approved GH treatment in Italy constitute a significant burden of disease in clinical, social, and economic terms. GH treatment is generally considered acceptable by patients and caregivers. The total cost of the GH treatment is considerable; there are margins for improving efficiency, by increasing adherence, reducing drug wastage and promoting prescriptive appropriateness.

[Psychiatric disorders in adults with Prader-Willi syndrome: a systematic literature review]

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic syndrome characterized by dysmorphic features and endocrine, cognitive and psychiatric problems. Psychiatric problems interfere with the transition from pediatric to adult care. Psychiatric expertise is needed to facilitate this transition.

AIM

To provide a literature review on the prevalence and clinical presentation of psychiatric disorders in adults with PWS.

METHOD

A systematic literature review following the PRISMA-guidelines.

RESULTS

Thirty-three articles were included. Most adults with PWS had a specific behavioral profile with disruptive, autistic and compulsive characteristics. Psychotic symptoms occured in one third of adults with PWS, mostly in patients with maternal uniparental disomy. Mood disorders were present in 10 to 20% of adults with PWS and often accompanied by psychotic features. Studies were limited and heterogeneous in samples and methods.

CONCLUSION

There is a broad spectrum of psychiatric symptoms in adults with PWS. The clinical presentation does not fully fit within the DSM categories and shows differences between genetic subgroups. Longitudinal studies assessing the psychiatric symptoms with standardized methods are needed to improve practices on diagnosing, prevention, and treatment.

Missed Diagnoses and Health Problems in Adults With Prader-Willi Syndrome: Recommendations for Screening and Treatment

CONTEXT

Prader-Willi syndrome (PWS) is a complex hypothalamic disorder, combining hyperphagia, hypotonia, intellectual disability, and pituitary hormone deficiencies. Annual mortality of patients with PWS is high (3%). In half of the patients, the cause of death is obesity related and/or of cardiopulmonary origin. Health problems leading to this increased mortality often remain undetected due to the complexity and rareness of the syndrome.

OBJECTIVE

To assess the prevalence of health problems in adults with PWS retrospectively.

PATIENTS, DESIGN, AND SETTING

We systematically screened 115 PWS adults for undiagnosed health problems. All patients visited the multidisciplinary outpatient clinic for rare endocrine syndromes at the Erasmus University Medical Center, Rotterdam, Netherlands. We collected the results of medical questionnaires, interviews, physical examinations, biochemical measurements, polygraphy, polysomnography, and radiology.

MAIN OUTCOME MEASURES

Presence or absence of endocrine and nonendocrine comorbidities in relation to living situation, body mass index, genotype, and demographic factors.

RESULTS

Seventy patients (61%) had undiagnosed health problems, while 1 in every 4 patients had multiple undiagnosed health problems simultaneously. All males and 93% of females had hypogonadism, 74% had scoliosis, 18% had hypertension, 19% had hypercholesterolemia, 17% had type 2 diabetes mellitus, and 17% had hypothyroidism. Unfavorable lifestyles were common: 22% exercised too little (according to PWS criteria) and 37% did not see a dietitian.

CONCLUSIONS

Systematic screening revealed many undiagnosed health problems in PWS adults. Based on patient characteristics, we provide an algorithm for diagnostics and treatment, with the aim to prevent early complications and reduce mortality in this vulnerable patient group.

Central Adrenal Insufficiency Is Rare in Adults With Prader-Willi Syndrome

CONTEXT

Prader-Willi syndrome (PWS) is associated with several hypothalamic-pituitary hormone deficiencies. There is no agreement on the prevalence of central adrenal insufficiency (CAI) in adults with PWS. In some countries, it is general practice to prescribe stress-dose hydrocortisone during physical or psychological stress in patients with PWS. Side effects of frequent hydrocortisone use are weight gain, osteoporosis, diabetes mellitus, and hypertension-already major problems in adults with PWS. However, undertreatment of CAI can cause significant morbidity-or even mortality.

OBJECTIVE

To prevent both over- and undertreatment with hydrocortisone, we assessed the prevalence of CAI in a large international cohort of adults with PWS. As the synacthen test shows variable results in PWS, we only use the metyrapone test (MTP) and insulin tolerance test (ITT).

DESIGN

Metyrapone test or ITT in adults with PWS (N = 82) and review of medical files for symptoms of hypocortisolism related to surgery (N = 645).

SETTING

Outpatient clinic.

PATIENTS OR OTHER PARTICIPANTS

Eighty-two adults with genetically confirmed PWS.

MAIN OUTCOME MEASURE

For MTP, 11-deoxycortisol > 230 nmol/L was considered sufficient. For ITT, cortisol > 500 nmol/L (Dutch, French, and Swedish patients) or > 450 nmol/L (British patients) was considered sufficient.

RESULTS

Central adrenal insufficiency was excluded in 81 of 82 patients. Among the 645 patients whose medical files were reviewed, 200 had undergone surgery without perioperative hydrocortisone treatment. None of them had displayed any features of hypocortisolism.

CONCLUSIONS

Central adrenal insufficiency is rare (1.2%) in adults with PWS. Based on these results, we recommend against routinely prescribing hydrocortisone stress-doses in adults with PWS.

Defining Mental and Behavioural Disorders in Genetically Determined Neurodevelopmental Syndromes with Particular Reference to Prader-Willi Syndrome

Genetically determined neurodevelopmental syndromes are frequently associated with a particular developmental trajectory, and with a cognitive profile and increased propensity to specific mental and behavioural disorders that are particular to, but not necessarily unique to the syndrome. How should these mental and behavioural disorders best be conceptualised given that similar symptoms are included in the definition of different mental disorders as listed in DSM-5 and ICD-10? In addition, a different conceptual framework, that of applied behavioural analysis, has been used to inform interventions for what are termed ‘challenging behaviours’ in contrast to types of interventions for those conditions meeting diagnostic criteria for a ‘mental disorder’. These syndrome-specific developmental profiles and associated co-morbidities must be a direct or indirect consequence of the genetic abnormality associated with that syndrome, but the genetic loci associated with the syndrome may not be involved in the aetiology of similar symptoms in the general population. This being so, should we expect underlying brain mechanisms and treatments for specific psychopathology in one group to be effective in the other? Using Prader-Willi syndrome as an example, we propose that the conceptual thinking that informed the development of the Research Domain Criteria provides a model for taxonomy of psychiatric and behavioural disorders in genetically determined neurodevelopmental syndromes. This model brings together diagnostic, psychological and developmental approaches with the aim of matching specific behaviours to identifiable neural mechanisms.

Profiles and trajectories of impaired social cognition in people with Prader-Willi syndrome

Introduction

People with Prader-Willi syndrome (PWS) have a distinctive behavioral phenotype that includes intellectual disability, compulsivity, inattention, inflexibility and insistence on sameness. Inflexibility and inattention are at odds with the cognitive flexibility and attention to social cues needed to accurately perceive the social world, and implicate problems in social cognition. This study assessed two social cognition domains in people with PWS; emotion recognition and social perception. We identified changes in social cognition over an approximate two-year time period (M = 2.23 years), relative strengths and weakness in social cognition, and correlates and predictors of social cognition.

Methods

Emotion recognition and social perception were examined at two time points in 94 individuals with PWS aged 5 to 62 years (M = 13.81, SD = 10.69). Tasks administered included: standardized IQ testing; parent-completed measures of inattention and inflexibility; standard emotion recognition photos (fear, sadness, anger, happy); and videotaped social perception vignettes depicting negative events with either sincere/benign or insincere/hostile interactions between peers.

Results

An atypical trajectory of negative emotion recognition emerged, marked by similar levels of poor performances across age, and confusion between sad and anger that is typically resolved in early childhood. Recognition of sad and fear were positively correlated with IQ. Participants made gains over time detecting social cues, but not in forming correct conclusions about the intentions of others. Accurately judging sincere intentions remained a significant weakness over time. Relative to sincere intentions, participant’s performed significantly better in detecting negative social cues, and correctly judging trickery, deceit and lying. Age, IQ, inattention, and recognition of happy and sad accounted for 29% of variance in social perception.

Conclusion

Many people with PWS have deficits in recognizing sad, anger and fear, and accurately perceiving the sincere intentions of other people. The impact of these deficits on social behavior and relationships need to be better understood.

Treatment of Children With GH in the United States and Europe: Long-Term Follow-Up From NordiNet® IOS and ANSWER Program

CONTEXT

Understanding real-world prescribing of GH may help improve treatment of eligible patients.

OBJECTIVE

Overall: to assess real-world effectiveness and safety of GH (Norditropin). This analysis: to compare clinical characteristics of GH-treated children in the United States and Europe.

DESIGN

The American Norditropin Studies: Web-Enabled Research Program (ANSWER; 2002 to 2016, United States) and the NordiNet International Outcome Study (NordiNet IOS; 2006 to 2016, Europe) were multicenter longitudinal observational cohort studies.

SETTING

Data were recorded in 207 (United States) and 469 (Europe) clinics.

PARTICIPANTS

Patients with GH deficiency, Turner syndrome, Noonan syndrome, idiopathic short stature, Prader-Willi syndrome, or born small for gestational age, who commenced GH treatment aged <18 years.

INTERVENTION

GH was prescribed by treating physicians according to local practice.

MAIN OUTCOMES MEASURES

Baseline data and drug doses were recorded. Data on effectiveness and safety were collected.

RESULTS

ANSWER had 19,847 patients in the full analysis set (FAS; patients with birthdate information and one or more GH prescription) and 12,660 in the effectiveness analysis set (EAS; GH-naive patients with valid baseline information). NordiNet IOS had 17,711 (FAS) and 11,967 (EAS). Boys accounted for 69% (ANSWER) and 57% (NordiNet IOS). Treatment start occurred later than optimal to improve growth. The proportion of boys treated was generally larger, children were older at treatment start, and GH doses were higher in the United States vs Europe. No new safety signals of concern were noted.

CONCLUSIONS

In most indications, more boys than girls were treated, and treatment started late. Earlier diagnosis of GH-related disorders is needed. The data support a favorable benefit-risk profile of GH therapy in children.

The Global Prader-Willi Syndrome Registry: Development, Launch, and Early Demographics

Advances in technologies offer new opportunities to collect and integrate data from a broad range of sources to advance the understanding of rare diseases and support the development of new treatments. Prader–Willi syndrome (PWS) is a rare, complex neurodevelopmental disorder, which has a variable and incompletely understood natural history. PWS is characterized by early failure to thrive, followed by the onset of excessive appetite (hyperphagia). Additional characteristics include multiple endocrine abnormalities, hypotonia, hypogonadism, sleep disturbances, a challenging neurobehavioral phenotype, and cognitive disability. The Foundation for Prader–Willi Research’s Global PWS Registry is one of more than twenty-five registries developed to date through the National Organization of Rare Disorders (NORD) IAMRARE Registry Program. The Registry consists of surveys covering general medical history, system-specific clinical complications, diet, medication and supplement use, as well as behavior, mental health, and social information. Information is primarily parent/caregiver entered. The platform is flexible and allows addition of new surveys, including updatable and longitudinal surveys. Launched in 2015, the PWS Registry has enrolled 1696 participants from 37 countries, with 23,550 surveys completed. This resource can improve the understanding of PWS natural history and support medical product development for PWS.

Prevalence of Mental Illness in Adolescents and Adults With Congenital Heart Disease from the Colorado Congenital Heart Defect Surveillance System

The aim of this study was to estimate the prevalence of the full spectrum of mental illness in adolescents (aged 11 to 17) and adults (aged 18 to 64) with congenital heart defects (CHDs) in the population-level Colorado Congenital Heart Disease Surveillance System. Further we sought to investigate whether severity of the defect, frequency of recent cardiac procedures or underlying genetic disorders influence these estimates. The cohort included patients in clinical care for CHDs between January 1, 2011 and December 31, 2013, identified across multiple healthcare systems and insurance claims. Of 2,192 adolescents with CHDs, 20% were diagnosed with a mental illness with the most prevalent categories being developmental disorders (8%), anxiety disorders (6%), attention, conduct, behavior, impulse control disorders (6%), and mood disorders (5%). Of 6,924 adults with CHDs, 33% were diagnosed with a mental illness with the most prevalent categories being mood disorders (13%), anxiety disorders (13%), and substance-related disorders (6%). Greater lesion complexity was associated with a higher likelihood of anxiety and developmental disorders in both adolescents and adults. Adolescents and adults who had ≥2 cardiac procedures in the 3-year surveillance period had a 3- and 4.5-fold higher likelihood of a mental illness diagnosis, respectively, compared with those who had fewer than 2 cardiac procedures. Finally, patients with a genetic syndrome were more likely to have a mental illness diagnosis. In conclusion, mental illness is a prevalent co-morbidity in the adolescent and adult population with CHDs, thus comprehensive care should include mental health care.

Brief Report: Challenging Behaviors in Toddlers and Preschoolers with Angelman, Prader-Willi, and Williams Syndromes

Children with neurogenetic syndromes (NGS) experience comorbid challenging behaviors and psychopathology. We examined challenging behaviors in 86 toddlers and preschoolers across three NGS [Angelman syndrome (AS), Prader-Willi syndrome (PWS), and Williams syndrome (WS)] and 43 low-risk controls (LRC), using the Child Behavior Checklist for Ages 1½-5. Challenging behavior profiles differed across NGS, with generally elevated behaviors in AS and WS, but not PWS, relative to LRC. Withdrawn and autism spectrum symptoms were particularly elevated in AS. Although several profiles were similar to those previously reported in older children and adults, we also observed inconsistencies that suggest non-linear developmental patterns of challenging behaviors. These findings underscore the importance of characterizing early challenging behaviors to inform atypical phenotypic development and targeted intervention.

Prevalence and risk factors for type 2 diabetes mellitus with Prader-Willi syndrome: a single center experience

BACKGROUND

Prader-Willi syndrome (PWS) is often related to severe obesity and type-2 diabetes mellitus (T2DM). However, few studies, and none in Korea, have examined prevalence of T2DM and other variables in PWS. The aim of this study was to identify the prevalence and associated risk factors for T2DM in Korean patients with PWS.

METHODS

We performed a retrospective cohort study of the 84 PWS patients aged 10 or over (10.3-35.8 years of age) diagnosed with PWS at Samsung Medical Center from 1994 to 2016. We estimated occurrence of T2DM according to age (10-18 years versus >18 years), body mass index (BMI), genotype, history of growth hormone therapy, homeostasis model of assessment-insulin resistance (HOMA-IR), and the presence of dyslipidemia, hypogonadism, or central precocious puberty. Additionally, we investigated cutoff values of risk factors for development of T2DM.

RESULTS

Twenty-nine of a total 211 patients, diagnosed with PWS over the study period, were diagnosed as having T2DM (13.7%, mean age 15.9 ± 3.6 years). In the >18 years group, obesity, HOMA-IR, and presence of dyslipidemia, hypogonadism, or central precocious puberty were associated with the occurrence of T2DM in univariate analysis. In multivariate logistic regression analysis, only obesity (p = 0.001) and HOMA-IR (p < 0.001) were significant predictive factors for T2DM. Based on the receiver operating a characteristic curve analysis, the cutoff values of HOMA-IR and BMI for predicting T2DM were >2.7 and >28.49 kg/m2, respectively. Of the 29 patients, seven had ≥1 microvascular complication, with non-proliferative diabetic retinopathy in 6 of 7 cases. Advanced age and HOMA-IR were positively correlated with diabetic microvascular complications (p < 0.05, Spearman correlation coefficient 0.393 and 0.434, respectively).

CONCLUSIONS

The prevalence of diabetes in Korean PWS was similar to that in previous results. BMI and HOMA-IR were strong predictive factors for the development of T2DM in PWS. We specifically suggest the regular monitoring of glucose homeostasis parameters through a detailed settlement of ethnically specific cutoff values for BMI and HOMA-IR in PWS to prevent progression of T2DM and diabetic microvascular complications.

[Psychosis in a patient with Prader-Willi syndrome]

Prader-Willi syndrome (pws) is a genetic disorder characterised by specific physical and behavioural abnormalities. Recent studies indicate that patients suffering from this syndrome have an increased risk of psychiatric disorders, including psychosis. We describe the development and the psychiatric condition of a 31-year-old patient with pws who had a first psychotic episode at age 14 and subsequently experienced a highly variable course of recovery and relapse.

Disorders of glucose metabolism in Prader-Willi syndrome: Results of a multicenter Italian cohort study

BACKGROUND AND AIMS

Prader-Willi syndrome (PWS) is characterized by a high incidence of altered glucose metabolism (AGM). However, epidemiological data on impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) are still discordant.

METHODS AND RESULTS

We performed a multicenter study based on 274 PWS patients [144 females, aged 20.3 ± 10.4 yrs (range: 8.1-50.1 years)] evaluating the prevalence for AGM in the entire group, and according to age (children <10 yrs; adolescents 10-18 yrs, and adults >18 yrs), Body Mass Index (BMI = kg/m(2)), gender, genotypes (deletion or uniparental disomy for chromosome 15), and GH therapy (GHT) (untreated, previously or currently treated). Altogether, AGM was detected in 67 (24.4%) of patients (0.7% IFG, 10.2% IGT, 13.5% T2DM). The prevalence of AGM was correlated to age (p = 0.001), BMI (p = 0.001) and HOMA-IR (p = 0.001). However, gender, genotype, and GHT did not influence AGM development in univariate analysis. These data were confirmed as positive predictors when inserted in a multivariate analysis model.

CONCLUSION

This study is the first report on the prevalence of AGM in a large population of PWS. Overall, PWS subjects show a high prevalence of AGM that appears more common in obese and adult subjects. Our data confirm the main role of obesity on the individual metabolic risk clustering in PWS, and thus reinforce the concept that improvement in weight control remains the most important goal of any PWS treatment program.

Medical, psychological and social features in a large cohort of adults with Prader-Willi syndrome: experience from a dedicated centre in France

BACKGROUND

Prader-Willi syndrome (PWS) is a developmental genetic disorder characterised by a variable expression of medical, cognitive and behavioural symptoms. In adulthood, the prevalence and severity of these symptoms determine the quality of life of the affected persons. Because of their rare disease condition, data on health and social problems in adults with PWS are scarce. In this research, we present medical, psychological and social features of a large cohort of adults admitted to a specialised PWS centre in France and analyse the differences according to genotype, gender and age.

METHODS

Data from 154 patients (68 men/86 women), with a median age of 27 years (range 16-54), were collected during their stay in our centre. Clinical histories were completed using information from parents or main caregivers, and the same medical team performed the diagnosis of different clinical conditions. Statistical analyses were performed to determine the influence of factors such as genotype, age or gender.

RESULTS

Paternal deletion genotype was the most frequent (65%) at all ages. Most patients had mild or moderate intellectual disability (87%). Only 30% had studied beyond primary school and 70% were in some special educational or working programme. Most of them lived in the family home (57%). The most prevalent somatic comorbidities were scoliosis (78%), respiratory problems (75%), dermatological lesions (50%), hyperlipidaemia (35%), hypothyroidism (26%), Type 2 diabetes mellitus (25%) and lymph oedema (22%). Some form of psychotropic treatment was prescribed in 58% of subjects, and sex hormones in 43%. Patients with deletion had a higher body mass index (44 vs. 38.9 kg/m(2)) and displayed higher frequency of sleep apnoeas. Non-deletion patients received insulin treatment (19% vs. 4%) and antipsychotic treatment (54.8% vs. 32.7%) more frequently. No difference was observed in the prevalence of Type 2 diabetes between the two genotype groups. Patients >27 years of age had a higher rate of comorbidities (Type 2 diabetes, hypertension, respiratory problems and lymph oedema). Gender differences were minor.

CONCLUSIONS

Adult patients with PWS showed high prevalence of comorbid health problems that need to be monitored for early treatment. Some of them are influenced by genotype and age. Another salient problem concerns the lack of adapted structures for better social integration. Further data about the real life and health conditions of adults with PWS are necessary to further our knowledge of the natural history of the disease and to design appropriate care strategies.

A longitudinal follow-up study of people with Prader-Willi syndrome with psychosis and those at increased risk of developing psychosis due to genetic subtype

BACKGROUND

People with Prader-Willi syndrome (PWS), a genetically defined developmental disorder, are at increased risk of developing psychotic illness. This is particularly the case for those with a genetic subtype of PWS called maternal uniparental disomy (mUPD), where rates of psychosis are more than 60% by early adult life. Little is known about the long-term course of their disorder.

METHOD

Individuals who had had episodes of psychosis or were at increased risk of developing psychosis due to their genetic subtype and had taken part in a previous study were contacted. Ten people were untraceable or deceased, leaving a total of 38 potential participants. Of these, 28 agreed to take part in a follow-up interview or complete a questionnaire about their mental health and medication. This represented 20/35 (57.1%) people from the original study who had had psychosis and 8/13 (61.5%) people who were at risk due to their genetic subtype. They were thought to be representative of those groups as a whole based on IQ and number of episodes of psychosis.

RESULTS

Two individuals had had recurrent episodes of psychosis while all others remained well. There were no new-onset cases of psychosis in those at risk. Individuals with PWS remained on high levels of psychiatric medication throughout the follow-up period.

CONCLUSIONS

Recurrent episodes of psychosis may be rare in people with PWS once stability has been achieved in the management of their illness. We speculate that this may be due to the protective influence of medication.

Prader Willi syndrome and obstructive sleep apnea: co-occurrence in the pediatric population

BACKGROUND

A high prevalence of obstructive sleep apnea (OSA) occurs in children with Prader-Willi syndrome (PWS). Yet, due in part to the relatively small samples previously used, the prevalence of OSA has varied greatly across studies. It is also unclear if factors such as age, gender, body mass index (BMI), or type of genetic imprinting are associated with increased risk for OSA among children with PWS.

OBJECTIVES

To evaluate the (a) prevalence of OSA, as well as narcolepsy, in pediatric populations diagnosed with PWS; (b) effects of age, gender, body mass index, and genetic imprinting on OSA severity; and (c) efficacy of adenotonsillectomy (AT) for decreasing OSA severity in this population.

METHODS

All studies assessing OSA among children with PWS through August 2013 were identified using the PubMed/Medline, Psych Info, Cochrane library, and Google Scholar data bases.

RESULTS

Fourteen studies of children diagnosed with PWS and who were assessed for OSA using polysomnography (PSG) met inclusion criteria (n = 224 children). The prevalence of OSA across studies was 79.91% (n = 179/224). Among youths with OSA, 53.07% had mild OSA, 22.35% moderate OSA, and 24.58% severe OSA. Narcolepsy was found to occur in 35.71% of children with PWS. Adenotonsillectomy was associated with improvement in OSA for most children with PWS. However, residual OSA was present in the majority of cases post-surgery.

CONCLUSION

This study confirms the high prevalence of OSA and narcolepsy among children with PWS. Screening for OSA and narcolepsy among children with PWS is recommended. In addition, while adenotonsillectomy was effective in reducing OSA for some children, alternative treatments may need to be considered, given the only moderate response rate.

Impaired theory of mind and symptoms of Autism Spectrum Disorder in children with Prader-Willi syndrome

In order to evaluate the social cognitive functioning in children with Prader-Willi syndrome (PWS), Theory of Mind (ToM) and symptoms of Autism Spectrum Disorder were evaluated. Sixty-six children with PWS aged 7-17 years were tested using the Theory of Mind test-R and the Diagnostic Interview for Social Communication disorders. We tested the correlation between Total ToM Standard Deviation Score (Total ToM SDS) and genetic subtype of paternal deletion or maternal uniparental disomy, and total IQ, verbal IQ and performal IQ. Prevalence and symptoms of Autism Spectrum Disorder were assessed. Median (interquartile range) of total ToM SDS of those aged 7-17 years was -3.84 (-5.73, -1.57). Their Total ToM SDS correlated with total IQ (β=0.662, p<0.001, adj.R(2)=0.407), in particular with verbal IQ (β=0.502, p=0.001, adj.R(2)=0.409), but not with performal IQ (β=0.241, p>0.05, adj.R(2)=0.259). No difference in Total ToM SDS was found between children with deletion and maternal uniparental disomy (β=-0.143, p>0.05, adj.R(2)=-0.016). Compared to the reference group of healthy children aged 7-12 years, children with PWS in the same age group had a median ToM developmental delay of 4 (3-5) years. One third of children with PWS scored positive for Autism Spectrum Disorder. Most prominent aberrations in Autism Spectrum Disorder were focused on maladaptive behavior. Our findings demonstrate a markedly reduced level of social cognitive functioning, which has consequences for the approach of children with PWS, i.e. adjustment to the child's level of social cognitive functioning.

Recent updates on recombinant human growth hormone outcomes and adverse events

PURPOSE OF REVIEW

To provide up-to-date information on outcomes and adverse events associated with the use of recombinant human growth hormone (rhGH). We will focus on patients with Prader Willi Syndrome and Idiopathic Short Stature. We will also discuss recent reports on long-term adverse events from the European database.

RECENT FINDINGS

Prader Willi Syndrome is associated with hypogonadism, which does not appear to be affected by treatment with rhGH. However, there is new evidence that treatment may improve cognition. For patients with Idiopathic Short Stature, the gain in near adult height with treatment with rhGH appears to be 3-4 cm. Although a recent analysis of this group shows that certain patient characteristics may help identify those most likely to have a good response to treatment. Additionally, the safety and appropriateness of growth hormone treatments in Europe study released preliminary data from patients treated in two separate locations that showed conflicting information on risk of mortality from treatment with rhGH.

SUMMARY

Although we will continue to receive new information regarding the safety and effects of treatment with rhGH, it is important to discuss the risks and benefits with our patients. Additionally, it is incumbent on us to help guide the treatment to those most likely to benefit.

The FSH-inhibin axis in prader-willi syndrome: heterogeneity of gonadal dysfunction

BACKGROUND

We characterized the spectrum and etiology of hypogonadism in a cohort of Prader-Willi syndrome (PWS) adolescents and adults.

METHODS

Reproductive hormonal profiles and physical examination were performed on 19 males and 16 females ages 16-34 years with PWS. Gonadotropins, sex-steroids, inhibin B (INB) and anti-Mullerian hormone (AMH) were measured. We defined 4 groups according to the relative contribution of central and gonadal dysfunction based on FSH and INB levels: Group A: primary hypogonadism (FSH >15 IU/l and undetectable INB (<10 pg/ml); Group B: central hypogonadism (FSH <0.5 IU/l, INB <10 pg/ml); Group C: partial gonadal & central dysfunction (FSH 1.5-15 IU/l, INB >20 pg/ml); Group D: mild central and severe gonadal dysfunction (FSH 1.5-15 IU/l, INB < 10 pg/ml.

RESULTS

There were 10, 8, 9 and 8 individuals in Groups A-D respectively; significantly more males in group A (9, 4, 4 and 2; P = 0.04). Significant differences between the groups were found in mean testosterone (P = 0.04), AMH (P = 0.003) and pubic hair (P = 0.04) in males and mean LH (P = 0.003) and breast development (P = 0.04) in females. Mean age, height, weight, BMI and the distribution of genetic subtypes were similar within the groups.

CONCLUSIONS

Analysis of FSH and inhibin B revealed four distinct phenotypes ranging from primary gonadal to central hypogonadism. Primary gonadal dysfunction was common, while severe gonadotropin deficiency was rare. Longitudinal studies are needed to verify whether the individual phenotypes are consistent.

Psychiatric illness in a cohort of adults with Prader-Willi syndrome

Previous studies have suggested an association between PWS and comorbid psychiatric illness. Data on prevalence rates of psychopathology is still scarce. This paper describes a large-scale, systematic study investigating the prevalence of psychiatric illness in a Dutch adult PWS cohort. One hundred and two individuals were screened for psychiatric illness. Case vignettes were written by the first author on 63 individuals with a positive screening on psychopathology according to the interviews, medical history, medication use and behavioural questionnaires. These case vignettes were rated by two psychiatrists specializing in intellectual disability (ID). Psychopathology was divided into four diagnostic categories: bipolar disorder with psychotic symptoms, psychotic illness, depressive illness with psychotic symptoms and depressive illness without psychotic symptoms. Nine out of 53 persons (17%) with a 15q11-13 deletion and 28 out of 44 (64%) persons with maternal uniparental disomy (mUPD) were diagnosed with a current or previous psychiatric illness. Depressive illness with psychotic symptoms was the cause of psychiatric problems in the majority of persons with PWS due to deletion (56%). In the case of mUPD, almost all individuals with histories of psychopathology suffered from psychotic symptoms (85%) with or without affective component. Psychiatric examination should be part of general management of adults with PWS, especially when caused by mUPD. More attention should be paid to the presence of precursor symptoms, indicating a developing psychiatric episode. Longitudinal studies are needed to gain more insight into the natural history of psychiatric illness in adults with PWS.

Duty of care and autonomy: how support workers managed the tension between protecting service users from risk and promoting their independence in a specialist group home

BACKGROUND

In the UK those paid to support adults with intellectual disabilities must manage two potentially conflicting duties that are set out in policy documents as being vital to their role: protecting service users (their duty of care) and recognising service users' autonomy. This study focuses specifically on the support of people with the genetically determined condition, Prader-Willi syndrome (PWS). Due to the behaviours associated with PWS, the support of this group of people vividly illustrates the tension between respect for autonomy and duty of care. This article explores how support workers working in a residential group home managed their competing duties of managing risk and promoting independence in practice.

METHODS

An ethnographic study, comprising of qualitative observations, semi-structured interviews and documentary analysis, was undertaken to investigate the work of support workers in a UK residential group home specialising in the support of adults diagnosed with PWS. The study focused on how support workers attempted to reconcile the tension between protecting service users from the risks associated with the syndrome and acknowledging service users' autonomy by enabling independence.

RESULTS

Findings demonstrate that risk was central to the structure of care delivery at the group home and support workers often adhered to standardised risk management procedures. The organisation also required support workers to promote service users' independence and many thought acknowledging service users' autonomy through the promotion of their independence was important. To manage tensions between their differing duties, some support workers deviated from standardised risk management procedures to allow service users a degree of independence.

CONCLUSIONS

There is a tension between the duty of care and the duty to recognise autonomy at the level of service delivery in residential homes. Support workers attempt to manage this tension; however, further work needs to be done by both residential services and policy makers to facilitate the reconciliation of the duty of care with the duty to recognise service users' autonomy in practice.

Pubarche and serum dehydroepiandrosterone sulphate levels in children with Prader-Willi syndrome

CONTEXT

Premature pubarche (PP) is reported in children with Prader-Willi Syndrome (PWS). Pubarche is preceded by adrenarche - an increase in serum levels of adrenal androgens, most specifically dehydroepiandrosterone sulphate (DHEAS).

OBJECTIVES

To assess DHEAS levels, the age at and progression of pubarche and the prevalence of PP in children with PWS.

DESIGN/PATIENTS

In the Dutch PWS Cohort Study, 120 children (6 months-17 years) are prospectively followed. Their age at onset of pubarche and various pubic hair stages and prevalence of PP were determined. Serum DHEAS levels were assessed in 97 children.

RESULTS

Median serum DHEAS levels were significantly higher in children with PWS than in healthy age-matched controls at ages 3-6 years (girls: P = 0·004 and boys: P = 0·010) and 6-10 years (girls: P = 0·045 and boys: P = 0·001). Age and gender significantly influenced DHEAS levels in children with PWS. The median [P10-P90] age at onset of pubarche in children with PWS was significantly younger than in healthy peers, 9·04[6·75-11·84] years in PWS girls (P < 0·0001) and 10·31 [8·65-12·29] years in PWS boys (P = 0·003). The prevalence of PP in children with PWS was 30·0% in girls and 16·1% in boys.

CONCLUSIONS

Compared to healthy children, children with PWS have significantly higher DHEAS levels from 3 to 10 years of age. They are younger at onset of pubarche and have a higher prevalence of premature pubarche. DHEAS levels in PWS are influenced by age and gender. Our findings indicate earlier maturation of the zona reticularis of the adrenal glands in children with PWS.

Care of the patient with Prader-Willi syndrome

Prader-Willi syndrome (PWS), a complex, neurodevelopmental genetic disorder with an estimated incidence of 7 in 10,000-29,000 people, is found in all races and both genders. It is the most commonly identified genetic cause of obesity. A multidisciplinary approach to managing PWS is highlighted, along with elements that should be included in a treatment plan, to help nurses deliver comprehensive care to meet the complex biopsychosocial needs of adults with PWS.

Behavioral phenotype in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is characterized by temper tantrums, impulsivity, mood fluctuations, difficulty with change in routine, skinpicking, stubbornness and aggression. Many studies on behavior in PWS are limited by sample size, age range, a lack of genetically confirmed diagnosis of PWS and inconsistent assessment of behavior. The aim of this study was to explore systematically the relation between behavioral problems and age groups, genetic subtypes and BMI categories in an adult PWS population. Participants were contacted via the Dutch Prader-Willi Parent Association and through physicians specialized in persons with ID. Behaviors were studied using the Developmental Behavior Checklist for Adults (DBC-A). The forms were completed by the main caregivers of 98 adults with a genetically confirmed diagnosis of PWS. Differences between age groups were statistically significant (ANOVA, p=0.03). DBC-A total scores were higher in the consecutive age groups, with the most behavioral problems in the oldest age groups. Differences between genetic subtypes were also statistically significant (ANOVA, p<0.01). Persons with mUPD had higher total scores on the DBC-A than persons with a deletion. Those with a Type I deletion showed higher total DBC-A scores than persons with a Type II deletion. There were no statistically significant differences in DBC-A total scores between the different BMI categories. Individuals with a BMI<25 had higher scores on the self-absorbed subscale compared to persons with a BMI between 25 and 30. Unlike previous descriptions of the behavioral phenotype in adults with PWS, we did not find a reduction in behavioral problems in older adults. Therefore, special attention should be paid to behavioral problems as part of general management of adults with PWS. Longitudinal studies are warranted to gain more insight into the natural history and course of behavioral problems in adults and older people with PWS over the long term and possible risk and preventive factors.

The prevalence and phenomenology of self-injurious and aggressive behaviour in genetic syndromes

BACKGROUND

Self-injurious and aggressive behaviours are reported as components of some behavioural phenotypes but there are few studies comparing across syndrome groups. In this study we examined the prevalence of these behaviours and the associated person characteristics in seven genetic syndromes.

METHODS

Questionnaire data on self-injury and aggression, mood, hyperactivity, autism spectrum disorder and repetitive behaviour were collected on Angelman (AS, n=104), Cornelia de Lange (CdLS, 101), Cri du Chat (CdCS, 58), Fragile X (FXS, 191), Lowe (LS, 56), Prader-Willi (PWS, 189) and Smith-Magenis (SMS, 42) syndromes.

RESULTS

A significantly higher prevalence of self-injury was evident in CdCS, CdLS, FXS, PWS, LS and SMS. The prevalence of aggression was significantly heightened in AS and SMS. Self-injury was associated with repetitive and impulsive behaviour in CdLS, FXS, PWS and LS. Impulsivity and overactivity were significantly higher in those showing aggression across all syndrome groups.

CONCLUSIONS

These data quantify the risk for self-injury and aggression in the syndromes studied with implications for early intervention. The associations between these behaviours and person characteristics both within and between syndromes warrant further research.

Sleep disturbances and behavioural problems in adults with Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) are at risk of sleep disturbances, such as excessive daytime sleepiness (EDS) and sleep apnoea, and behavioural problems. Sleep disturbances and their relationship with other variables had not been researched extensively in adults with PWS.

METHOD

Sleep disturbances and behavioural problems were investigated in adults with genetically confirmed PWS using standardised questionnaires. Results of adults with paternal deletion (n=45) were compared with those of adults with maternal uniparental disomy (n=33).

RESULTS

Eleven adults with PWS (i.e. 15%) had a current sleep problem, mostly night waking problems. Twenty-six adults with PWS (i.e. 33%) suffered from severe EDS. No differences in prevalence of sleep disturbances between genetic subtypes were found. Seventeen adults with deletion (i.e. 38%) and 17 adults with maternal uniparental disomy (i.e. 52%) had behavioural problems. No significant relationships were found between sleep disturbances and behavioural problems.

CONCLUSIONS

In adults with PWS, EDS is the most common type of sleep disturbance. Men and individuals with relative high body mass index are at increased risk for EDS. More research, aimed at developing a suitable screening instrument for sleep apnoea in adults with PWS, is necessary. Clinical implications of the findings are discussed.

Psychiatric features in children with genetic syndromes: toward functional phenotypes

Neurodevelopmental disorders with identified genetic etiologies present a unique opportunity to study gene-brain-behavior connections in child psychiatry. Parsing complex human behavior into dissociable components is facilitated by examining a relatively homogenous genetic population. As children with developmental delay carry a greater burden of mental illness than the general population, familiarity with the most common genetic disorders will serve practitioners seeing a general child population. In this article basic genetic testing and 11 of the most common genetic disorders are reviewed, including the evidence base for treatment. Based on their training in child development, family systems, and multimodal treatment, child psychiatrists are well positioned to integrate cognitive, behavioral, social, psychiatric, and physical phenotypes, with a focus on functional impairment.

Cardiovascular and metabolic risk profile and acylation-stimulating protein levels in children with Prader-Willi syndrome and effects of growth hormone treatment

CONTEXT

Reports on the cardiovascular and metabolic risk profile in children with Prader-Willi syndrome (PWS) and the effects of GH treatment are scarce. Acylation-stimulating protein (ASP) stimulates glucose uptake and triglyceride storage in adipose tissue.

OBJECTIVES

The aim was to study the metabolic and cardiovascular risk profile and ASP levels and to investigate the effects of GH treatment.

DESIGN

We conducted a randomized controlled GH trial. Infants and prepubertal children were assigned to receive GH (1 mg/m(2) . d) or to serve as controls for 12 and 24 months, respectively.

PATIENTS

Eighty-five children with PWS (mean +/- sd age of 4.9 +/- 3.0 yr) participated in the study.

MAIN OUTCOME MEASURES

We measured fat percentage (fat%) with dual-energy x-ray absorptiometry, blood pressure, fasting insulin and glucose levels, serum lipids, and ASP levels.

RESULTS

Mean +/- SD fat% was 28.4 +/- 6.2 in infants and 36.9 +/- 8.5 in prepubertal children. Fat% sd score (SDS) was above 2 SDS in 95% of prepubertal children. In addition, 63% of infants and 73% of prepubertal children demonstrated at least one cardiovascular risk factor, defined as hypertension or dyslipidemia. The metabolic syndrome was demonstrated in 5% of all children. Mean +/- sd baseline ASP was 107 +/- 45 nmol/liter (normal < 58 nmol/liter) and correlated with fat mass and TG levels. GH improved fat%SDS and the HDLc/LDLc ratio (P < 0.0001 and P = 0.04). GH had no effect on mean ASP levels in this population.

CONCLUSIONS

Many children with PWS had dyslipidemia and high ASP levels. GH improved fat% and high-density lipoprotein cholesterol/low-density lipoprotein cholesterol, but not ASP. High ASP levels may prevent complete normalization of fat%SDS during GH treatment but may contribute in keeping glucose and insulin levels within normal range.

Pediatric otorhinolaryngologic manifestations of endocrinological pathologies

OBJECTIVE

Aim of the present review is to offer a concise but complete discussion about pathologies with pediatric otorhinolaryngological interest recognizing: (i) growth disorders, (ii) chromosomal disorders, and (iii) tumors.

METHODS

Pathologies characterized by a growth anomaly have been grouped, underlining the characteristics of otorhinolaryngological interest. Numerous syndromes typical of the pediatric age have been reported and classified according to the ailments of the orofacial district. Tumoral pathologies, for which the otorhinolaryngological operation is fundamental, have been descripted. We reviewed recent literature and older papers. We did not find recent literature regarding otorhinolaryngological features related to some of the pathologies described.

RESULTS/CONCLUSIONS

Otorhinolaryngologists should be familiar with pediatric disorders, since many of them have head and neck manifestations. This knowledge allows to treat them with a correct surgical approach, in order to implore children's quality of life.

Sleep disordered breathing in infants with Prader-Willi syndrome during the first 6 weeks of growth hormone therapy: a pilot study

BACKGROUND

Sleep-related breathing disorders are common in individuals with Prader-Willi syndrome (PWS). The US Food and Drug Administration approved the use of growth hormone in PWS in 2000. Many infants with PWS are being started on growth hormone therapy, but no data exist on the respiratory effects of growth hormone treatment in this age group.

STUDY OBJECTIVES

To perform overnight polysomnographic studies to evaluate the effects of growth hormone on sleep-related breathing in infants with PWS.

METHODS

Pilot study evaluating overnight polysomnography before and 6 weeks after initiation of growth hormone therapy at a dose of 1 mg/m2 per day in 20 infants from 2 to 21 months of age with genetically confirmed PWS. Polysomnography results were analyzed for frequency and severity of obstructive and central apnea and hypopnea events and the overall apnea-hypopnea index.

RESULTS

When data were analyzed for the total group, there were no significant changes in sleep-related disorders before and after institution of growth hormone therapy. However, 12 infants had an increase in the frequency of obstructive events associated with either upper respiratory infections or a diagnosis of gastroesophageal reflux at the second sleep study (after institution of growth hormone therapy). Resolution of these conditions was associated with normalization of polysomnography results on follow-up studies.

CONCLUSIONS

Overall, growth hormone therapy, per se, had no significant effect on sleep related-breathing disorders in infants with PWS. Infants with upper respiratory infections of gastroesophageal reflux may be at risk for developing more obstructive events after beginning growth hormone treatment. We recommend close monitoring of infants with PWS after they begin growth hormone therapy, especially when they have upper respiratory infections.

The relationship between central adrenal insufficiency and sleep-related breathing disorders in children with Prader-Willi syndrome

BACKGROUND

The annual death rate of patients with Prader-Willi syndrome (PWS) is high (3%). Many deaths of children are sudden and unexplained. Sleep apneas have been suggested to play a role in sudden deaths. Recently, we discovered that 60% of patients with PWS suffer from central adrenal insufficiency (CAI) during stress.

OBJECTIVE

The aim was to study the relationship between CAI and sleep-related breathing disorders.

DESIGN

In 20 children with PWS who underwent a metyrapone test (30 mg/kg at 2330 h), sleep-related breathing was evaluated by polysomnography before the metyrapone test. In addition, we recorded sleep-related breathing in 10 children with PWS during their metyrapone test. CAI was diagnosed when ACTH levels during the metyrapone test were below 33 pmol/liter at 0730 h. All tests were performed during healthy condition.

SETTING

The study was conducted in a pediatric intensive care unit and specialized sleep center.

RESULTS

Median (interquartile range) age was 8.4 yr (6.5-10.2). After metyrapone administration, median (interquartile range) central apnea index (number/hour) increased significantly from 2.2 (0.4-4.7) to 5.2 (1.5-7.9) (P = 0.007). The increase tended to be higher in children with CAI [2.8 (2.0-3.9) vs. 1.0 (-0.2 to 2.6); P = 0.09]. During polysomnography before the metyrapone test, sleep-related breathing was worse in children with CAI, who had a significantly higher central apnea index and tended to have a lower minimum oxygen saturation compared to those without CAI (P = 0.03 and P = 0.07).

CONCLUSIONS

In children with PWS, the central apnea index increased significantly after metyrapone administration, particularly in those with CAI during stress. In addition, children with CAI had a higher central apnea index compared to those without several months before the metyrapone test.

The European Prader-Willi Syndrome Clinical Research Database: an aid in the investigation of a rare genetically determined neurodevelopmental disorder

BACKGROUND

Prader-Willi Syndrome (PWS) is a rare genetically determined neurodevelopmental disorder with a complex phenotype that changes with age. The rarity of the syndrome and the need to control for different variables such as genetic sub-type, age and gender limits clinical studies of sufficient size in any one country. A clinical research database has been established to structure data collection and to enable multinational investigations into the development of children and adults with PWS.

METHODS

As part of a joint basic science and clinical study of PWS funded through Framework 6 of the European Union (EU), an expert multidisciplinary group was established that included clinicians involved in PWS research and clinical practice, expert database software developers, and representatives from two national PWS Associations. This group identified the key issues that required resolution and the data fields necessary for a comprehensive database to support PWS research.

RESULTS

The database consists of six 'index' entry points and branching panels and sub-panels and over 1200 data 'fields'. It is Internet-based and designed to support multi-site clinical research in PWS. An algorithm ensures that participant data are anonymous. Access to data is controlled in a manner that is compatible with EU and national laws. The database determines the assessments to be used to collect data thereby enabling the combining of data from different groups under specifically agreed conditions. The data collected at any one time will be determined by individual research groups, who retain control of the data. Over time the database will accumulate data on participants with PWS that will support future research by avoiding the need for repeat data collection of fixed data and it will also enable longitudinal studies and treatment trials.

CONCLUSION

The development of the database has proved to be complex with various administrative and ethical issues to be addressed. At an early stage, it was important to clarify the exact function of the database. It was agreed that it was primarily to support grant-funded research rather than clinical practice. The most complex issues that had to be addressed were concerned with data ownership and establishing the rules for data entry, retrieval and sharing that are compatible with data protection laws, and which are likely to be acceptable to participants and their families and to individual research groups.

Relationship between the IQ of people with Prader-Willi syndrome and that of their siblings: evidence for imprinted gene effects

BACKGROUND

Genetic disorders occasionally provide the means to uncover potential mechanisms linking gene expression and physical or cognitive characteristics or behaviour. Prader-Willi syndrome (PWS) is one such genetic disorder in which differences between the two main genetic subtypes have been documented (e.g. higher verbal IQ in one vs. higher performance IQ in the other; slower than normal reaction time in one vs. normal in the other). In a population study of PWS, the IQ distribution of people with PWS was approximately normal. This raises the question of whether this distribution arose from a systematic effect of PWS on IQ (hypothesis 1) or whether it was the fortuitous result of random effects (hypothesis 2).

METHOD

The correlation between PWS and sibling IQ was determined in order to discriminate between the two hypotheses. In the first case we would expect the correlation to be similar to that found in the general population (0.5); in the second case it would be zero.

RESULTS

It was found that the overall PWS-sibling IQ correlation was 0.3 but that the two main genetic subtypes of PWS differed in their familial IQ relationships. As expected, the IQs of normal siblings correlated 0.5, and this was also the case with one genetic subtype of PWS (uniparental disomy) and their siblings, while the other subtype IQ correlated -0.07 with sibling IQ.

CONCLUSIONS

This is a potentially powerful result that gives another clue to the role of genes on chromosome 15 in the determination of IQ. It is another systematic difference between the genetic subtypes of PWS, which needs an explanation in terms of the very small genetic differences between them.

[Myopia in systemic disorders]

Myopia is the most common refractive error Myopia has been well established as a multifactorial disease with both genetic and environmental etiology. A number of genetic loci have been linked with myopia. We have described the prevalence and the symptoms of systemic disorders associated with myopia, including: Stickler syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Weill-Marchesani syndrome, homocystinuria, McCune-Albright syndrome, Kniest syndrome, Down syndrome, Prader-Willi syndrome, Noonan syndrome, Cohen syndrome, Rubinstein-Taybi syndrome, Cornelia de Lange syndrome and fetal alcohol syndrome.

The phenomenology and diagnosis of psychiatric illness in people with Prader-Willi syndrome

BACKGROUND

Psychotic illness is strongly associated with the maternal uniparental disomy (mUPD) genetic subtype of Prader-Willi syndrome (PWS), but not the deletion subtype (delPWS). This study investigates the clinical features of psychiatric illness associated with PWS. We consider possible genetic and other mechanisms that may be responsible for the development of psychotic illness, predominantly in those with mUPD.

METHOD

The study sample comprised 119 individuals with genetically confirmed PWS, of whom 46 had a history of psychiatric illness. A detailed clinical and family psychiatric history was obtained from these 46 using the PAS-ADD, OPCRIT, Family History and Life Events Questionnaires.

RESULTS

Individuals with mUPD had a higher rate of psychiatric illness than those with delPWS (22/34 v. 24/85, p<0.001). The profile of psychiatric illness in both genetic subtypes resembled an atypical affective disorder with or without psychotic symptoms. Those with delPWS were more likely to have developed a non-psychotic depressive illness (p=0.005) and those with mUPD a bipolar disorder with psychotic symptoms (p=0.00005). Individuals with delPWS and psychotic illness had an increased family history of affective disorder. This was confined exclusively to their mothers.

CONCLUSIONS

Psychiatric illness in PWS is predominately affective with atypical features. The prevalence and possibly the severity of illness are greater in those with mUPD. We present a 'two-hit' hypothesis, involving imprinted genes on chromosome 15, for the development of affective psychosis in people with PWS, regardless of genetic subtype.

Cross-cultural comparisons of obesity and growth in Prader-Willi syndrome

Introduction The present study reports cross-cultural comparisons of body mass index (BMI) and growth in Prader-Willi syndrome, a neurodevelopmental disorder associated with obesity, growth restriction and mild learning disability. Our objectives were to: (1) compare rates of obesity in adults with Prader-Willi syndrome (PWS) in France, with data available from Belgium, the UK and the USA; (2) compare growth of French children with PWS with their counterparts in Germany and the USA; and (3) evaluate the contribution of genetic, medical and social parameters to obesity outcome in French children and adults with PWS. Method (1) Cross-sectional comparison of BMI of 40 French adults, 38 Belgian adults, 46 British adults and 292 North American adults; (2) Construction of growth curves for French children aged 2-20 years from longitudinal data for 150 individuals with PWS, and comparison with published growth curves from Germany and the USA; and (3) Longitudinal regression analysis of 141 French children and adults to determine the factors contributing to obesity outcome. Results A total of 82.5% French adults with PWS have BMI > 30 compared with 65.8% in Belgium (n.s.), 58.2% in the USA (P < 0.005), and 54.3% in the UK (P < 0.01). Higher rates of obesity in females vs. males were found in the USA sample (P < 0.001) but not in the other samples. In contrast to adults, growth curves for French children with PWS show similar rates of growth compared with children with PWS in Germany and the USA. The principal determining factors of BMI status in the French PWS population are age (P < 0.0001), cohort (born within the last 15 years vs. born over 15 years ago, P < 0.0002) and growth hormone replacement therapy (P < 0.0002). Significant subsidiary effects include domestic situation (P < 0.0001), genetic diagnosis (P < 0.0001) and age of diagnosis (P < 0.0001). Conclusions French adults with PWS have significantly higher rates of obesity than adults in the UK and the USA, but growth in French children with PWS is similar to the USA and Germany. Clinical management has a greater impact on obesity outcome in PWS than cultural factors.

Sleepiness and sleep disordered breathing in Prader-Willi syndrome: relationship to genotype, growth hormone therapy, and body composition

STUDY OBJECTIVES

Patients with Prader-Willi syndrome (PWS) suffer from excessive sleepiness and sleep disordered breathing (SDB). We reviewed the polysomnograms (PSGs) and multiple sleep latency tests (MSLTs) in a cohort of PWS patients to determine the relationship of BMI(Z) scores, daytime sleepiness, growth hormone (GH) treatments, and SDB.

METHODS

Attended overnight PSGs were performed for PWS patients referred for concern for SDB between January 2000 and January 2005. Age at time of study, genotype, use and dose of GH, sleepiness scale, normalized body-mass index (BMI(Z)), total sleep time, latency to stage I and REM sleep, sleep stage percentages, apnea-hypopnea index (AHI), central apnea (CA) frequency, oxygen saturation nadir, maximum carbon dioxide tension, periodic limb movement index, presence of snoring, normality of EEG, and, in several patients, mean sleep latency testing were determined.

RESULTS

All patients exhibited some form of SDB. There was a positive correlation between the BMI(Z) and AHI. The BMI(Z) was significantly different between GH-treated and -untreated groups, but there was not a significant difference between AHI, CA, oxygen nadir, or maximum carbon dioxide tension of the GH-treated and -untreated groups. There was no significant correlation between the MSLT and the sleepiness scale or AHI. There was also no significant difference between the AHIs of patients with different genetic defects.

CONCLUSIONS

There should be a low threshold for obtaining PSG to evaluate SDB, but the type and severity of SDB were not predictable based on a sleepiness scale score, BMI(Z), or underlying genetic defect.