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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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

[This corrects the article DOI: 10.3389/fendo.2023.1168648.].

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.

Systemic immune profile in Prader-Willi syndrome: elevated matrix metalloproteinase and myeloperoxidase and reduced macrophage inhibitory factor

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental syndrome with highly increased risk of obesity and cardiovascular disease (CVD). Recent evidence suggests that inflammation is implicated in the pathogenesis. Here we investigated CVD related immune markers to shed light on pathogenetic mechanisms.

METHODS

We performed a cross-sectional study with 22 participants with PWS and 22 healthy controls (HC), and compared levels of 21 inflammatory markers that reflect activity in different aspects of CVD related immune pathways and analyzed their association with clinical CVD risk factors.

RESULTS

Serum levels of matrix metalloproteinase 9 (MMP-9) was (median (range)) 121 (182) ng/ml in PWS versus 44 (51) ng/ml in HC, p = 1 × 10^-9), myeloperoxidase (MPO) was 183 (696) ng/ml versus 65 (180) ng/ml, p = 1 × 10^-5) and macrophage inhibitory factor (MIF) was 46 (150) ng/ml versus 121 (163) ng/ml (p = 1 × 10^-3), after adjusting for age and sex. Also other markers tended to be elevated (OPG, sIL2RA, CHI3L1, VEGF) but not significantly after Bonferroni correction (p > 0.002). As expected PWS had higher body mass index, waist circumference, leptin, C-reactive protein, glycosylated hemoglobin (HbA1c), VAI and cholesterol, but MMP-9, MPO and MIF remained significantly different in PWS after adjustment for these clinical CVD risk factors.

CONCLUSION

PWS had elevated levels of MMP-9 and MPO and of reduced levels of MIF, which were not secondary to comorbid CVD risk factors. This immune profile suggests enhanced monocyte/neutrophil activation, impaired macrophage inhibition with enhanced extracellular matrix remodeling. These findings warrant further studies targeting these immune pathways in PWS.

Distinct lipids profiles and associations with clinical indicators and gut microbiota in Prader-Willi syndrome children

Lipid metabolism is tightly linked to adiposity. Prader-Willi syndrome (PWS) is a typical genetic disorder caused obesity, however, the distinct lipidomic profiles in PWS children have not been thoroughly investigated. Herein, serum lipidomics analysis were simultaneously explored in PWS, simple obesity (SO) and normal children (Normal). Results indicated that the total concentration of phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) in PWS group were significantly deceased in comparison with both SO and Normal group. In contrast, compared with Normal group, there was an overall significantly increase on TAG level in both PWS and SO groups, with the highest was found in SO group. 39 and 50 differential lipid species were screened among three groups, and between obesity (PWS and SO) and Normal group, respectively. Correlation analysis revealed distinct profiles in PWS that different from other two groups. Notably, PC(P16:0/18:1), PE(P18:0-20:3), PE(P18:0-20:4)) showed significant negative correlation with Body mass index (BMI) soly in PWS groups. As for PE(P16:0-18:2), it showed negative association with BMI and weight in PWS group, but significant positive correlation in SO group, no statistical significant association were found in Normal group. We also found a significantly negative correlation between Blautia genus abundance and several significantly changed lipids, including LPC(14:0), LPC(16:0), TAG(C50:2/C51:9), TAG(C52:2/C53:9), TAG(C52:3/C53:10) and TAG(C52:4/C53:11), but no significant correlation in Normal group and SO group. Similarly, in PWS group, Neisseria genus was significantly negatively associated with CAR(14:1), CAR(18:0), PE(P18:0/20:3) and PE(P18:0/20:4), and extremely positively associated with TAG(C52:2/C53:9), while no obvious correlations were observed in Normal group and SO group.

CD16+ monocytes are involved in the hyper-inflammatory state of Prader-Willi Syndrome by single-cell transcriptomic analysis

Background

Patients with Prader-Willi syndrome (PWS) have a reduced life expectancy due to inflammation-related disease including cardiovascular disease and diabetes. Abnormal activation of peripheral immune system is postulated as a contributor. However, detailed features of the peripheral immune cells in PWS have not been fully elucidated.

Methods

Serum inflammatory cytokines were measured in healthy controls (n=13) and PWS patients (n=10) using a 65- multiplex cytokine assays. Changes of the peripheral immune cells in PWS was assessed by single-cell RNA sequencing (scRNA-seq) and high-dimensional mass cytometry (CyTOF) using peripheral blood mononuclear cells (PBMCs) from PWS patients (n=6) and healthy controls (n=12).

Results

PWS patients exhibited hyper-inflammatory signatures in PBMCs and monocytes were the most pronounced. Most inflammatory serum cytokines were increased in PWS, including IL-1β, IL-2R, IL-12p70, and TNF-α. The characteristics of monocytes evaluated by scRNA-seq and CyTOF showed that CD16⁺ monocytes were significantly increased in PWS patients. Functional pathway analysis revealed that CD16⁺ monocytes upregulated pathways in PWS were closely associated with TNF/IL-1β- driven inflammation signaling. The CellChat analysis identified CD16⁺ monocytes transmitted chemokine and cytokine signaling to drive inflammatory process in other cell types. Finally, we explored the PWS deletion region 15q11-q13 might be responsible for elevated levels of inflammation in the peripheral immune system.

Conclusion

The study highlights that CD16⁺ monocytes contributor to the hyper-inflammatory state of PWS which provides potential targets for immunotherapy in the future and expands our knowledge of peripheral immune cells in PWS at the single cell level for the first time.

Interference effect of food and emotional stimuli in Stroop-like tasks for children and adults with Prader-Willi Syndrome

Interference effect of food and emotional stimuli in Stroop-like tasks for children and adults with Prader-Willi Syndrome. The aim of this work was to study the way items related to food or emotion are processed by a population known to have difficulties with dietary restriction, namely individuals with Prader-Willi Syndrome (PWS). Given the presence of intellectual disability (ID) in PWS, our experiments were designed to examine whether these difficulties were specific to PWS or linked with their ID. Two modified Stroop tasks (i.e., a food version and an emotional version) were administered to seventy-four children (aged between 6 and 16 years old) divided into three groups (one with PWS, one with ID matched on age and Intellectual Quotient (IQ), and one healthy group matched on age) and to eighty-four adults (aged between 18 and 48 years old) distributed in the same three groups. For both tasks, a picture version was used for the children and a word version for the adults. For the food Stroop task, (Experiment 1), materials were composed of low or high-caloric food items and stimuli not related to food. The results show a food Stroop effect for children and adults with PWS that was absent in the group of healthy participants. Moreover, a food Stroop effect was also significant for adults with ID. For the emotional Stroop task (Experiment 2), materials were composed of negative, positive and neutral stimuli. The emotional Stroop effect was also obtained for children and adults with PWS as well as for the healthy group, but not for the age- and IQ-matched group. For the PWS groups, results show a preservation to process positive pictures for children and difficulties to process negative stimuli for both age-groups. These results suggest that people with PWS have difficulties in disengaging their attention when food stimuli are present in their environment and poorer abilities to process negative ones. These difficulties endure in adulthood.

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

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

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.

Intervention Response by Genetic Subtype: PRETEND-Preschool Program for Children with Prader-Willi Syndrome via Remote Parent Training

Prader-Willi Syndrome (PWS) is a rare neurodevelopmental disorder associated with social cognitive challenges, and pretend play has been demonstrated as a tool to achieve developmental goals. Following previous report on feasibility and acceptability of a remote, play-based parent-training program (Zyga, Russ, & Dimitropoulos, 2018), we now report on preliminary efficacy of this program to enhance pretend play skills and social cognitive skills in preschoolers with PWS. Results across two studies demonstrated efficacy when live-coaching play sessions incorporated children into the intervention. Increases in play skills were observed for children with the mUPD subtype of PWS who underwent intervention, compared with children with mUPD who were waitlisted. Children with DEL subtype were less likely to respond to intervention. Implications for results are discussed.

Relationship Between Sensory Processing and Autism Spectrum Disorder-Like Behaviors in Prader-Willi Syndrome

The relationship between sensory processing and ASD-like and associated behaviors in patients with Prader-Willi Syndrome (PWS) remains relatively unexplored. Examining this relationship, 51 adults with PWS were administered the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS), Short Sensory Profile (SSP-J), Food-Related Problem Questionnaire (FRPQ), and Aberrant Behavior Checklist (ABC-J). Based on SSP-J z-scores, participants were classified into three severity groups. Analysis of variance was performed to compare the behavioral scores of these three groups. Statistically significant group differences were observed in PARS (p = .006, ηp2 = .194) and ABC-J (p = .006, ηp2 = .193) scores. Our findings suggest that the level of sensory processing may predict ASD-like and aberrant behaviors in adults with PWS, implying the importance of a proper assessment for early intervention.

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.

An adapted scale to evaluate insight in Prader-Willi Syndrome

OBJECTIVE

To develop an insight scale for Prader-Willi Syndrome (PWS), a genetically determined neurodevelopmental disorder with different psychopathological and behavioural problems.

METHODOLOGY

A sample of 36 PWS patients (58.3% women) attended at the Endocrinological Department of the Corporació Sanitària Parc Taulí (Sabadell, Barcelona) was evaluated. Insight was assessed by means of an adapted version of the Scale of Unawareness of Mental Disorder (SUMD), including three general insight dimensions: awareness of having a PWS, awareness of the effects of psychopharmacological medication and awareness of the social consequences, as well as three items that assess awareness of each particular symptom of the disease (obesity/overweight, excessive appetite and excessive food intake).

RESULTS

The final Scale included six items and demonstrated an adequate internal consistency (Cronbach Alfa of 0.857 for Caregivers and 0.798 for Clinicians) but a high inter-rate variability. External validation using an Analytical-Visual Insight Scale was adequate.

CONCLUSIONS

The Adapted version for Prader-Willi patients of the Scale of Unawareness of Mental Disorder (APW-SUD) showed adequate psychometric properties and it is an easy to administer means to assess insight in this population.

Study of the deficit in planning abilities of adults with Prader-Willi Syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a complex developmental genetic disorder associated with intellectual disability and deficits in executive functions which result in disorganisation and poor personal autonomy.

AIMS

This study aimed to determine impairments in planning skills of adults with PWS, in relation with their intellectual disabilities, as well as the influence of food compulsions on their performance.

METHODS AND PROCEDURES

A modified version of the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome was used in three groups: a group of adults with PWS in comparison with two groups both matched on chronological age, one with typical development (TD) and one with intellectual disability (ID).

OUTCOMES AND RESULTS

Compared to TD adults, both adults with PWS and ID showed increased planning time and lower raw scores on the planning task. The execution time and the number of errors were higher in the PWS group compared to the comparison groups. All three groups performed worse in the non-food condition only for number of errors and raw score.

CONCLUSIONS AND IMPLICATIONS

Planning abilities were impaired in PWS adults. Results also showed that intellectual level plays a role in participants' performance. These findings are essential to understand the difficulties of people with PWS daily life.

Hypothalamic neuropeptides and neurocircuitries in Prader Willi syndrome

Prader-Willi Syndrome (PWS) is a rare and incurable congenital neurodevelopmental disorder, resulting from the absence of expression of a group of genes on the paternally acquired chromosome 15q11-q13. Phenotypical characteristics of PWS include infantile hypotonia, short stature, incomplete pubertal development, hyperphagia and morbid obesity. Hypothalamic dysfunction in controlling body weight and food intake is a hallmark of PWS. Neuroimaging studies have demonstrated that PWS subjects have abnormal neurocircuitry engaged in the hedonic and physiological control of feeding behavior. This is translated into diminished production of hypothalamic effector peptides which are responsible for the coordination of energy homeostasis and satiety. So far, studies with animal models for PWS and with human post-mortem hypothalamic specimens demonstrated changes particularly in the infundibular and the paraventricular nuclei of the hypothalamus, both in orexigenic and anorexigenic neural populations. Moreover, many PWS patients have a severe endocrine dysfunction, e.g. central hypogonadism and/or growth hormone deficiency, which may contribute to the development of increased fat mass, especially if left untreated. Additionally, the role of non-neuronal cells, such as astrocytes and microglia in the hypothalamic dysregulation in PWS is yet to be determined. Notably, microglial activation is persistently present in non-genetic obesity. To what extent microglia, and other glial cells, are affected in PWS is poorly understood. The elucidation of the hypothalamic dysfunction in PWS could prove to be a key feature of rational therapeutic management in this syndrome. This review aims to examine the evidence for hypothalamic dysfunction, both at the neuropeptidergic and circuitry levels, and its correlation with the pathophysiology of PWS.

[Prader-Willi and Angelman syndromes: case series diagnosed by MS-MLPA assay]

BACKGROUND

Prader Willi syndrome (PWS) and Angelman syndrome (AS) are neurodevelopmental disorders caused by deletions or methylation defects, making a loss of expression of imprinted genes located in the 15q11-q13 region, and these can be assessed by different cytogenomic and molecular techniques. We report a case series of patients with PWS and AS evaluated through the MS-MLPA assay.

CLINICAL CASES

We studied four patients with a clinical diagnosis of PWS and another with AS, evaluated as far as possible with karyotype and FISH, and with MS-MLPA assay for the 15q11-q13 region in all cases. In patients with PWS, neonatal hypotonia was the main reason for consultation and in three of them we identified a deletion of 15q11-q13 by MS-MLPA, also confirmed by FISH; and in the other one, an abnormal methylation pattern consistent with a maternal uniparental disomy. The patient with AS presented with a typical picture which led to the identification of a deletion in 15q11-q13 by MS-MLPA, also confirmed by FISH.

CONCLUSIONS

The use of the MS-MLPA assay for the 15q11-q13 region was very useful for the diagnosis and identification of the genomic and epigenetic defects involved in either PWS and AS.

[Epigenetics of Prader-Willi Syndrome: A good example of translational medicine]

In this editorial the author presents a study, concerning Prader-Willi syndrome, which is paradigmatic for translational medicine, given that it creates a synergy between genetics and molecular biology, in order to improve the care for patients suffering from this syndrome.

Multidimensional Evaluation of Awareness in Prader-Willi Syndrome

There are no studies about insight or awareness of illness in patients with Prader-Willi Syndrome (PWS). The objective of this study was to explore the level of awareness of the disorder, of the need for medication, and of the social consequences of the disease, as well as of its main symptoms in PWS. We also aimed to explore relationships between awareness and sociodemographic and clinical characteristics, and to compare all data with a matched sample of patients with psychosis. Insight was assessed by an Adapted version of the Scale of Unawareness of Mental Disorder in a cross-sectional pilot study at a University Hospital. Thirty-six individuals with PWS (58.3% women) were included. Results showed that PWS patients had a good awareness of the illness and of the effects of medication, in contrast to a lack of awareness of illness' social consequences. Awareness of obesity/overweight was excellent, as was the awareness of excessive appetite. Awareness of excessive food intake was only mild. Insight correlated with age and functionality, but not with BMI. PWS patients showed a better insight into the illness but a similar awareness of the effects of the medication and of the social consequences of the disease as compared to schizophrenia-spectrum patients. This profile of insight may have relevant clinical implications.

Growth Hormone Treatment for Prader-Willi Syndrome

The European Marketing Authorization for recombinant human growth hormone (rhGH) in children with Prader-Willi syndrome was the first indication for metabolic and body composition effects in children. In the US it is indicated for short stature associated with PWS. Recombinant hGH is the first treatment for the PWS population and radically changed the care of these children by facilitating access to physicians who prescribe rhGH, mainly paediatric endocrinologists, and manage the organization of multidisciplinary care. Recombinant hGH treatment improved linear growth, body composition, and socialization not only in children but also in young adults. The pathophysiology of combined hormonal deficiencies including GH is starting to be unravelled. We now have to focus on co-morbidities that are not modified by rhGH treatment, such as feeding disorders and behaviour problems, to truly change the life of patients. The transition of care from adolescents to young adults also remains a challenge.

Cycloid Psychosis Comorbid with Prader-Willi Syndrome: A Case Series

Psychosis is a relatively common psychiatric phenomenon seen in patients with Prader-Willi Syndrome (PWS). However, the presentation is atypical and difficult to classify within currently defined affective or psychotic disorders. This distinct presentation may be better understood as a phenomenon called "cycloid psychosis," described as an episodic psychosis with rapid full recovery between episodes. This study retrospectively analyzed the cases of 12 patients with genetically confirmed PWS who presented to an ambulatory psychiatric center for a change in behavior consistent with psychosis. Each case was then assessed for symptoms of cycloid psychosis, bipolar disorder, depression with psychotic features, schizophrenia, and schizoaffective disorder. Out of the 12 patients, 11 (91.7%) met the currently described diagnostic criteria for cycloid psychosis. Of the 12 patients, 7 (58.3%) also met the diagnostic criteria for bipolar disorder, and 1 (8.3%) also met the diagnostic criteria for schizoaffective disorder. None of the patients met the criteria for schizophrenia or depression with psychotic features. The findings in this study suggest that cycloid psychosis and bipolar disorder may both be comorbid with PWS. Psychiatric comorbidities in patients with PWS are atypical and clinicians should be aware of conditions such as cycloid psychosis when managing this vulnerable population.

Thinking outside the box: cataplexy without narcolepsy

Cataplexy is a transient loss of muscle tone that can be triggered by emotions such as laughter, excitement or fear. Other causes of cataplexy include Niemann-Pick type C Disease, Angelman Syndrome, Norrie Disease, Prader-Willi Syndrome. In addition, cataplexy can be a side effect of several drugs (eg, lamotrigine, clozapine, and gamma-hydroxybutyrate). Yet, the most prevalent causes of cataplexy without narcolepsy are rare genetic diseases; which explains why cataplexy is classically linked to narcolepsy. Therefore, it is essential disconnecting cataplexy from narcolepsy especially in pediatric population and after use of a few medications. In this review, we described few conditions of cataplexy not related to narcolepsy. We performed a review of literature (MEDLINE and EMBASE database), without limited date or publication restrictions.

Cognitive Improvements in Children with Prader-Willi Syndrome Following Pitolisant Treatment-Patient Reports

While children with Prader-Willi Syndrome (PWS), a rare genetic disease with an incidence of 1:15,000, typically present with hypotonia and hyperphagia, their lives are made more difficult by an ever-present sleepiness as well as multiple neuro-cognitive dysfunctions, including cognitive defects. We describe a case series of 3 children who were treated with the histamine 3 receptor inverse agonist pitolisant. While this first-in-class inverse agonist is approved for another orphan disease (i.e., narcolepsy with or without cataplexy), we have observed that pediatric patients with PWS prescribed pitolisant demonstrate decreased daytime sleepiness and improved cognition, as evidenced by increased processing speed and improved mental clarity. Pitolisant may represent a novel therapeutic option that might relieve substantial PWS disease burden, including cognitive disability, excessive daytime sleepiness, and poor-quality nighttime sleep.

Caregiver priorities for endpoints to evaluate treatments for Prader-Willi syndrome: a best-worst scaling

OBJECTIVES

Prader-Willi syndrome (PWS) is a rare genetic disorder associated with varying degrees of hyperphagia, obesity, intellectual disability, and anxiety across the affected individuals' lifetimes. This study quantified caregiver priorities for potential treatment endpoints to identify unmet needs in PWS.

METHODS

The authors partnered with the International Consortium to Advance Clinical Trials for PWS (PWS-CTC) and a diverse stakeholder advisory board to develop a best-worst scaling instrument. Seven relevant endpoints were assessed using a balanced incomplete block design. Caregivers were asked to determine the most and least important of a sub-set of four endpoints in each task. Caregivers were recruited nationally though patient registries, email lists, and social media. Best-worst score was calculated to determine caregiver priorities; ranging from 0 (least important) to 10 (most important). A novel kernel-smoothing approach was used to analyze caregiver endpoint priority variations with relation to age of the PWS individual.

RESULTS

In total, 457 caregivers participated in the study. Respondents were mostly parents (97%), females (83%), and Caucasian (87%) who cared for a PWS individual ranging from 4-54 years. Caregivers value treatments addressing hyperphagia (score = 7.08, SE = 0.17) and anxiety (score = 6.35, SE = 0.16) as most important. Key variations in priorities were observed across age, including treatments targeting anxiety, temper outbursts, and intellectual functions.

CONCLUSIONS

This study demonstrates that caregivers prioritize hyperphagia and, using a novel method, demonstrates that this is independent of the age of the person with PWS. This is even the case for parents of young children who have yet to experience hyperphagia, indicating that these results are not subject to a hypothetical bias.

Orthognathic Correction in Prader-Willi Syndrome: Occlusion and Sleep Restored

Children with Prader-Willi Syndrome (PWS) may present with a malocclusion and have a high propensity of developing obstructive sleep apnea (OSA). Obstructive sleep apnea is associated with short- and long-term adverse effects that negatively impact children with PWS. A case of a 15-year-old male with PWS, OSA, and a debilitating malocclusion is presented who underwent a combination of Le Fort 1 osteotomy, genioplasty, and tongue reduction to successfully treat his OSA and malocclusion. In select cases, orthognathic correction and other surgical therapies should be considered in patients with PWS.

Venovenous Extracorporeal Membrane Oxygenation in an Adult Patient With Prader-Willi Syndrome: A Nutrition Case Report

Prader-Willi Syndrome (PWS) is a genetic condition that results in a constellation of symptoms and typically results in hyperphagia and obesity in adulthood. Critically ill adults with PWS present a unique challenge to the nutrition professional, particularly when they require support modalities such as extracorporeal membrane oxygenation (ECMO). The purpose of this case study is to review the nutrition care of a critically ill adult patient with PWS who required venovenous ECMO. The patient was successfully managed with a hypocaloric, high-protein approach, which did not result in the diagnosis of malnutrition during his hospitalization. The patient was ultimately transitioned off extracorporeal life support and discharged to a rehabilitation facility.

Relative Contributions of Lean and Fat Mass to Bone Mineral Density: Insight From Prader-Willi Syndrome

Context: Low bone mineral density (BMD) is the most important risk factor for fragility fracture. Body weight is a simple screening predictor of difference in BMD between individuals. However, it is not clear which component of body weight, lean (LM), or fat mass (FM), is associated with BMD. People with the genetic disorder of Prader-Willi syndrome (PWS) uniquely have a reduced LM despite increased FM. Objective: We sought to define the individual impact of LM and FM on BMD by investigating subjects with and without PWS. Design, Setting and Participants: This cross-sectional study was conducted at the Clinical Research Facility of the Garvan Institute of Medical Research, with PWS and control participants recruited from a specialized PWS clinic and from the general public by advertisement, respectively. The study involved 11 adults with PWS, who were age- and sex-matched with 12 obese individuals (Obese group) and 10 lean individuals (Lean group). Main Outcome Measures: Whole body BMD was measured by dual-energy X-ray absorptiometry. Total body FM and LM were derived from the whole body scan. Differences in BMD between groups were assessed by the analysis of covariance model, taking into account the effects of LM and FM. Results: The PWS group had significantly shorter height than the lean and obese groups. As expected, there was no significant difference in FM between the Obese and PWS group, and no significant difference in LM between the Lean and PWS group. However, obese individuals had greater LM than lean individuals. BMD in lean individuals was significantly lower than in PWS individuals (1.13 g/cm² vs. 1.21 g/cm², p < 0.05) and obese individuals (1.13 g/cm² vs. 1.25 g/cm², p < 0.05). After adjusting for both LM and FM, there was no significant difference in BMD between groups, and the only significant predictor of BMD was LM. Conclusions: These data from the human genetic model Prader-Willi syndrome suggest that LM is a stronger determinant of BMD than fat mass.

Necdin shapes serotonergic development and SERT activity modulating breathing in a mouse model for Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder that presents with hypotonia and respiratory distress in neonates. The Necdin-deficient mouse is the only model that reproduces the respiratory phenotype of PWS (central apnea and blunted response to respiratory challenges). Here, we report that Necdin deletion disturbs the migration of serotonin (5-HT) neuronal precursors, leading to altered global serotonergic neuroarchitecture and increased spontaneous firing of 5-HT neurons. We show an increased expression and activity of 5-HT Transporter (SERT/Slc6a4) in 5-HT neurons leading to an increase of 5-HT uptake. In Necdin-KO pups, the genetic deletion of Slc6a4 or treatment with Fluoxetine, a 5-HT reuptake inhibitor, restored normal breathing. Unexpectedly, Fluoxetine administration was associated with respiratory side effects in wild-type animals. Overall, our results demonstrate that an increase of SERT activity is sufficient to cause the apneas in Necdin-KO pups, and that fluoxetine may offer therapeutic benefits to PWS patients with respiratory complications.

Prader-Willi syndrome results from the disruption of a cluster of neighboring genes, including one called Necdin. Symptoms begin in early infancy and worsen with age. Affected children tend to develop an insatiable appetite, which often leads to obesity. They also experience serious problems with their breathing. Chest infections, high altitude and intense physical activity can be dangerous for children with Prader-Willi syndrome. This is because a slight shortage of oxygen may trigger breathing difficulties that could prove fatal.

The brain cells that produce a chemical messenger called serotonin help to control breathing. Several lines of evidence suggest that loss of Necdin may trigger breathing difficulties in Prader-Willi syndrome via effects on the serotonin system. First, serotonin neurons produce the Necdin protein. Second, laboratory mice that lack the gene for Necdin have abnormally shaped serotonin neurons. Third, these mice show breathing difficulties like those of individuals with Prader-Willi syndrome. But while this implies a connection between serotonin, Necdin and breathing difficulties, it falls short of establishing a causal link.

Matarazzo et al. now reveal an increase in the quantity and activity of a protein called the serotonin transporter in mutant mice that lacked the gene for Necdin compared to normal mice. Serotonin transporter proteins mop up the serotonin that neurons release when they signal to one another. Neurons in the mutant mice take up more serotonin than their counterparts in normal mice; this means they have less serotonin available for signaling. This may make it harder for the mutant mice to regulate their breathing.

Drugs called selective serotonin-reuptake inhibitors (or SSRIs for short) can block the serotonin transporter. These drugs, which include Fluoxetine (also called Prozac), are antidepressants. Matarazzo et al. show that SSRIs temporarily restore normal breathing in young mice that lack the gene for Necdin. However, these drugs have harmful long-term effects on breathing in non-mutant mice. Further studies should test whether short-term use of SSRIs could offer immediate relief for breathing difficulties in infants and children with Prader-Willi syndrome.

Sleep-related breathing disorders in patients with Prader-Willi syndrome depending on the period of growth hormone treatment

INTRODUCTION

Sleep-related breathing disorders (SRBD) are commonly present in patients with Prader-Willi syndrome (PWS). Recombinant human growth hormone (rhGH) treatment is reported to improve breathing function in PWS, but the findings are not explicit.

MATERIAL AND METHODS

Screening polysomnography- polygraphy (PSG), assessing nasal respiratory flow, respiratory effort, and blood oxygen saturation, was used. Group 1 - before rhGH therapy (n = 11, mean age 3.0 years); PSG was repeated after the start of rhGH therapy in a mean time of 0.9 years in six patients (Group 1a). Group 2 - on rhGH treatment, for a mean time of four years (n = 17, mean age 8.8 years). Group 3 - without rhGH therapy due to severe obesity (n = 8, mean age 13.1 years).

RESULTS

Group 1 - mean apnoea-hypopnoea index (AHI) was 10.2, oxygen desaturation index (ODI)- 36.3, Group 1a- AHI 12.0, ODI 60.9, Group 2-AHI 9.0, ODI 25.1, Group 3- AHI 8.2, ODI 22.0. ODI was significantly higher in Group 1a than in the other groups (p < 0.005), but not strictly related to SRBD. The results in Group 2 did not differ significantly from those of Group 1.

CONCLUSIONS

Our study proves the high frequency of SRBD among PWS patients, with worsening of ODI after short-term rhGH therapy.

[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.

Two patients with chromosome 22q11.2 deletion presenting with childhood obesity and hyperphagia

Chromosome 22q11.2 deletion syndrome is a clinically heterogeneous condition of intellectual disability, parathyroid and thyroid hypoplasia, palatal abnormalities, cardiac malformations and psychiatric symptoms. Hyperphagia and childhood obesity is widely reported in Prader-Willi Syndrome (PWS) but there is only one previous report of this presentation in chromosome 22q11.2 deletion syndrome. We describe two further cases of chromosome 22q11.2 deletion syndrome in which hyperphagia and childhood obesity were the presenting features. This may be a manifestation of obsessive behaviour secondary to some of the psychiatric features commonly seen in chromosome 22q11.2 deletion syndrome. Serious complications may result from hyperphagia and childhood obesity therefore early recognition and intervention is crucial. Due to the similar clinical presentation of these two patients to patients with PWS, it is suggested that the hyperphagia seen here should be managed in a similar way to how it is managed in PWS.

Behavioral and emotional manifestations in a child with Prader-Willi syndrome

Prader-Willi syndrome is a neurodevelopmental disorder characterized by mental retardation and distinct physical, behavioral, and psychiatric features. Maladaptive behaviours, cognitive impairment, and impediments in speech and language seriously affect the early development and long-term functioning of individuals affected by the illness. We present a case of a 9-year-old child with Prader-Willi syndrome whose behavioural symptoms were treated with low-dose antipsychotic medications.

Growth hormone treatment of Prader-Willi syndrome has long-term, positive effects on body composition

AIM

Growth hormone (GH) treatment is a relatively new concept in adults, and the knowledge of its long-term effects is limited. We studied ten men with Prader-Willi Syndrome (PWS) after more than 5 years of GH treatment.

METHODS

Study participants underwent a detailed physical examination, including blood tests. Five had received GH as childhood and five had started GH as adults.

RESULTS

The total duration of GH treatment was 16 ± 4 years in the childhood PWS group and 15 ± 1 years in the adulthood PWS group. Their respective mean ages were 27 ± 4 years and 44 ± 4 years, mean heights were 178 ± 11 cm and 156 ± 5 cm, and mean body mass indexes were 32.4 ± 10.3 kg/m(2) and 28.9 ± 4.6 kg/m(2) . There were no differences in body composition between the groups and all lipids and insulin-like growth factor 1 were normal or close to normal. Four had well-controlled type 2 diabetes. The GH doses in the childhood and adulthood groups were 0.4 mg and 0.3 mg, respectively.

CONCLUSION

Men with PWS who received GH treatment displayed positive effects on body composition independent of when the GH treatment had started. Only patients who gained weight developed diabetes. The duration of GH treatment should balance the benefits and observed side effects.

A population-based profile of 160 Australians with Prader-Willi syndrome: trends in diagnosis, birth prevalence and birth characteristics

Perceived temporal trends in recognition and diagnosis of Prader-Willi syndrome served as the rationale for an updated epidemiological profile of individuals with this syndrome. Data from the Victorian Prader-Willi Syndrome Register were used to explore birth prevalence, birth characteristics, timing of diagnosis, and molecular mechanism, and to identify trends over time. Maternal age, birth gestation, small for gestational age, and sex were compared across molecular mechanisms. Between 1951 and 2012 there were 160 individuals with Prader-Willi syndrome, known to the Victorian Prader-Willi Syndrome Register, who were born in the Australian state of Victoria. The birth prevalence for individuals with a molecular diagnosis of Prader-Willi syndrome was estimated to be 1:15,830 for 2003-2012. Compared to 1973-1981, the decade 2003-2012 saw an increase in the rate of molecular diagnosis from 58% to 96%, more complete identification of the molecular mechanism (42% vs. 83%), earlier molecular diagnosis (1.3 years vs. 8.6 weeks), and a rise in the relative proportion of maternal uniparental disomy from 0% to 45%. One quarter of infants was born preterm and 53% were small for gestational age. This study confirms a temporal change in diagnostic patterns, suggests a greater relative contribution of maternal uniparental disomy as a molecular mechanism, provides a more robust estimate of birth prevalence and provides evidence of in utero growth restriction for this group. These findings have important clinical and health service delivery implications and pave the way for further research in Prader-Willi syndrome.

Patterns of habitual physical activity in youth with and without Prader-Willi Syndrome

Children classified as overweight or obese and those with disabilities are at a greater risk of not meeting the minimum recommendation of 60 min a day of moderate to vigorous physical activity (PA). Youth with Prader-Willi Syndrome (PWS) appear to participate in less PA compared to nonsyndromal children, likely due to syndrome-related factors. However, description of PA patterns in youth with PWS is lacking. The purpose of this study was to characterize PA in youth with PWS and to compare it to PA in children with nonsyndromal obesity. Twenty-four youth with PWS (ages 8-16 years) and 40 obese children without PWS (OB) (ages 8-11 years) wore accelerometers for eight consecutive days. Data were screened for compliance and classified into PA intensities: sedentary behavior (SED), light (LPA), moderate (MPA), vigorous (VPA) and moderate plus vigorous (MVPA). Youth with PWS spent 19.4% less time in weekly LPA (p=0.007) and 29.8% less time in weekly VPA compared to OB controls (p=0.036). All other intensities were similar between groups. In addition, PWS participated in less LPA and VPA during the weekends compared to OB, and less LPA on weekdays when compared to OB. There was also a trend towards PWS participating in less MVPA during the weekends and less VPA during the weekends than OB controls. There was a trend towards PWS participating in less VPA on weekends compared to weekdays, while OB participated similarly in VPA on weekdays and weekend days. On average, neither PWS nor OB children met minimum MVPA recommendations. The results suggest there is a need to design exercise programs for PWS youth that focus on integrating vigorous intensity activities, especially during the weekends when structured PA may not be available.

Velopharyngeal dysfunction in children with Prader-Willi syndrome after adenotonsillectomy

INTRODUCTION

Prader-Willi syndrome (PWS) is a rare genetic disorder with an incidence rate of 1 in 10,000-30,000. Patients with PWS typically have symptoms related to hypotonia, obesity, and hypothalamic dysfunction. A high rate of obstructive sleep apnea (OSA) is found among this population of patients. Adenotonsillectomy has been advocated as a first line approach for treatment of OSA in patients with PWS. Velopharyngeal dysfunction (VPD) is a known complication of adenotonsillectomy. VPD can also be present in patients with global hypotonia, such as those with PWS. The objective of this study is to review the occurrence of VPD in patients with PWS after adenotonsillectomy for OSA.

METHODS

A retrospective review was performed of all patients with PWS and OSA from a tertiary pediatric hospital between the years of 2002 and 2012. Pre- and post-operative sleep studies and sleep disordered breathing symptoms, post-operative VPD assessment by the speech-language pathologist (SLP), and VPD treatments were evaluated.

RESULTS

Eleven patients (five males and six females), fitting the inclusion criteria, were identified. The age of the patient at the initial otolaryngologic evaluation ranged from 2 to 9 years. All patients underwent adenotonsillectomy for sleep disordered breathing. Four patients were diagnosed with post-operative hypernasality after assessment by a speech-language pathologist. The hypernasality ranged from mild to moderately severe. Of the four patients with hypernasality, two were found to have structural issues requiring surgery (pharyngeal flap). Both of the surgical patients experienced significant improvement in their VPD after surgery. The remaining two patients were found to have articulation error patterns that were considered more developmental in nature and both responded to speech therapy. All patients, except one, had improvement in their polysomnogram or sleep symptoms after adenotonsillectomy. However, three patients continue to require continuous positive airway pressure at night.

CONCLUSION

Velopharyngeal dysfunction may occur after adenotonsillectomy in patients with Prader-Willi Syndrome. Families should be counseled of this risk and the potential need for operative intervention to correct it.

Leptin signaling defects in a mouse model of Prader-Willi syndrome: An orphan genetic obesity syndrome no more?

Prader-Willi syndrome (PWS) is a rare (~1 in 12,000) genetic disorder that involves at least six genes on chromosome 15q11–q13. Children with PWS not only rapidly gain weight and become severely obese because of reduced voluntary activity and increased food intake, but also exhibit growth hormone deficiency, excessive daytime sleepiness, endocrine dysregulation and infertility. These phenotypes suggest dysfunction of the hypothalamus, the brain region that regulates short- and long-term energy balance and other body functions. The physiological basis for obesity in children with PWS has eluded researchers for decades. Mercer et al. now demonstrate that Magel2, the murine ortholog of one of the PWS genes, is a component of the hypothalamic leptin-melanocortin pathway that is critical for energy balance. Most interestingly, disruptions of other components of this pathway cause obesity in both mice and humans, suggesting a mechanistic link between PWS and other rare genetic forms of severe childhood-onset obesity.

Mental health problems in children with prader-willi syndrome

BACKGROUND

Prader-Willi Syndrome (PWS) is a genetically determined neurodevelopmental disorder, which occurs in approximately one in 22000 births.

AIMS

This study aimed to investigate psychiatric characteristics of children diagnosed with PWS compared with an age-, gender- and IQ-matched control group. The parents of children with PWS were assessed for psychological distress in comparison to the parents of the control group. Methodological limitations identified in previous studies were addressed in the present study.

METHODS

Psychiatric problems were evaluated in a sample of children with genetically confirmed PWS and an age- and IQ-matched control group using the Child Behaviour Checklist 6-18. Parental psychological distress for both groups was evaluated with the Brief Symptom Inventory.

RESULTS

Children with PWS had more severe somatic, social, and thought problems, and were more withdrawn-depressed in comparison to controls. Borderline difficulties were detected for the affective, somatic, and attention deficit-hyperactivity CBCL DSM-orientated subscales in the PWS group. Parents of PWS children, in comparison to controls, had more somatization, phobic anxiety, obsessive-compulsive, and anxiety problems.

CONCLUSIONS

PWS represents a complex psychological disorder with multiple areas of disturbances.