Cognitive and behavioural aspects of Prader-Willi syndrome

Role of projective psychological tests in patients with Prader-Willi syndrome

INTRODUCTION

The purpose of this study was to evaluate the usefulness and relevance of projective techniques such as house-tree-person (HTP) and family in individuals with Prader-Willi syndrome (PWS), who have a limited ability to identify and verbalize emotions and express them often using behaviors.

METHODS

We included individuals with genetic confirmation of PWS immersed in a regular transdisciplinary treatment in an institution dedicated to rare diseases. All individuals were evaluated using the HTP and family projective techniques. These instruments are commonly administered to the general population and, in this case, to people with mild to moderate intellectual disabilities, including difficulties in their communication abilities.

RESULTS

A total of 25 individuals with PWS between 10 and 41 years old (15 men and 10 women) were included. We identified the presence of graphic indicators corresponding to the behavioral phenotype of individuals with PWS, such as anxiety, stubbornness, emotional lability, difficulty in achieving adequate externalization and identification of emotions, impulsivity, aggressive traits, poor social skills, need for support and interaction, low self-concept, and compulsive behaviors.

CONCLUSIONS

In the present study, we demonstrated the usefulness of graphic techniques to elucidate aspects of behavior, emotions, and thoughts that individuals with PWS cannot formulate due to expression and communication difficulties.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication

BACKGROUND

Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication.

METHODS

Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication.

RESULTS

The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis.

CONCLUSIONS

Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

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.

Effectiveness of the Kaufman Brief Intelligence Test in people with Prader-Willi syndrome

BACKGROUND

Evaluating intelligence using conventional tools is very complex in patients with Prader-Willi Syndrome (PWS), as it is time consuming and requires levels of care that are difficult to sustain for this population. Therefore, we explore the ability of a brief test to assess intelligence in these patients.

METHODS

This study included individuals with a genetically confirmed diagnosis of PWS, with regular attendance at transdisciplinary treatment in an institution dedicated to the care of rare diseases in Argentina. The Wechsler Intelligence Scale for Children (WISC-IV), the Wechsler Adult Intelligence Scale (WAIS-III) and the Kaufman Brief Intelligence Test (K-BIT) were used.

RESULTS

Correlation was obtained between the scales in paediatric and adult populations. Within the paediatric population, no significant differences were identified between the WISC-IV scale (Wechsler for paediatrics) and the K-BIT (56.4 ± 8.6, vs. 53.4 ± 10.1, P = 0.28), with a good agreement between the methods {intraclass correlation 0.79 [95% confidence interval (CI) 0.15-0.95]}. Regarding the adult population, the discrimination of the WAIS-III scale (Wechsler for adults) and the K-BIT of adults (16 years and over) presented an acceptable concordance [0.77 (95% CI -0.09; 0.93)], although also underestimating the results (58.3 ± 7.2 vs. 51.1 ± 11.2, P < 0.0001).

CONCLUSIONS

We observed the feasibility and potential usefulness of a brief intelligence test (K-BIT) in patients with PWS with an acceptable agreement with conventional tools.

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.

Cognitive and Adaptive Effects of Early Growth Hormone Treatment in Prader-Willi Syndrome Patients: A Cohort Study

Background: Prader–Willi Syndrome (PWS) is a genetically based neurodevelopmental disease characterized by obesity, hyperphagia, and mild to moderate intellectual disability. Treatment with growth hormone (GH) could provide cognitive benefits. The objective of the present study was to compare the cognitive and adaptive performance of 31 patients with genetically confirmed PWS grouped in two cohorts, one treated with GH before 2 years old (Group 1) and the other receiving the treatment later (Group 2). Method: We compared two variables necessary to diagnose intellectual disability: intellectual performance, using the Weschler scales, and adaptive behavior, using the DABS scale. The scores were analyzed by means of non-parametric statistical tests. Results: Group 1 (n = 10) obtained higher and statistically significant scores in Total Intelligence Quotient (TIQ), General Ability Index (GAI), and General Adaptive Behavior (GAB), implying better cognitive and adaptive performance compared to Group 2. Conclusions: Treatment with GH should be administered in the early stage of development (before 2 years old) to obtain greater benefits at the cognitive and adaptive levels.

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

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

The influence of emotional contexts on mental flexibility in Prader-Willi syndrome

BACKGROUND

The present study investigated the influence of emotional contexts on mental flexibility in adults with Prader-Willi syndrome (PWS) using a voluntary task-switching paradigm that was implemented with emotionally valenced pictures. The study aims were to assess whether adults with PWS have impaired switching abilities, whether the deficit is specific to PWS or linked to intellectual disabilities, and the influence of emotional contexts on performance.

METHOD

The task-switching performance of 30 adults with PWS was compared with that of 30 healthy adults matched on chronological age, and to that of 30 adults with intellectual disabilities but without PWS, matched on intellectual quotient level and chronological age. Indicators of switching performance were switching cost and repetition bias. Emotional contexts were operationalised with positive, neutral and negative task-irrelevant pictures.

RESULTS

Adults with PWS showed a large increase in switching costs compared with the two control groups, and this effect did not vary across emotional contexts. More fine-tuned examination revealed subtle performance modulations: negative contexts tended to increase the repetition bias in all three groups while positive contexts slowed down global performance in PWS.

CONCLUSIONS

The results confirmed previous studies, showing impaired switching abilities in PWS over and beyond the influence of intellectual level, but revealed no robust variations in switching deficits across emotional contexts.

Hypogonadism in Women with Prader-Willi Syndrome-Clinical Recommendations Based on a Dutch Cohort Study, Review of the Literature and an International Expert Panel Discussion

Prader-Willi syndrome (PWS) is a rare neuroendocrine genetic syndrome. Characteristics of PWS include hyperphagia, hypotonia, and intellectual disability. Pituitary hormone deficiencies, caused by hypothalamic dysfunction, are common and hypogonadism is the most prevalent. Untreated hypogonadism can cause osteoporosis, which is already an important issue in PWS. Therefore, timely detection and treatment of hypogonadism is crucial. To increase understanding and prevent undertreatment, we (1) performed a cohort study in the Dutch PWS population, (2) thoroughly reviewed the literature on female hypogonadism in PWS and (3) provide clinical recommendations on behalf of an international expert panel. For the cohort study, we retrospectively collected results of a systematic health screening in 64 female adults with PWS, which included a medical questionnaire, medical file search, medical interview, physical examination and biochemical measurements. Our data show that hypogonadism is frequent in females with PWS (94%), but is often undiagnosed and untreated. This could be related to unfamiliarity with the syndrome, fear of behavioral changes, hygienic concerns, or drug interactions. To prevent underdiagnosis and undertreatment, we provide practical recommendations for the screening and treatment of hypogonadism in females with PWS.

Suicidality and Self-Harming Behaviors in Patients with Prader-Willi Syndrome (PWS): Case Report and Literature Review

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder which is often associated with significant behavioral challenges and poor intellectual functioning. Research has shown that individuals with PWS are more likely to experience mental health problems, have higher relapse rates, and are at risk of self-harming behavior. Although PWS is associated with mild intellectual disability, which in itself confers a higher mortality rate, suicidality in this population is so far unreported in the literature. We present the case of an 18-year-old male patient who was admitted to our facility following exogenous insulin administration with suicidal intent. The main clinical characteristics, self-harming behaviors, and suicide risk factors of patients with PWS are discussed in this report. The article's objective is to redirect clinicians' attention to carefully screen and treat the underlying behavioral problems in PWS patients.

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

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

Bridging Oral and Systemic Health in Children with Prader-Willi Syndrome: Case Reports and Dental Treatment Recommendations

BACKGROUND

Prader-Willi Syndrome (PWS) is a complex neurodevelopmental disorder caused by gene alterations on chromosome 15q11-q13, resulting in hyperphagia and neuroendocrine deficits. A comprehensive guide for dental treatment for PWS is lacking despite numerous case reports. The objective of this report was to develop a problem-focused list of the interrelationship between oral and systemic parameters of PWS and enable dentists in anticipating the unique treatment needs of children and individuals with PWS.

METHODS

Four pediatric patients with PWS presenting to an academic dental clinic were evaluated. A literature review spanning the last twenty years was performed to identify the pathophysiological impact of systemic problems on dental health and treatment.

RESULTS

The four cases along with cases from the literature were used to enumerate salient oro-dental and systemic features influencing treatment decisions in dentistry. They formed the basis for collective recommendations and precautions for rendering dental treatment in patients with PWS.

CONCLUSION

Sedation for dental treatment is contraindicated due to obesity (BMI over 95th percentile), hypotonia, obstructive sleep apnea (OSA), and respiratory limitations (restricted ventilation due to weight on thoracic cage). Prolonged recovery from general anesthesia, OSA, and temperature dysregulation necessitate extended monitoring after dental rehabilitation under general anesthesia. Orthopedic problems and respiratory limitations exclude protective stabilization. Xerostomia and acidic saliva necessitate recommendations for oral rehydrating products. Periodontal assessment is necessary due to poor oral hygiene and diabetes mellitus. Early establishment of a dental home and risk-based frequency of dental care should address caries prevention and restorative needs.

Neurocognitive and Neurobehavioral Phenotype of Youth with Schaaf-Yang Syndrome

Truncating variants of the MAGEL2 gene, one of the protein-coding genes within the Prader-Willi syndrome (PWS) critical region on chromosome 15q11, cause Schaaf-Yang syndrome (SYS)-a neurodevelopmental disorder that shares several clinical features with PWS. The current study sought to characterize the neurobehavioral phenotype of SYS in a sample of 9 patients with molecularly-confirmed SYS. Participants received an assessment of developmental/intellectual functioning, adaptive functioning, autism symptomatology, and behavioral/emotional functioning. Compared to individuals with PWS, patients with SYS manifested more severe cognitive deficits, no obsessions or compulsions, and increased rates of autism spectrum disorder.

Face processing and exploration of social signals in Prader-Willi syndrome: a genetic signature

BACKGROUND

Faces are critical social cues that must be perfectly processed in order to engage appropriately in everyday social interactions. In Prader-Willi Syndrome (PWS), a rare genetic disorder characterized by cognitive and behavioural difficulties including autism spectrum disorder, the literature referring to face processing is sparse. Given reports of poor social interactions in individuals with PWS, we sought to assess their face and emotion recognition skills during eyetracking recordings.

RESULTS

Compared with controls, patients with PWS performed more poorly on face/emotion recognition. We observed atypical facial exploration by patients with maternal disomy. These patients looked preferentially at the mouth region, whereas patients with a deletion and controls were more attracted to the eye region. During social scenes, the exploration became more atypical as the social content increased.

CONCLUSIONS

Our comprehensive study brings new insights into the face processing of patients with PWS. Atypical facial exploration was only displayed by patients with the maternal disomy subtype, corresponding to their higher rate of autism spectrum disorder. This finding strongly argues in favor of early identification of this genetic subgroup in order to optimize care by implementing tailored interventions for each patient as soon as possible.

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

OBJECTIVE

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

DATA SOURCES

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update

BACKGROUND

Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder with lack of expression of genes inherited from the paternal chromosome 15q11-q13 region usually from paternal 15q11-q13 deletions (about 60%) or maternal uniparental disomy 15 or both 15s from the mother (about 35%). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. Key findings include infantile hypotonia, a poor suck, failure to thrive and hypogonadism/hypogenitalism. Short stature and small hands/feet due to growth and other hormone deficiencies, hyperphagia and marked obesity occur in early childhood, if uncontrolled. Cognitive and behavioral problems (tantrums, compulsions, compulsive skin picking) are common.

OBJECTIVE

Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS. This report will describe an accurate diagnosis with determination of specific genetic subtypes, appropriate medical management and best practice treatment approaches.

METHODS AND RESULTS

An extensive literature review was undertaken related to genetics, clinical findings and laboratory testing, clinical and behavioral assessments and summary of updated health-related information addressing the importance of early PWS diagnosis and treatment. A searchable, bulleted and formatted list of topics is provided utilizing a Table of Contents approach for the clinical practitioner.

CONCLUSION

Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections pertinent in the context of clinical practice. Frequently asked questions by clinicians, families and other interested participants or providers will be addressed.

Oxytocin and Prader-Willi Syndrome

In the chapter, we explore the relationship between the peptide hormone, oxytocin (OT), and behavioral and metabolic disturbances observed in the genetic disorder Prader-Willi Syndrome (PWS). Phenotypic and genotypic characteristics of PWS are described, as are the potential implications of an abnormal OT system with respect to neural development including the possible effects of OT dysfunction on interactions with other regulatory mediators, including neurotransmitters, neuromodulators, and hormones. The major behavioral characteristics are explored in the context of OT dysfunction, including hyperphagia, impulsivity, anxiety and emotion dysregulation, sensory processing and interoception, repetitive and restrictive behaviors, and dysfunctional social cognition. Behavioral overlaps with autistic spectrum disorders are discussed. The implications of OT dysfunction on the mechanisms of reward and satiety and their possible role in informing behavioral characteristics are also discussed. Treatment implications and future directions for investigation are considered.

Incidental memory for faces in children with different genetic subtypes of Prader-Willi syndrome

The present study examined the effects of genetic subtype on social memory in children (7–16 years) with Prader–Willi syndrome (PWS). Visual event-related potentials (ERPs) during a passive viewing task were used to compare incidental memory traces for repeated vs single presentations of previously unfamiliar social (faces) and nonsocial (houses) images in 15 children with the deletion subtype and 13 children with maternal uniparental disomy (mUPD). While all participants perceived faces as different from houses (N170 responses), repeated faces elicited more positive ERP amplitudes (‘old/new’ effect, 250–500ms) only in children with the deletion subtype. Conversely, the mUPD group demonstrated reduced amplitudes suggestive of habituation to the repeated faces. ERP responses to repeated vs single house images did not differ in either group. The results suggest that faces hold different motivational value for individuals with the deletion vs mUPD subtype of PWS and could contribute to the explanation of subtype differences in the psychiatric symptoms, including autism symptomatology.

Neuroanatomical and molecular correlates of cognitive and behavioural outcomes in hypogonadal males

Robust epidemiological, clinical and laboratory evidence supports emerging roles for the sex steroids in such domains as neurodevelopment, behaviour, learning and cognition. Regions of the mammalian brain that are involved in cognitive development and memory do not only express the classical nuclear androgen receptor, but also the non-genomic membrane receptor, which is a G protein-coupled receptor that mediates some rapid effects of the androgens on neurogenesis and synaptic plasticity. Under physiological conditions, hippocampal neurons do express the enzyme aromatase, and therefore actively aromatize testosterone to oestradiol. Although glial expression of the aromatase enzyme is minimal, increased expression following injury suggests a role for sex steroids in neuroprotection. It is therefore plausible to deduce that low levels of circulating androgens in males would perturb neuronal functions in relation to cognition and memory, as well as neural repair following injury. The present review is an overview of some roles of the sex steroids on cognitive function in males, and the neuroanatomical and molecular underpinnings of some behavioural and cognitive deficits characteristic of such genetic disorders noted for low androgen levels, including Klinefelter syndrome, Bardet-Biedl syndrome, Kallman syndrome and Prader-Willi syndrome. Recent literature in relation to some behavioural and cognitive changes secondary to surgical and pharmacological castration are also appraised.

Overview of Social Cognitive Dysfunctions in Rare Developmental Syndromes With Psychiatric Phenotype

Rare neurodevelopmental syndromes often present social cognitive deficits that may underlie difficulties in social interactions and increase the risk of psychosis or autism spectrum disorders. However, little is known regarding the specificities of social cognitive impairment across syndromes while it remains a major challenge for the care. Our review provides an overview of social cognitive dysfunctions in rare diseases associated with psychiatric symptoms (with a prevalence estimated between 1 in 1,200 and 1 in 25,000 live births: 22q11.2 deletion syndrome, Angelman syndrome, Fragile X syndrome, Klinefelter syndrome, Prader-Willi syndrome, Rett syndrome, Smith-Magenis syndrome, Turner syndrome, and Williams syndrome) and shed some light on the specific mechanisms that may underlie these skills in each clinical presentation. We first detail the different processes included in the generic expression "social cognition" before summarizing the genotype, psychiatric phenotype, and non-social cognitive profile in each syndrome. Then, we offer a systematic review of the social cognitive abilities and the disturbed mechanisms they are likely associated with. We followed the PRISMA process, including the definition of the relevant search terms, the selection of studies based on clear inclusion, and exclusion criteria and the quality appraisal of papers. We finally provide insights that may have considerable influence on the development of adapted therapeutic interventions such as social cognitive training (SCT) therapies specifically designed to target the psychiatric phenotype. The results of this review suggest that social cognition impairments share some similarities across syndromes. We propose that social cognitive impairments are strongly involved in behavioral symptoms regardless of the overall cognitive level measured by intelligence quotient. Better understanding the mechanisms underlying impaired social cognition may lead to adapt therapeutic interventions. The studies targeting social cognition processes offer new thoughts about the development of specific cognitive training programs, as they highlight the importance of connecting neurocognitive and SCT techniques.

Behavioral Phenotyping Assays for Genetic Mouse Models of Neurodevelopmental, Neurodegenerative, and Psychiatric Disorders

Animal models offer heuristic research tools to understand the causes of human diseases and to identify potential treatments. With rapidly evolving genetic engineering technologies, mutations identified in a human disorder can be generated in the mouse genome. Phenotypic outcomes of the mutation are then explicated to confirm hypotheses about causes and to discover effective therapeutics. Most neurodevelopmental, neurodegenerative, and psychiatric disorders are diagnosed primarily by their prominent behavioral symptoms. Mouse behavioral assays analogous to the human symptoms have been developed to analyze the consequences of mutations and to evaluate proposed therapeutics preclinically. Here we describe the range of mouse behavioral tests available in the established behavioral neuroscience literature, along with examples of their translational applications. Concepts presented have been successfully used in other species, including flies, worms, fish, rats, pigs, and nonhuman primates. Identical strategies can be employed to test hypotheses about environmental causes and gene × environment interactions.

Oxytocin treatment in children with Prader-Willi syndrome: A double-blind, placebo-controlled, crossover study

Prader-Willi syndrome (PWS) is a rare, complex multisystem genetic disorder which includes hypothalamic dysfunction, hyperphagia, cognitive and behavioral problems, increased anxiety, and compulsive behaviors. Individuals with PWS have a deficit of oxytocin producing neurons in the paraventricular nucleus of the hypothalamus. Oxytocin plays a role in regulation of feeding behaviors, social interactions, and emotional reactivity, which are all issues that significantly affect the quality of life for individuals with this syndrome. We performed a double-blind, placebo-controlled, crossover study in 24 children with PWS at three academic institutions using 5 days of intranasal oxytocin (IN-OT) or 5 days of intranasal placebo spray, followed by a 4 week washout period, and then patients returned for 5 days of treatment with the alternate source. Questionnaires, including the Aberrant Behavior Checklist, Social Responsiveness Scale, Repetitive Behavior Scale - Revised, and the Hyperphagia Questionnaire, as well as Clinical Global Impression scales were administered. Blood testing for sodium, potassium, and glucose levels on days 2, 4, and 6, and a 24 hr diet recall. All scales factor improvement from Day 3 to Day 6 favored oxytocin over placebo. No single factor showed a statistically significant difference (P < 0.05) between groups at Day 6. The drug effect appeared to be diminished at Day 14. There was no evidence of a difference between oxytocin and placebo in safety lab parameters, 60 min post dose vital signs, weight, or diet parameters. The results from this study suggest that low dose intranasal oxytocin is safe for individuals with PWS and may result in reduction in appetite drive, and improvements in socialization, anxiety, and repetitive behaviors. Further, long-term studies with a larger population of participants are necessary to confirm these findings. The results of this study are encouraging that oxytocin may be a safe and effective treatment for many of the issues that negatively impact individuals with PWS.

Weight control and behavior rehabilitation in a patient suffering from Prader Willi syndrome

BACKGROUND

This study reports a case of Prader Willi syndrome (PWS), a genomic imprinting disease related to chromosome regions 15q11.2-q13 15, which includes hypothalamic dysfunction leading to hyperphagia, obesity, shortness, sleep abnormalities. Our case is extremely severe, in comparison to other PWS cases described in literature, due to the association with severe emotional and psychiatric symptoms: oppositional behaviour, rigidity of thought, skin picking and pathological hoarding.

CASE PRESENTATION

We described the case of a Caucasian male patient suffering from PWS, treated in outpatient care by local Mental Health Centre and supported by Social Service, who was admitted to a residential rehabilitative facility. After a 2-year follow-up, the patient showed a global improvement in symptoms and functioning, as registered by the rating scales administered. At the end of observation period, we also reported an important improvement in weight control, reducing the risk of obesity and related diseases, therefore improving the prognosis of life.

CONCLUSION

This case highlights the need for long-term, individualized and multi-professional treatment in patients suffering from a complex genetic syndrome with both organic and psychological alterations, for which medical care setting and pharmacological treatments are not sufficient. Clinical observation of this case leads us to compare PWS to drug addiction and indirectly endorse the neurophysiological hypothesis that food and drugs stimulate the same brain circuits in the limbic system.

Overview: referrals for genetic evaluation from child psychiatrists

A growing multitude of known genetic diagnoses can result in presentation to child psychiatry. For numerous reasons, it is important to identify a genetic etiology in child psychiatry patients when it is present. Genetic diagnoses can guide treatment and enable access to specialized clinics and appropriate screening measures. They can also allow for genetic counseling for the patient and family. A better understanding of etiology with a named diagnosis can itself be of great value to many patients and families; prognostic information can be empowering. Since patients with genetic conditions may present to psychiatric care in diverse ways, child psychiatrists must decide who to refer for genetic evaluation. Here we create a table to provide a framework of concerning/notable history and exam features that a practicing child psychiatrist may encounter that should prompt one to consider whether a larger, unifying genetic diagnosis is at hand. We hope this framework will facilitate referral of child psychiatry patients to genetics so that more patients can benefit from an appropriate diagnosis.

Clinical Application of an Innovative Multiplex-Fluorescent-Labeled STRs Assay for Prader-Willi Syndrome and Angelman Syndrome

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are two clinically distinct neurodevelopmental disorders caused by absence of paternally or maternally expressed imprinted genes on chr15q11.2-q13.3. Three mechanisms are known to be involved in the pathogenesis: microdeletions, uniparental disomy (UPD) and imprinting defects. Both disorders are difficult to be definitely diagnosed at early age if no available molecular cytogenetic tests. In this study, we identified 5 AS patients with the maternal deletion and 26 PWS patients with paternal deletion on chr15q11-q13 by using an innovative multiplex-fluorescent-labeled short tandem repeats (STRs) assay based on linkage analysis, and validated by the methylation-specific PCR and array comparative genomic hybridization techniques. More interesting, one of these PWS patients was confirmed as maternal uniparental isodisomy by the STR linkage analysis. The phenotypic and genotypic characteristics of these individuals were also presented. Our results indicate that the new linkage analysis is much faster and easier for large-scale screening deletion and uniparental disomy, thus providing a valuable method for early diagnosis of PWS/AS patients, which is critical for genetic diagnosis, management and improvement of prognosis.

Prader-Willi Syndrome and Schaaf-Yang Syndrome: Neurodevelopmental Diseases Intersecting at the MAGEL2 Gene

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by neonatal hypotonia, developmental delay/intellectual disability, and characteristic feeding behaviors with failure to thrive during infancy; followed by hyperphagia and excessive weight gain later in childhood. Individuals with PWS also manifest complex behavioral phenotypes. Approximately 25% meet criteria for autism spectrum disorder (ASD). PWS is caused by the absence of paternally expressed, maternally silenced genes at chromosome 15q11-q13. MAGEL2 is one of five protein-coding genes in the PWS-critical domain. Truncating point mutations of the paternal allele of MAGEL2 cause Schaaf-Yang syndrome, which has significant phenotypic overlap with PWS, but is also clinically distinct; based on the presence of joint contractures, and a particularly high prevalence of autism spectrum disorder (up to 75% of affected individuals). The clinical and molecular overlap between PWS and Schaaf-Yang syndrome, but also their distinguishing features provide insight into the pathogenetic mechanisms underlying both disorders.

A review of chemosensory perceptions, food preferences and food-related behaviours in subjects with Prader-Willi Syndrome

Hyperphagia and obsessive preoccupation with food are hallmark characteristics of Prader-Willi Syndrome (PWS). Although hyperphagia in PWS is linked to hypothalamic dysfunction, the underlying mechanisms behind this problem are poorly understood. Moreover, our understanding of how chemosensory perceptions and food choice/preferences relate to hyperphagia in individuals with PWS is very limited. This narrative review synthesizes studies that assessed chemosensory perceptions, food choices and food-related behaviours in PWS individuals and highlights knowledge gaps in research for further exploration. Twenty seven publications from relevant databases met inclusion criteria and were organized thematically by study technique in the review. Results suggested that PWS individuals have consistent preferences for sweet tastes and in most studies have exhibited a preference for calorie-dense foods over lower calorie foods. No firm conclusions were drawn concerning the chemosensory perceptions of PWS individuals and their influence on food preferences or choices; chemosensation among PWS individuals is an understudied topic. Current evidence suggests that eating behaviour in PWS is a complex phenomenon that involves a dysfunctional satiation and not excessive hunger. Food preferences, choices, and related behaviours and the impact of these on obesity management in those with PWS remain poorly understood and require further study using validated tools and methodologies.

The developmental trajectory of disruptive behavior in Down syndrome, fragile X syndrome, Prader-Willi syndrome and Williams syndrome

The aim of this study was to investigate the developmental trajectories of verbal aggression, physical aggression, and temper tantrums in four genetic syndrome groups. Participants were part of the Australian Child to Adult Development Study (ACAD), which collected information from a cohort of individuals with an intellectual disability at five time points over 18 years. Data were examined from a total of 248 people with one of the four following syndromes: Down syndrome, Fragile X syndrome, Prader-Willi syndrome, or Williams syndrome. Changes in behaviors were measured using validated items from the Developmental Behavior Checklist (DBC). The results indicate that, while verbal aggression shows no evidence of diminishing with age, physical aggression, and temper tantrums decline with age before 19 years for people with Down syndrome, Fragile X syndrome, and William syndrome; and after 19 years for people with Prader-Willi syndrome. These findings offer a somewhat more optimistic outlook for people with an intellectual disability than has previously been suggested. Research is needed to investigate the mechanisms predisposing people with PWS to persistence of temper tantrums and physical aggression into adulthood.