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

Psychotic illness in people with Prader-Willi syndrome: a systematic review of clinical presentation, course and phenomenology

BACKGROUND

Prader-Willi syndrome (PWS) is a rare and complex neurodevelopmental disorder resulting from absent paternal expression of maternally imprinted genes at chromosomal locus 15q11-13. This absence of expression occurs as a consequence of a deletion on the chromosome 15 of paternal origin (ca. 70%), a chromosome 15 maternal uniparental disomy (mUPD; ca. 25%), or an imprinting centre defect (IC; ca. 1-3%). At birth, individuals with PWS are severely hypotonic and fail to thrive. Hyperphagia and characteristic physical and neuropsychiatric phenotypes become apparent during childhood. The risk for the development of a co-morbid psychotic illness increases during the teenage years, specifically in those with PWS due to the presence of an mUPD. The primary aim of this literature review is to inform clinical practice. To achieve this, we have undertaken a systematic analysis of the clinical research literature on prevalence, presentation, course, characteristics, diagnosis and treatment of psychotic illness in people with PWS. The secondary aim is to identify clinical aspects of psychotic illness in PWS in need of further investigation.

METHODS AND FINDINGS

A systematic literature review on psychosis in PWS was conducted on the databases Web of Knowledge, PubMed and Scopus, using the terms "((Prader-Willi syndrome) OR (Prader Willi Syndrome)) AND ((psychosis) OR (psychotic illness))". All articles written in English and reporting original human research were reviewed. In all but three of the 16 cohort studies in which the genetic types were known, the authors reported higher rates of psychosis in people with PWS resulting from an mUPD, compared to those with the deletion subtype of PWS. When psychosis was present the presentation was psychosis similar regardless of genetic type and was usually characterised by an acute onset of hallucinations and delusions accompanied by confusion, anxiety and motor symptoms.

CONCLUSIONS

The onset of confusion, an affective cyclical pattern with the presence of abnormal mental beliefs and experiences, usually of rapid onset is suggestive of the development of psychotic illness. Phenomenologically, this psychosis in people with PWS is atypical in comparison to schizophrenia and bipolar disorder in the general population. The relationship to psychosis in the general population and the optimum treatments remain uncertain.

Orthopedic manifestations in children with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disease often associated with bone problems, mainly scoliosis and hip dysplasia (HD). This study aimed to analyze the clinical characteristics of orthopedic deformities in patients with PWS.

METHODS

A retrospective study was conducted on 175 patients up to March 2023. The Cobb angle(CA) of the spine, the alpha angle of the hip joint, and the acetabular index (AI) were measured. This study aimed to evaluate the relationship between demographic parameters and bone deformities.

RESULTS

Scoliosis was found in 66 patients (43.7%), including 52 (78.8%) with mild scoliosis, 10 (15.2%) with moderate scoliosis, and 4 (6.1%) with severe scoliosis. Only seven patients received orthopedic treatment (10.6%). The median age of scoliosis was 4.5 years old, and the prevalence of scoliosis increased rapidly at the age of 5 years and adolescence. The mean CA in this study increased gradually with age. HD was found in 47 patients (38.2%), and 6 patients received orthopedic treatment (12.7%). The median age at HD was 1.8 years old. The mean AI of the study population decreased with age. The prevalence of HD treated with recombinant human growth hormone (rhGH) was low. No significant differences were observed in sex, genotype, body mass index (BMI), obesity rate, or onset of scoliosis and HD.

CONCLUSION

The prevalence of scoliosis and HD was higher in patients with PWS. The onset age and developmental trends of the different skeletal malformations were different. Early diagnosis and treatment are important for the prognosis and treatment of orthopedic diseases in patients with PWS.

Early life stress and altered social behaviors: A perspective across species

Childhood and adolescent affiliations guide how individuals engage in social relationships throughout their lifetime and adverse experiences can promote biological alterations that facilitate behavioral maladaptation. Indeed, childhood victims of abuse are more likely to be diagnosed with conduct or mood disorders which are both characterized by altered social engagement. A key domain particularly deserving of attention is aggressive behavior, a hallmark of many disorders characterized by deficits in reward processing. Animal models have been integral in identifying both the short- and long-term consequences of stress exposure and suggest that whether it is disruption to parental care or social isolation, chronic exposure to early life stress increases corticosterone, changes the expression of neurotransmitters and neuromodulators, and facilitates structural alterations to the hypothalamus, hippocampus, and amygdala, influencing how these brain regions communicate with other reward-related substrates. Herein, we describe how adverse early life experiences influence social behavioral outcomes across a wide range of species and highlight the long-term biological mechanisms that are most relevant to maladaptive aggressive behavior.

Hormonal Imbalances in Prader-Willi and Schaaf-Yang Syndromes Imply the Evolution of Specific Regulation of Hypothalamic Neuroendocrine Function in Mammals

The hypothalamus regulates fundamental aspects of physiological homeostasis and behavior, including stress response, reproduction, growth, sleep, and feeding, several of which are affected in patients with Prader-Willi (PWS) and Schaaf-Yang syndrome (SYS). PWS is caused by paternal deletion, maternal uniparental disomy, or imprinting defects that lead to loss of expression of a maternally imprinted region of chromosome 15 encompassing non-coding RNAs and five protein-coding genes; SYS patients have a mutation in one of them, MAGEL2. Throughout life, PWS and SYS patients suffer from musculoskeletal deficiencies, intellectual disabilities, and hormonal abnormalities, which lead to compulsive behaviors like hyperphagia and temper outbursts. Management of PWS and SYS is mostly symptomatic and cures for these debilitating disorders do not exist, highlighting a clear, unmet medical need. Research over several decades into the molecular and cellular roles of PWS genes has uncovered that several impinge on the neuroendocrine system. In this review, we will discuss the expression and molecular functions of PWS genes, connecting them with hormonal imbalances in patients and animal models. Besides the observed hormonal imbalances, we will describe the recent findings about how the loss of individual genes, particularly MAGEL2, affects the molecular mechanisms of hormone secretion. These results suggest that MAGEL2 evolved as a mammalian-specific regulator of hypothalamic neuroendocrine function.

Psychosis Caused by a Somatic Condition: How to Make the Diagnosis? A Systematic Literature Review

BACKGROUND

First episode of psychosis (FEP) is a clinical condition that usually occurs during adolescence or early adulthood and is often a sign of a future psychiatric disease. However, these symptoms are not specific, and psychosis can be caused by a physical disease in at least 5% of cases. Timely detection of these diseases, the first signs of which may appear in childhood, is of particular importance, as a curable treatment exists in most cases. However, there is no consensus in academic societies to offer recommendations for a comprehensive medical assessment to eliminate somatic causes.

METHODS

We conducted a systematic literature search using a two-fold research strategy to: (1) identify physical diseases that can be differentially diagnosed for psychosis; and (2) determine the paraclinical exams allowing us to exclude these pathologies.

RESULTS

We identified 85 articles describing the autoimmune, metabolic, neurologic, infectious, and genetic differential diagnoses of psychosis. Clinical presentations are described, and a complete list of laboratory and imaging features required to identify and confirm these diseases is provided.

CONCLUSION

This systematic review shows that most differential diagnoses of psychosis should be considered in the case of a FEP and could be identified by providing a systematic checkup with a laboratory test that includes ammonemia, antinuclear and anti-NMDA antibodies, and HIV testing; brain magnetic resonance imaging and lumbar puncture should be considered according to the clinical presentation. Genetic research could be of interest to patients presenting with physical or developmental symptoms associated with psychiatric manifestations.

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.

Mutation of GPR143 Associated With Ocular Albinism Type 1, Intellectual Disability, and Schizophrenia: The Complex Biological and Social Interactions Between Genetic Syndromes and Mental Illness

Copy number variations, which manifest primarily as deletions and duplications, contribute significantly to the genetic risk of schizophrenia. Specific syndromes associated with copy number variations, exemplified by the 22q11 deletion syndrome, confer both congenital abnormalities and an elevated risk of schizophrenia. We report the case of a patient with a deletion of exons 2 through 8 of GPR143. In addition to having the ophthalmologic disorder ocular albinism type 1 (OA1), a well-established consequence of mutations of GPR143, the patient is also intellectually impaired and impulsive, and he developed schizophrenia at age 15. Psychiatric manifestations of OA1 have not previously been reported, yet remain plausible, as the GPR143 protein is widely distributed in the brain and may function as an L-DOPA receptor. However, the patient described here also had a family history of psychiatric disorders independent of OA1, in utero exposure to heroin and cocaine, and challenging family circumstances. We suggest that the relationship between his GPR143 mutation and his psychiatric disorders is complex. The mutation may have directly contributed to his cognitive and psychiatric disorders, but we also suspect that OA1, present in multiple family members, contributed to multigenerational familial instability. Further, OA1 likely exacerbated our patient's cognitive and social impairment by interfering with his education, while his neuropsychiatric status frequently interfered with the assessment and treatment of his OA1. We conclude that the psychiatric and nonpsychiatric manifestations of a genetic syndrome are best managed in parallel and that psychiatrists and other mental health providers may be in the best position to assure that patients receive appropriate genetic and medical care.

Alteration of brain nuclei in obese children with and without Prader-Willi syndrome

Introduction: Prader-Willi syndrome (PWS) is a multisystem genetic imprinting disorder mainly characterized by hyperphagia and childhood obesity. Extensive structural alterations are expected in PWS patients, and their influence on brain nuclei should be early and profound. To date, few studies have investigated brain nuclei in children with PWS, although functional and structural alterations of the cortex have been reported widely.

Methods: In the current study, we used T1-weighted magnetic resonance imaging to investigate alterations in brain nuclei by three automated analysis methods: shape analysis to evaluate the shape of 14 cerebral nuclei (bilateral thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, and nucleus accumbens), automated segmentation methods integrated in Freesurfer 7.2.0 to investigate the volume of hypothalamic subregions, and region of interest-based analysis to investigate the volume of deep cerebellar nuclei (DCN). Twelve age- and sex-matched children with PWS, 18 obese children without PWS (OB) and 18 healthy controls participated in this study.

Results: Compared with control and OB individuals, the PWS group exhibited significant atrophy in the bilateral thalamus, pallidum, hippocampus, amygdala, nucleus accumbens, right caudate, bilateral hypothalamus (left anterior-inferior, bilateral posterior, and bilateral tubular inferior subunits) and bilateral DCN (dentate, interposed, and fastigial nuclei), whereas no significant difference was found between the OB and control groups.

Discussion: Based on our evidence, we suggested that alterations in brain nuclei influenced by imprinted genes were associated with clinical manifestations of PWS, such as eating disorders, cognitive disability and endocrine abnormalities, which were distinct from the neural mechanisms of obese children.

Aripiprazole treatment for temper outbursts in Prader-Willi syndrome

Background

Prader–Willi syndrome (PWS) is a rare neurodevelopmental disorder based on a loss of paternally expressed genes in chromosome segment 15q11-13. Behavioral traits such as temper outbursts, stereotypic, and ritualistic behavior, as well as an increased risk of psychosis accompany the syndrome, representing a major issue in the treatment of adults with PWS. Up to now, no treatment guideline for these conditions in PWS exist. This study aimed to retrospectively analyze the effect and adverse effects of treatment with aripiprazole for temper outbursts in 10 adults with PWS.

Results

Aripiprazole was prescribed for temper outbursts (n = 10). Treatment outcome was assessed using the Clinical Global Impression-Severity (CGI-S) and -Improvement Scale (CGI-I).

Treatment success (CGI-I < 3) was observed in 70% of cases, with adverse effects from mild to partly serious extent in 60% of cases. The major adverse effect observed was increased daytime sleepiness. In total, 50% of the individuals were treated successfully for temper outbursts. The BMI did not change significantly in the successfully treated group after 6 months of treatment.

Conclusions

Aripiprazole can be a treatment option for temper outbursts in people with PWS. Although a high rate of side effects was detected, their severity led to discontinuation in only 20% of the cases. Furthermore, the absence of weight gain makes aripiprazole interesting especially for the PWS population.

Health Problems in Adults with Prader-Willi Syndrome of Different Genetic Subtypes: Cohort Study, Meta-Analysis and Review of the Literature

Prader−Willi syndrome (PWS) is a complex, rare genetic disorder caused by a loss of expression of paternally expressed genes on chromosome 15q11.2-q13. The most common underlying genotypes are paternal deletion (DEL) and maternal uniparental disomy (mUPD). DELs can be subdivided into type 1 (DEL-1) and (smaller) type 2 deletions (DEL-2). Most research has focused on behavioral, cognitive and psychological differences between the different genotypes. However, little is known about physical health problems in relation to genetic subtypes. In this cross-sectional study, we compare physical health problems and other clinical features among adults with PWS caused by DEL (N = 65, 12 DEL-1, 27 DEL-2) and mUPD (N = 65). A meta-analysis, including our own data, showed that BMI was 2.79 kg/m2 higher in adults with a DEL (p = 0.001). There were no significant differences between DEL-1 and DEL-2. Scoliosis was more prevalent among adults with a DEL (80% vs. 58%; p = 0.04). Psychotic episodes were more prevalent among adults with an mUPD (44% vs. 9%; p < 0.001). In conclusion, there were no significant differences in physical health outcomes between the genetic subtypes, apart from scoliosis and BMI. The differences in health problems, therefore, mainly apply to the psychological domain.

Recommendations for the diagnosis and management of childhood Prader-Willi syndrome in China

Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disease, which is caused by the lack of expression of paternally inherited imprinted genes on chromosome15q11.2-q13.1. The clinical manifestations of PWS vary with age. It is characterized by severe hypotonia with poor suck and feeding difficulties in the early infancy, followed by overeating in late infancy or early childhood and progressive development of morbid obesity unless the diet is externally controlled. Compared to Western PWS patients, Chinese patients have a higher ratio of deletion type. Although some rare disease networks, including PWS Cooperation Group of Rare Diseases Branch of Chinese Pediatric Society, Zhejiang Expert Group for PWS, were established recently, misdiagnosis, missed diagnosis and inappropriate intervention were usually noted in China. Therefore, there is an urgent need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy. Our purpose is to evaluate the current literature and evidences on diagnosis and management of PWS in order to provide evidence-based guidelines for this disease, specially from China.

The effects of dietary stachyose as prebiotic on immunity and anti-oxidant related genes’ expression and lipid metabolism in zebrafish ( Danio rerio )

An 8-week feeding trial was conducted to examine the efficacy of stachyose as a prebiotic on immune parameters, antioxidant-/immune-related genes’ expression, and lipid metabolism of zebrafish. Three hundred zebrafish (0.45 ± 0.08 g) were fed four diets containing different stachyose levels at 0, 1, 2 and 4 g kg-1, respectively. After eight weeks of the feeding trial, immunity, anti-oxidant defence and lipid metabolism were tested. It was observed that the addition of stachyose to the diet induced no significant influence (P>0.05) in SOD, GPX, and CAT, gene’s expression, compared to the control diet. The inclusion of stachyose resulted in no significant changes in immune gene expression (Lyz, IL-1, IL-6, and TNF) in zebrafish (P>0.05) compared to the control diet. Total cholesterol, triglyceride and LDL (low-density lipoprotein) significantly (P<0.05) decreased with the addition of 2 and 4 g kg-1 stachyose, while fish fed the control diet and 1 g.kg-1 recorded the highest significant value of LDL (P<0.05). Fish fed diet, either control or diet supplemented with 0.5 g kg-1 stachyose, recorded the lowest HDL value (P<0.05) compared to other treatments. In conclusion, stachyose can be potentially used as a feed additive to modulate lipid metabolism. However, this prebiotic couldn’t benefit immune parameters and anti-oxidant defence.

Hypomethylation of monoamine oxidase A promoter/exon 1 region is associated with temper outbursts in Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder caused by the absence of paternally expressed and maternally imprinted genes on chromosome 15q 11.2-13. It is associated with a certain behavioural phenotype, especially temper outbursts with verbal and physical aggression towards others. Recent studies show a promising therapeutic effect of serotonin reuptake inhibitors like sertraline on frequency and intensity of outbursts. Monoamine oxidase A (MAOA) (X p11.23) plays a crucial role in the metabolism of monoamines. Dysregulation in methylation of the CpG island spanning the promoter region and exon 1 of MAOA is implicated in impulsive and aggressive behaviour.

METHODS

In the present study, methylation rates of CpG dinucleotides in the MAOA promoter and exon 1 region were determined from DNA derived from whole blood samples of PWS patients (n = 32) and controls (n = 14) matched for age, sex and BMI via bisulfite sequencing. PWS patients were grouped into those showing temper outbursts, and those who do not.

RESULTS

Overall, PWS patients show a significant lower methylation rate at the promoter/exon 1 region than healthy controls in both sexes. Furthermore, PWS patients, male as well female with temper outbursts show a significant lower methylation rate than those without temper outbursts (p < 0.001 and p = 0.006).

CONCLUSION

The MAOA promoter/exon 1 region methylation seems to be dysregulated in PWS patients in sense of a hypomethylation, especially in those suffering from temper outbursts. This dysregulation probably plays a crucial role in the pathophysiology of temper outbursts in PWS.

Neurobehavioral Dimensions of Prader Willi Syndrome: Relationships Between Sleep and Psychosis-Risk Symptoms

Background

Prader Willi Syndrome (PWS) is a genetic disorder caused by the absence of expression of the paternal copies of maternally imprinted gene(s) located at 15q11-q13. While the physical and medical characteristics of PWS, including short stature, hyperphagia and endocrine dysfunction are well-characterized, systematic investigation of the long-recognized psychiatric manifestations has been recent.

Methods

Here, we report on the first remote (web-based) assessment of neurobehavioral traits, including psychosis-risk symptoms (Prodromal Questionnaire-Brief Version; PQ-B) and sleep behaviors (Pittsburgh Sleep Quality Index), in a cohort of 128 participants with PWS, of whom 48% had a paternal deletion, 36% uniparental disomy, 2.4% an imprinting mutation and 13% unknown mutation (mean age 19.3 years ± 8.4; 53.9% female). We aimed to identify the most informative variables that contribute to psychosis-risk symptoms. Multiple domains of cognition (accuracy and speed) were also assessed in a subset of PWS participants (n = 39) using the Penn Computerized Neurocognitive Battery (Penn-CNB).

Results

Individuals with PWS reported a range of psychosis-risk symptoms, with over half reporting cognitive disorganization (63.1%) and about one third reporting unusual beliefs (38.6%) and/or suspiciousness (33.3%). Subjectively-reported sleep quality, nap frequency, sleep duration, sleep disturbance, and daytime dysfunction were significant predictors of psychosis-risk symptom frequency and severity (all p's < 0.029). Sleep disturbance ratings were the strongest predictors of psychosis-risk symptoms. Regarding cognition, individuals with PWS showed the most prominent deficits in accuracy on measures of social cognition involving faces, namely Face Memory, Age Differentiation and Emotion Recognition, and greatest slowing on measures of Attention and Emotion Recognition. However, there were no significant differences in psychosis-risk symptoms or cognitive performance as a function of PWS genetic subtype.

Conclusions

PWS is associated with a high prevalence of distressing psychosis-risk symptoms, which are associated with sleep disturbance. Findings indicate that self/parent-reported neurobehavioral symptoms and cognition can be assessed remotely in individuals with PWS, which has implications for future large-scale investigations of rare neurogenetic disorders.

The paradox of Prader-Willi syndrome revisited: Making sense of the phenotype

Prader-Willi syndrome arises as a consequence of absent paternal copies of maternally imprinted genes at 15q11-13. Such gender-of-origin imprinted genes are expressed in the brain and also in mammalian placenta where paternally expressed imprinted genes drive foetal nutritional demand. We hypothesise that the PWS phenotype is the result of the genotype impacting two pathways: first, directly on brain development and secondly, on placental nutritional pathways that results in its down-regulation and relative foetal starvation. The early PWS phenotype establishes the basis for the later characteristic phenotype. Hyperphagia. and other phenotypic characteristics arise as a consequence of impaired hypothalamic development. Hypothalamic feeding pathways become set in a state indicative of starvation, with a high satiety threshold and a dysfunctional neurophysiological state due to incorrect representations of reward needs, based on inputs that indicate a false requirement for food. Our hypotheses, if confirmed, would lead to novel and effective interventions.

A Systematic Review of Unexplained Early Regression in Adolescents and Adults with Down Syndrome

A proportion of young people with Down syndrome (DS) experience unexplained regression that severely impacts on their daily lives. While this condition has been recognised by clinicians, there is a limited understanding of causation and an inconsistent approach to diagnosis and treatment. Varied symptomology and little knowledge of the cause of this regression have impacted on clinician's ability to prevent or manage this condition. The purpose of this review was to examine the current evidence surrounding unexplained regression in adolescents and young adults, and to establish patterns that may be of use to clinicians, as well as raising awareness of this condition. Four areas were specifically reviewed, (1) terminology used to refer to this condition, (2) the symptoms reported, (3) potential trigger events and, (4) treatments and prognosis. A variety of terminology is used for this condition, which has constrained past attempts to identify patterns. An extensive number of symptoms were reported, however sleep impairment, loss of language and distinct changes in personality and behaviour, such as disinterest and withdrawal, were among the most frequently seen. Life events that were tentatively associated with the onset of a regressive period included a significant change in environmental circumstances or a transition, such as moving home or leaving school. Prognosis for this condition is relatively positive with the majority of individuals making at least a partial recovery. However, few patients were found to make a full recovery to their previous level of functioning and serious adverse effects could persist in those who have made a partial recovery. This is an under-researched condition with significant impacts on people with DS and their families. There are no established treatments for this condition and there is relatively little recognition in the research community. Further studies that focus on the prevention and treatment of this condition with controlled treatment trials are needed.

Suicidality in individuals with Prader-Willi syndrome: a review of registry survey data

INTRODUCTION

Prader-Willi syndrome (PWS) is a rare, genetic, neurodevelopmental syndrome associated with hyperphagia and early onset obesity, growth and sex hormone insufficiencies, mild-to-moderate intellectual disability, and behavioral challenges such as compulsivity, anxiety, skin picking, social skills deficits and temper outbursts. Given high rates of psychiatric comorbidity and potential risk factors for suicide in PWS, this study sought a first estimate of the prevalence of suicidal ideation (SI) and attempts (SA) in the PWS population and any characteristics associated with suicidality in this population.

METHODS

Using the Global Prader-Willi Syndrome Registry, we included all participants who had answered a question about SI. We examined the most recent data from the surveys about social, economic, and demographic factors, genetic subtype, and psychiatric symptoms and treatments. A chi-square analysis was used to compare registry participants who reported SI to those without reported SI.

RESULTS

From 750 included survey respondents, 94 (12.5%) endorsed some history of SI. Of these, 25 (26.6%) also reported a history of SA, with an average age of 16.25 years at their first attempt. Those with a history of SI were predominantly male and adult age, and had higher rates of aggression and psychiatric comorbidities, therapies, and medications.

CONCLUSIONS

This study indicates that the rate of SI and SA in PWS is comparable to the general population, and that suicide attempts in PWS typically begin in middle-teenage years. Despite unique challenges, individuals with PWS and their caregivers should be included in screens and psychoeducation for suicide and mental health concerns.

Comparison of mouse models reveals a molecular distinction between psychotic illness in PWS and schizophrenia

Prader-Willi Syndrome (PWS) is a neurodevelopmental disorder caused by mutations affecting paternal chromosome 15q11-q13, and characterized by hypotonia, hyperphagia, impaired cognition, and behavioural problems. Psychotic illness is a challenging problem for individuals with PWS and has different rates of prevalence in distinct PWS genotypes. Previously, we demonstrated behavioural and cognitive endophenotypes of relevance to psychiatric illness in a mouse model for one of the associated PWS genotypes, namely PWS-IC, in which deletion of the imprinting centre leads to loss of paternally imprinted gene expression and over-expression of Ube3a. Here we examine the broader gene expression changes that are specific to the psychiatric endophenotypes seen in this model. To do this we compared the brain transcriptomic profile of the PWS-IC mouse to the PWS-cr model that carries a deletion of the PWS minimal critical interval spanning the snoRNA Snord116 and Ipw. Firstly, we examined the same behavioural and cognitive endophenotypes of relevance to psychiatric illness in the PWS-cr mice. Unlike the PWS-IC mice, PWS-cr exhibit no differences in locomotor activity, sensory-motor gating, and attention. RNA-seq analysis of neonatal whole brain tissue revealed a greater number of transcriptional changes between PWS-IC and wild-type littermates than between PWS-cr and wild-type littermates. Moreover, the differentially expressed genes in the PWS-IC brain were enriched for GWAS variants of episodes of psychotic illness but, interestingly, not schizophrenia. These data illustrate the molecular pathways that may underpin psychotic illness in PWS and have implications for potential therapeutic interventions.

Behavioural change in Prader-Willi syndrome during COVID-19 pandemic

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disorder that in many cases is associated with mental health disorders, in addition to characteristic symptoms such as hyperphagia. The current Sars-CoV-2 coronavirus pandemic has led to massive restrictions in health care and social life worldwide. People with PWS represent a particularly vulnerable population group to these restrictions, with unknown impact on their mental health.

METHODS

We conducted an online questionnaire to assess the impact of the restrictions associated with the COVID-19 pandemic on the mental health of people with PWS.

RESULTS

One hundred and eight caregivers completed the survey about individuals with PWS. Individuals with PWS > 6 years (n = 89) were included for evaluation with regard to psychopathological change. Respondents frequently reported an increase in psychopathological symptoms associated with PWS during the lockdown, with 51.7% reporting increased temper outbursts, 43.8% showing signs of sadness, 38.2% being anxious, 55.0% more irritable, and 39.3% showing more food seeking behaviour. Adjusted for the type of accommodation food seeking behaviour and irritability is increased to a significantly lesser extent in people with PWS accommodated in specialised care facilities compared with those living in their family home. No significant difference could be found between the sexes.

CONCLUSION

The COVID-19 pandemic has had a significant effect on the mental health of individuals with PWS, evidenced by an increase in behaviours associated with PWS, including temper outbursts, food-seeking, and irritability, which again underlines their need for specialised care. Individuals living with their families were particularly vulnerable, indicating that they and their families are in special need of support.

Sertraline as a treatment option for temper outbursts in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder caused by lack of the paternal copy of maternally imprinted, paternally expressed genes at the chromosome 15q11-13 region. In most cases, it is caused by a paternal deletion or a maternal disomy of chromosome 15. Behavioral problems with temper outbursts are common and often combined with physical aggressiveness and self-injury. They are the most frequent cause for a reduced quality of life in adulthood and represent a serious challenge for the individual and those surrounding the individual in everyday life. Until now, no promising pharmaceutical treatment option has been established, and only a few case reports on treatment with selective serotonin reuptake inhibitors (SSRIs) have been reported. In this case series, we investigated the effect of the SSRI sertraline in 14 individuals with PWS frequently showing severe temper outbursts with aggressiveness and self-injuries. After 6 months of treatment with sertraline, 13 of 14 patients (92.6%) either no longer displayed temper outbursts or showed a significant decrease in frequency and severity of temper outbursts. In one case, treatment was stopped due to severe sleep abnormalities. We conclude that sertraline is a promising and safe treatment option for severe temper outbursts in patients with PWS.

The Profiles and Correlates of Psychopathology in Adolescents and Adults with Williams, Fragile X and Prader-Willi Syndromes

Psychopathology is prevalent in Williams (WS), fragile X (FXS) and Prader–Willi (PWS) syndromes. However, little is known about the potential correlates of psychopathology in these groups. A questionnaire study was completed by 111 caregivers of individuals with WS (n = 35); FXS (n = 50) and PWS (n = 26). Mean age was 26 years (range 12–57 years); 74 (67%) were male. Multiple regression analyses indicated that higher rates of health problems and sensory impairments predicted higher psychopathology in WS (p < .0001). In PWS, poorer adaptive ability predicted higher overall psychiatric disturbance (p = .001), generalised anxiety (p = .006) and hyperactivity (p = .003). There were no significant predictors in FXS. This study highlights dissociations in the potential risk markers of psychopathology between genetic syndromes. Implications for intervention are discussed.

Prader-Willi syndrome imprinting centre deletion mice have impaired baseline and 5-HT2CR-mediated response inhibition

Prader–Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11–q13. In addition to endocrine and developmental issues, PWS presents with behavioural problems including stereotyped behaviour, impulsiveness and cognitive deficits. The PWS genetic interval contains several brain-expressed small nucleolar (sno) RNA species that are subject to genomic imprinting, including snord115 that negatively regulates post-transcriptional modification of the serotonin 2C receptor (5-HT_2CR) pre-mRNA potentially leading to a reduction in 5-HT_2CR function. Using the imprinting centre deletion mouse model for PWS (PWS^ICdel) we have previously shown impairments in a number of behaviours, some of which are abnormally sensitive to 5-HT_2CR-selective drugs. In the stop-signal reaction time task test of impulsivity, PWS^ICdel mice showed increased impulsivity relative to wild-type (WT) littermates. Challenge with the selective 5-HT_2CR agonist WAY163909 reduced impulsivity in PWS^ICdel mice but had no effect on WT behaviour. This behavioural dissociation in was also reflected in differential patterns of immunoreactivity of the immediate early gene c-Fos, with a blunted response to the drug in the orbitofrontal cortex of PWS^ICdel mice, but no difference in c-Fos activation in the nucleus accumbens. These findings suggest specific facets of response inhibition are impaired in PWS^ICdel mice and that abnormal 5-HT_2CR function may mediate this dissociation. These data have implications for our understanding of the aetiology of PWS-related behavioural traits and translational relevance for individuals with PWS who may seek to control appetite with the new obesity treatment 5-HT_2CR agonist lorcaserin.

Food and Non-Food-Related Behavior across Settings in Children with Prader-Willi Syndrome

This study sought to describe food- and non-food-related behaviors of children aged 3 to 18 years with Prader–Willi syndrome (PWS) in home and school settings, as assessed by 86 parents and 63 teachers using 7 subscales of the Global Assessment of Individual’s Behavior (GAIB). General Behavior Problem, Non-Food-Related Behavior Problem, and Non-Food-Related Obsessive Speech and Compulsive Behavior (OS/CB) scores did not differ significantly between parent and teacher reports. Food-Related Behavior Problem scores were higher in parent versus teacher reports when the mother had less than a college education (difference of 13.6 points, 95% Confidence Interval (CI) 5.1 to 22). Parents assigned higher Food-Related OS/CB scores than teachers (difference of 5.7 points, 95% CI 2.4 to 9.0). Although teachers reported fewer Food-Related OS/CB, they scored overall OS/CB higher for interfering with daily activities compared with parents (difference of 0.9 points, 95% CI 0.4 to 1.4). Understanding how behaviors manifest in home and school settings, and how they vary with socio-demographic and patient characteristics can help inform strategies to reduce behavior problems and improve outcomes.

Metabolic Parameters in Patients with Prader-Willi Syndrome and DiGeorge Syndrome with Respect to Psychopathological Manifestation

PURPOSE

The purpose of our study was to compare the metabolic parameters in two genetic syndromes with a proven high risk of developing psychiatric comorbidities. These comorbidities, especially mood and psychotic disorders, may be associated with a risk of obesity, type 2 diabetes and other components of metabolic syndrome regardless of antipsychotic treatment.

PATIENTS AND METHODS

Two groups of children diagnosed with Prader - Willi syndrome (PWS) (n = 20) and DiGeorge syndrome (DGS) (n = 18), aged 7-18 years, were enrolled. Behavioral symptoms and co-occurring psychopathological symptoms were assessed using the Child Behavior Checklist (CBCL). The levels of following biochemical parameters were measured: glucose, insulin, high-sensitivity C-reactive protein, total cholesterol, low- and high-density lipoproteins (LDL and HDL), triglycerides and non-HDL cholesterol. Additionally, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated.

RESULTS

There were significantly higher levels of insulin and non-HDL in patients with PWS compared to those with DGS. The scores of four CBCL subscales (social problems, thought problems, delinquent behavior and aggressive behavior) were significantly higher in PWS patients. Higher scores of the CBCL-thought problems were associated with significantly higher levels of insulin as well as HOMA-IR.

CONCLUSION

Patients with PWS seem to be more prone to develop subclinical metabolic dysregulation, in terms of elevated non-HDL levels and insulin levels, compared to DGS patients. Altered insulin sensitivity, present in both groups, even though it is not a specific risk factor, might be related to thought problems associated with psychosis.

Does SNORD116 mediate aspects of psychosis in Prader-Willi syndrome? Evidence from a non-clinical population

The paternally expressed gene SNORD116 encodes a set of short nucleolar RNAs that affect the expression of hundreds of other genes via epigenetic interactions. Lack of expression for SNORD116 has been implicated in major phenotypes of Prader-Willi Syndrome (PWS). Rates of psychosis and autism spectrum disorders are greatly increased in PWS, but the genetic and epigenetic causes of these increases remain unknown. We genotyped a large population of typical individuals for five SNPs within SNORD116 and phenotyped them for variation in schizotypal and autism spectrum traits. SNORD116 SNP and haplotype variation mediated variation exclusively in the Schizotypal Personality Questionnaire - Ideas of Reference subscale, which reflects variation in aspects of paranoia. The effect was restricted to females. SNORD116 represents, in addition to UBE3A and NDN-MAGEL2, a third, independent locus in the 15q11-q13 imprinted region that preferentially or exclusively affects levels of paranoia. This convergent pattern may reflect a common neural pathway affected by multiple genes, or an effect of interactions between the imprinted loci.

A profile of mental health and behaviour in Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a neurogenetic syndrome with an associated behavioural phenotype and a high incidence of behaviours of concern and psychiatric co-morbidity. These associated behaviours and co-morbidities are not well addressed by existing interventions, and they impact significantly on affected individuals and their caregivers.

METHODS

We undertook a national survey of the needs of individuals with PWS and their families in Ireland. In this paper, we report on the parent/caregiver-reported mental health, behavioural and access to services.

RESULTS

Over 50% of individuals with PWS in this survey had at least one reported psychiatric diagnosis, the most common diagnosis was anxiety. The most commonly reported behaviours in children were skin picking, repetitive questioning, difficulty transitioning and non-compliance. The same four behaviours were reported by caregivers as being the most commonly occurring in adolescents and adults in addition to food-seeking behaviours. Increased needs for mental health services were also reported by caregivers. Individuals with PWS had an average wait of 22 months for an appointment with a psychologist and 4 months for an appointment with a psychiatrist.

CONCLUSION

This study highlighted high levels of psychiatric co-morbidities and behavioural concerns in individuals with PWS in Ireland. The findings of this study suggest that there is an urgent need to provide specialist psychiatric and behavioural interventions to manage complex mental health and behavioural needs to better support individuals with PWS and reduce caregiver burden.

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

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

Improving access to genetic testing for adults with intellectual disability: A literature review and lessons from a quality improvement project in East London

Recent advances in genetic research have led to an increased focus on genetic causes of intellectual disability (ID) and have raised new questions about how and when clinicians offer genetic testing and the nature of communication around this decision with patients and carers. Determining the right approach to such discussions is complicated by complexities of communication, consent, and capacity and ethical concerns about genetic testing in this population. In this article, we briefly discuss the recent advances in genetic research relevant to people with intellectual disability, highlighting the challenges that might arise when undertaking genetic testing in this population. We then describe how we have used a Quality Improvement methodology to develop a clinical pathway for routine genetic testing for adults with intellectual disability in a clinical setting in East London.

[Psychological management of a patient with Prader Willi syndrome: case study of a young Moroccan girl]

Prader Willi syndrome is a rare genetic disease. Symptoms include binge eating disorder associated with the risk of morbid obesity, learning difficulties and behavioral problems or even major psychiatric disorders. The purpose of this case study is to conduct a literature review on Prader Willi syndrome and to highlight its impact on daily life, both on physical and mental health, as well as its management. We report the case of an 11-year old Moroccan girl presenting with Prader Willi syndrome. She was assisted in performing activities of daily living by using a comprehensive biopsychosocial approach which improved her quality of life. We here emphasize the primary and central role of the psychotherapist in the treatment of patients with Prader Willi syndrome which is based on counselling, motivational interviewing and cognitive behaviour therapy techniques. Prader Willi syndrome is a disease with severe psychiatric symptoms. Patient's care requires multidisciplinary team approach involving psychologist or psychiatrist.

Comparative psychopharmacology of autism and psychotic-affective disorders suggests new targets for treatment

The first treatments showing effectiveness for some psychiatric disorders, such as lithium for bipolar disorder and chlorpromazine for schizophrenia, were discovered by accident. Currently, psychiatric drug design is seen as a scientific enterprise, limited though it remains by the complexity of brain development and function. Relatively few novel and effective drugs have, however, been developed for many years. The purpose of this article is to demonstrate how evolutionary biology can provide a useful framework for psychiatric drug development. The framework is based on a diametrical nature of autism, compared with psychotic-affective disorders (mainly schizophrenia, bipolar disorder and depression). This paradigm follows from two inferences: (i) risks and phenotypes of human psychiatric disorders derive from phenotypes that have evolved along the human lineage and (ii) biological variation is bidirectional (e.g. higher vs lower, faster vs slower, etc.), such that dysregulation of psychological traits varies in two opposite ways. In this context, the author review the evidence salient to the hypothesis that autism and psychotic-affective disorders represent diametrical disorders in terms of current, proposed and potential psychopharmacological treatments. Studies of brain-derived neurotrophic factor, the PI3K pathway, the NMDA receptor, kynurenic acid metabolism, agmatine metabolism, levels of the endocannabinoid anandamide, antidepressants, anticonvulsants, antipsychotics, and other treatments, demonstrate evidence of diametric effects in autism spectrum disorders and phenotypes compared with psychotic-affective disorders and phenotypes. These findings yield insights into treatment mechanisms and the development of new pharmacological therapies, as well as providing an explanation for the longstanding puzzle of antagonism between epilepsy and psychosis. Lay Summary: Consideration of autism and schizophrenia as caused by opposite alterations to brain development and function leads to novel suggestions for pharmacological treatments.

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.

Genetic variation of UBE3A is associated with schizotypy in a population of typical individuals

The maternally expressed imprinted gene UBE3A has been implicated in autism, schizophrenia and psychosis. The phenotype of Angelman syndrome, caused by loss of UBE3A expression, involves autism spectrum traits, while Prader-Willi syndrome, where the genotype of maternal disomy increases dosage of UBE3A, shows high penetrance for the development of psychosis. Maternal duplications of the 15q11-q13 chromosome region that overlap the imprinted region also show an association with schizophrenia, further implying a connection between increased dosage of UBE3A and the development of schizophrenia and psychosis. We phenotyped a large population of typical individuals for autism spectrum and schizotypal traits and genotyped them for a set of SNPs in UBE3A. Genetic variation of rs732739, an intronic SNP tagging a large haplotype spanning nearly the entire range of UBE3A, was significantly associated with variation in total schizotypy. Our results provide an independent line of evidence, connecting the imprinted UBE3A gene to the schizophrenia spectrum.

Psychopathological disorders in Prader-Willi syndrome

Prader-Willi syndrome is a genetic disorder caused by chromosomal changes in segment 15q11-q13 including cognitive, mental, and behavioral symptoms, as well as a specific physical phenotype. Both the most common psychopathological changes (intellectual disability, obsessions, impulsivity, autism spectrum disorders, self-injuries) and the main psychiatric comorbidities (affective disorders, psychosis, obsessive-compulsive disorder, autism spectrum disorder) are characterized by a great heterogeneity, which warrants the need for better identification of their frequency and clinical signs. In addition to its effects on body compositionand hypotony, growth hormone has been shown to be useful for regulating patient behavior, and psychoactive drugs are also an option. Other alternatives have shown promising results in experimental trials. Adequate understanding of the psychopathology associated to Prader-Willi syndrome would allow for improving clinical approach, symptom identification, detection of comorbidities, and administration of more effective treatments, leading to better clinical outcomes.

Increased brain age in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is the most common genetic obesity syndrome, with associated learning difficulties, neuroendocrine deficits, and behavioural and psychiatric problems. As the life expectancy of individuals with PWS increases, there is concern that alterations in brain structure associated with the syndrome, as a direct result of absent expression of PWS genes, and its metabolic complications and hormonal deficits, might cause early onset of physiological and brain aging. In this study, a machine learning approach was used to predict brain age based on grey matter (GM) and white matter (WM) maps derived from structural neuroimaging data using T1-weighted magnetic resonance imaging (MRI) scans. Brain-predicted age difference (brain-PAD) scores, calculated as the difference between chronological age and brain-predicted age, are designed to reflect deviations from healthy brain aging, with higher brain-PAD scores indicating premature aging. Two separate adult cohorts underwent brain-predicted age calculation. The main cohort consisted of adults with PWS (n = 20; age mean 23.1 years, range 19.8-27.7; 70.0% male; body mass index (BMI) mean 30.1 kg/m2, 21.5-47.7; n = 19 paternal chromosome 15q11-13 deletion) and age- and sex-matched controls (n = 40; age 22.9 years, 19.6-29.0; 65.0% male; BMI 24.1 kg/m2, 19.2-34.2) adults (BMI PWS vs. control P = .002). Brain-PAD was significantly greater in PWS than controls (effect size mean ± SEM +7.24 ± 2.20 years [95% CI 2.83, 11.63], P = .002). Brain-PAD remained significantly greater in PWS than controls when restricting analysis to a sub-cohort matched for BMI consisting of n = 15 with PWS with BMI range 21.5-33.7 kg/m2, and n = 29 controls with BMI 21.7-34.2 kg/m2 (effect size +5.51 ± 2.56 years [95% CI 3.44, 10.38], P = .037). In the PWS group, brain-PAD scores were not associated with intelligence quotient (IQ), use of hormonal and psychotropic medications, nor severity of repetitive or disruptive behaviours. A 24.5 year old man (BMI 36.9 kg/m2) with PWS from a SNORD116 microdeletion also had increased brain PAD of 12.87 years, compared to 0.84 ± 6.52 years in a second control adult cohort (n = 95; age mean 34.0 years, range 19.9-55.5; 38.9% male; BMI 28.7 kg/m2, 19.1-43.1). This increase in brain-PAD in adults with PWS indicates abnormal brain structure that may reflect premature brain aging or abnormal brain development. The similar finding in a rare patient with a SNORD116 microdeletion implicates a potential causative role for this PWS region gene cluster in the structural brain abnormalities associated primarily with the syndrome and/or its complications. Further longitudinal neuroimaging studies are needed to clarify the natural history of this increase in brain age in PWS, its relationship with obesity, and whether similar findings are seen in those with PWS from maternal uniparental disomy.

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.

Clinical Usefulness of Aripiprazole Treatment in a Girl with Prader-Willi Syndrome and Psychosis

Prader-Willi syndrome (PWS) is a quite rare multi-systemic genetic disorder strongly associated with psychiatric illness in adults, especially psychosis. This report presents a 16-year-old female with PWS and symptoms of brief psychotic disorder with a complete resolution of symptoms under aripiprazole medication. However, an exacerbation occurred after aripiprazole reduction. Apart from a weight gain of about 2 kg over the course of two years, no adverse effects could be found. This first report on the use of aripiprazole in a subject with PWS and psychosis suggests that aripiprazole might be a promising treatment approach in this distinct group of patients.

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.

Mechanistic insights into the genetics of affective psychosis from Prader-Willi syndrome

Schizophrenia and bipolar disorder are common, severe, and disabling psychotic disorders, which are difficult to research. We argue that the genetically determined neurodevelopmental disorder Prader-Willi syndrome (PWS), which is associated with a high risk of affective psychotic illness, can provide a window into genetic mechanisms and associated neural pathways. People with PWS can all show non-psychotic psychopathology and problem behaviours, but the prevalence of psychotic illness differs markedly by genetic subtype; people with PWS due to chromosome 15 maternal uniparental disomy have higher prevalence of psychotic illness compared with patients with PWS due to 15q11-13 deletions of paternal origin. On the basis of this observation and the neural differences between genetic subtypes, we hypothesise that the combined effects of the absent expression of specific maternally imprinted genes at 15q11-13, and excess maternally imprinted or paternally expressed genes on chromosome 15, affect the γ-aminobutyric acid-glutamatergic pathways and associated neural networks that underpin mood regulation and sensory processing, resulting in psychotic illness. We propose a model of potential mechanisms of psychosis in PWS, which might be relevant in the general population, and should inform future research.

An overview of medical risk factors for childhood psychosis: Implications for research and treatment

OBJECTIVE

Psychotic disorders in childhood and early adolescence often progress to chronic schizophrenia, but in many cases there are diagnosable medical and genetic causes or risk factors. We reviewed our clinical experience and the relevant literature to identify these factors and to define their clinical features, appropriate work-up and treatment.

METHOD

We reviewed the results of comprehensive medical evaluations of 160 psychotic children and adolescents in our center. We also searched the Medline database (January 1994 to December 2015) with the following keywords and combinations: early onset schizophrenia, childhood onset schizophrenia, early onset psychosis, first episode psychosis, inborn errors of metabolism (IEM), genetic syndrome, copy number variants, autoimmune disorders, endocrine diseases, nutritional deficiencies, central nervous system infections, movement disorders, and epilepsy.

RESULTS

In our center, 12.5% of cases had medical disorders likely to be contributing to psychosis. Based on 66 relevant papers and our experience, we describe the clinical features of multiple genetic syndromes, IEM, and autoimmune, neurological, endocrinological and nutritional disorders that increase the risk of psychotic disorders in childhood and adolescence. We propose an algorithm for systematic laboratory evaluation, informed by clinical examination, emphasizing common and/or treatable factors.

CONCLUSIONS

In children and early adolescents with psychotic disorders, systematic medical work-up is warranted to identify medical and genetic factors. Not every rare cause can be worked up, thus careful clinical examinations are required to detect medical, neurological and genetic signs. Comprehensive medical evaluation can detect treatable diseases among cases of early-onset psychosis.

Brain-stem serotonin transporter availability in maternal uniparental disomy and deletion Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a rare condition because of the deletion of paternal chromosomal material (del PWS), or a maternal uniparental disomy (mUPD PWS), at 15q11-13. Affective psychosis is more prevalent in mUPD PWS. We investigated the relationship between the two PWS genetic variants and brain-stem serotonin transporter (5-HTT) availability in adult humans. Mean brain-stem 5-HTT availability determined by [123I]-beta-CIT single photon emission tomography was lower in eight adults with mUPD PWS compared with nine adults with del PWS (mean difference -0.93, t = -2.85, P = 0.014). Our findings confirm an association between PWS genotype and brain-stem 5-HTT availability, implicating a maternally expressed/paternally imprinted gene, that is likely to account for the difference in psychiatric phenotypes between the PWS variants. Declaration of interest None.

A model to characterize psychopathological features in adults with Prader-Willi syndrome

High prevalence of behavioral and psychiatric disorders in adults with Prader-Willi Syndrome (PWS) has been reported in last few years. However, data are confusing and often contradictory. In this article, we propose a model to achieve a better understanding of the psychopathological features in adults with PWS. The study is based on clinical observations of 150 adult inpatients, males and females. Non-parametric statistics were performed to analyse the association of psychopathological profiles with genotype, gender and age. We propose a model of psychiatric disorders in adults with PWS based on cognitive, emotional and behavioural issues. This model defines four psychopathological profiles: Basic, Impulsive, Compulsive, and Psychotic. The Basic profile is defined by traits and symptoms that are present in varying degrees in all persons with PWS. In our cohort, this Basic profile corresponds to 55% of the patients. The rest show, in addition to these characteristics, salient features of impulsivity (Impulsive profile, 19%), compulsivity (Compulsive profile, 7%), or psychosis (Psychotic profile, 19%). The analysis of factors associated with different profiles reveals an effect of genotype on Basic and Psychotic profiles (Deletion: 70% Basic, 9% Psychotic; Non-deletion: 23% Basic, 43% Psychotic) and a positive correlation between male sex and impulsivity, unmediated by sex hormone treatment. This is a clinical study, based on observation proposing an original model to understand the psychiatric and behavioural disorders in adults with PWS. Further studies are needed in order to test the validity of this model.

[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.

Psychiatric disorders in a cohort of individuals with Prader-Willi syndrome

BACKGROUND

Psychiatric manifestations in Prader-Willi Syndrome (PWS) are common and often are the most debilitating problem in these individuals. We present an epidemiological nation-wide survey of psychiatric diagnoses in the PWS population, based on full-range psychiatric interviews.

METHODS

We studied the distribution of psychiatric diagnoses (as opposed to a symptom-based approach) in the Israel national cohort of adolescents and adults with PWS. There was a total of 53 (32 males) ages 12 years and older. All individuals and their caretakers were interviewed using standardized psychiatric questionnaires. Demographic and clinical variables, Clinical Global Impression (CGI) score, IQ, severity of hyperphagia and quality of life (QOL) were also assessed and correlations with NPD (number of psychiatric diagnoses) calculated.

RESULTS

An overwhelming majority (89%) of the study participants had at least one psychiatric diagnosis. The most common were disruptive behavior disorders (DBD) (68%), obsessive compulsive disorder (OCD) (45%) and skin picking (35%). Individuals with DBD were at increased risk for OCD and skin picking. Psychotic disorders were found in 11%. NPD had a significant negative influence on QOL. There was no correlation between NPD and BMI, IQ, hyperphagia severity, hormonal profile or genetic subtypes.

CONCLUSIONS

Psychiatric diagnoses are very frequent in PWS and strongly influence QOL. Furthermore, characterizing the profile of psychiatric comorbidity in PWS is crucial for planning effective interventions. Precise behavioral phenotyping in PWS in combination with a well-defined genetic etiology may aid biological research linking biological correlates to behavior.

Prader-Willi syndrome mental health research strategy workshop proceedings: the state of the science and future directions

Abstract

This paper reports on the ‘Prader-Willi Syndrome (PWS) Mental Health Research Strategy Workshop’ that took place in March 2015. PWS is characterized by a complex phenotype affecting multiple systems with a high prevalence of maladaptive behaviours, and neuropsychiatric illness. Prader Willi syndrome results from the absence of paternally derived alleles located at the imprinted chromosomal locus, 15q11–13. The goal of the workshop was to highlight the state of the science of the mental health of people with this rare neurodevelopmental disorder. Mental ill health and maladaptive behaviors significantly impact quality of life for persons with PWS and their caregivers. Effective treatments and further research into this area are critically needed.

Methods

A multidisciplinary group of scientists and health care professionals were brought together to discuss the mental health and behavioral needs of people with PWS. The workshop strategy was to integrate established work on PWS with other relevant areas of study. The meeting also focused on two neurobiological systems that research had suggested were relevant to understanding the broader mental health aspects of PWS: the autonomic nervous system and oxytocin/vasopressin pathways. Other relevant topics were considered and recommendations made.

Results

The workshop presentations and working group discussions revealed that no one approach was sufficient to fully conceptualize the mental health challenges in PWS. Workshop discussions pointed to the need for theoretically informed studies focused on clinical characterization, measurement, and the probing of specific neurobiological systems through pharmaceutical or other interventions. Future studies in this area should explore the use of advanced neuroimaging protocols, as well as molecular studies using iPS cells in order to create more informed theories.

Conclusions

Within this framework, workshop participants identified and prioritized key research questions, and highlighted current opportunities. Recommendations were made with respect to the development of specific resources and tools for furthering mental health research such as The Global PWS Registry, the development of effective endpoints, the use of animal models and iPS cells to aid understanding of the neurobiological underpinnings. Additionally, collaborative opportunities across disciplines and syndromes were highlighted and targeted research initiatives focused on psychological/behavioral interventions modified for use in PWS were recommended.