Child and Adolescent Psychiatric Clinics of North America
Prader-Willi Syndrome: Medical Prevention and Behavioral Challenges
Section snippets
Genetics
Deletion or abnormal expression of paternal genes in chromosome 15q11-13 can result in the Prader-Willi phenotype. Complete or partial deletion of paternal 15q11-q13 accounts for 70% of affected patients, whereas approximately 25% have uniparental maternal disomy (UPD). In normal chromosome pairs, each chromosome is derived from a different parent. The term “uniparental disomy” indicates that both copies of a particular chromosome derive from only one of the parents. Inheriting both copies of
Medical considerations
Medical problems are inherent within the clinical diagnostic criteria of PWS and differ according to the stage of life [7]. Perinatally, the manifestations are difficult delivery, central hypotonia, poor sucking, motor delay, and failure to thrive, which often necessitate special feeding techniques such as nasogastric tubes. The characteristic dysmorphic features include dolichocephaly and almond-shaped eyes. Small mouth, hands, and feet, speech articulation defects, and a distinct prosody
Endocrine disorders and hormonal treatment
Children who have PWS show variable degrees of impaired growth hormone (GH) secretion along with low levels of serum insulin and insulin-like growth factors. If untreated, 50% of individuals who have PWS fail to reach a normal adult height. GH treatment of these children results in a significant and persistent increase in height velocity and height standard deviation scores [14].
Beyond increasing final height, GH has other important beneficial effects in patients who have PWS. Infants in whom
Cognition
Mental retardation is a major characteristic of PWS. In a meta-analysis of 575 people who have PWS, only 5% were of normal intelligence, one third were found to be moderately retarded, and most were in the borderline mildly retarded range. No IQ decline was seen with age [21]. Unfortunately, their immature social behavior often masks their intellectual abilities [22].
A pattern of cognitive strengths and weaknesses is apparent, although not all individuals who have PWS show this profile [21]. As
Behavioral characteristics and psychiatric issues in Prader-Willi syndrome
Behavioral patterns are remarkably consistent among persons who have PWS, albeit with a wide spectrum of intensity and frequency. The characteristic symptom complex is often termed “the behavioral phenotype of PWS,” which qualifies persons who have PWS for an Axis I diagnosis of “personality change due to a medical condition” [29]. Forster and Gourash [30] suggested a useful classification in domains that we have modified in accordance with our clinical experience.
Comorbid psychiatric disorders
Levels of psychopathology are found to be higher among persons who have PWS than among persons with intellectual disability of other origins [42]. Attention deficit hyperactivity disorder and obsessive-compulsive disorder already have been discussed, and this section focuses on mood and psychotic disorders.
Sudden bursts of disturbed mood, as part of the “normal” behavioral pattern in PWS, are generally trigger-dependent and short lived. During adolescence, prolonged waves of restlessness and
Psychopharmacology
The therapeutic and side effects of medications in patients who have PWS often can be greater than expected, even in severely obese patients who receive low dosages when considering their body weight. For many patients, one fourth to one half of the normally prescribed dose is sufficient, whereas usual dosage levels may cause toxic reactions or exacerbation of behavior problems [9]. Severely reduced metabolism by some components of cytochrome 450, a metabolic abnormality documented in one third
Behavioral and institutional treatment
Managing behaviors of people who have PWS can be successful in the long-term if a comprehensive and consistent approach is implemented [9], [47]. The treatment should focus on food- and non–food-related behaviors. As for the food-related issues, the most basic aspect of any program is having all food under lock and key and granting no access without parental or staff supervision. It is critical that all food-related activities be structured and consistent, including meal times, the particular
The multidisciplinary approach
The complexity of the clinical problems in patients who have PWS requires an approach that integrates the different professional fields involved. The PWS multidisciplinary clinic at our institution is one model of integrated care. The clinic staff includes specialists in pediatric neurology, child psychiatry, endocrinology, psychology, orthopedics, and nutrition during a single clinic visit. Consultations with pulmonary and ear, nose, and throat physicians who are familiar with PWS are obtained
Acknowledgments
The authors are deeply grateful to Professor Ruth Shalev for her thoughtful comments and suggestions in revising the manuscript.
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Nutrition for children with special health care needs
2017, Nutrition in the Prevention and Treatment of DiseaseQuality of life in children with Prader Willi Syndrome: Parent and child reports
2016, Research in Developmental DisabilitiesCitation Excerpt :A comprehensive approach to the treatment of PWS is often recommended including parent education, growth hormone replacement therapy, physical activity and diet (Cassidy & Driscoll, 2009). Beyond the treatment of the disorder, there is a growing awareness of the need for improving the quality of life of individuals with PWS (Benarroch, Hirsch, Genstil, Landau, & Gross-Tsur, 2007). Previous research has demonstrated that physical and mental aspects of quality of life are lower in individuals with PWS than in a healthy population (Caliandro et al., 2007).
The Central Role of Etiology in Science and Practice in Intellectual Disability
2016, International Review of Research in Developmental DisabilitiesCitation Excerpt :In addition to areas of challenge in cognitive-linguistic functioning outlined earlier, individuals with neurogenetic disorders also often have pronounced difficulties with areas of motor development, adaptive functioning, communication, and social functioning. Several neurogenetic disorders including DS, PWS, and AS demonstrate motor development challenges, often related to hypotonia (Benarroch, Hirsch, Genstil, Landau, & Gross-Tsur, 2007; de Campos, Rocha, & Savelsbergh, 2010; Dan, 2009; Fidler, Hepburn, et al., 2011; Harris & Shea, 1991). Social behavior is another domain that is affected in the presence of neurogenetic disorders associated with ID.
A disease specific questionnaire for assessing behavior in individuals with Prader-Willi syndrome
2015, Comprehensive PsychiatryCitation Excerpt :The more maladaptive the behavior, the higher the stress levels in the patient's family, while other parameters as patient's age, IQ and level of obesity seem to have no correlation with the levels of stress [26]. These data emphasize the clinical need to identify the specific behavioral and emotional characteristics of each patient and outline behavioral and medical treatment thereby improving both the patient's and the family's QoL [9]. Despite the need for an accurate and specific tool to characterize the behavioral and emotional phenotype in PWS, there is no validated assessment tool.
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This study was supported in part by grants from the Peretz Naftali Foundation and the Mirsky Foundation.