A long-term population-based clinical and morbidity review of Prader-Willi syndrome in Western Australia

Prevalence and genotypic associations of epilepsy in Prader-Willi Syndrome: A systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence of epilepsy and febrile seizures and their association with genotype, i.e., 15q11-q13 deletions, uniparental chromosome 15 disomy (UPD) and other mutations, in the population with Prader-Willi syndrome (PWS).

METHODS

A systematic search of Medline, Scopus, Web of Science and the Cochrane Library was conducted. Studies estimating the prevalence of seizures, epilepsy and febrile seizures in the PWS population were included. Meta-analyses of the prevalence of epilepsy and febrile seizures and their association with genotype using the prevalence ratio (PR) were performed.

RESULTS

Fifteen studies were included. The prevalence of epilepsy was 0.11 (0.07, 0.15), similar to the prevalence of febrile seizures, with a prevalence of 0.09 (0.05, 0.13). The comparison "deletion vs. UPD" had a PR of 2.03 (0.90, 4.57) and 3.76 (1.54, 9.18) for epilepsy and febrile seizures.

CONCLUSIONS

The prevalence of seizure disorders in PWS is higher than in the general population. In addition, deletions in 15q11-q13 may be associated with a higher risk of seizure disorders. Therefore, active screening for seizure disorders in PWS should improve the lives of these people. In addition, genotype could be used to stratify risk, even for epilepsy, although more studies or larger sample sizes are needed.

A Comprehensive Review of Syndromic Forms of Obesity: Genetic Etiology, Clinical Features and Molecular Diagnosis

Syndromic obesity refers to obesity occurring with additional clinical findings, such as intellectual disability/developmental delay, dysmorphic features, and congenital malformations. PURPOSE OF REVIEW: To present a narrative review regarding the genetic etiology, clinical description, and molecular diagnosis of syndromic obesity, which is a rare condition with high phenotypic variability and genetic heterogeneity. The following syndromes are presented in this review: Prader-Willi, Bardet-Biedl, Pseudohypoparathyroidism, Alström, Smith-Magenis, Cohen, Temple, 1p36 deletion, 16p11.2 microdeletion, Kleefstra, SIM1-related, Börjeson-Forssman-Lehmann, WAGRO, Carpenter, MORM, and MYT1L-related syndromes. RECENT FINDINGS: There are three main groups of mechanisms for syndromic obesity: imprinting, transcriptional activity regulation, and cellular cilia function. For molecular diagnostic, methods of genome-wide investigation should be prioritized over sequencing of panels of syndromic obesity genes. In addition, we present novel syndromic conditions that need further delineation, but evidences suggest they have a higher frequency of obesity. The etiology of syndromic obesity tends to be linked to disrupted neurodevelopment (central) and is associated with a diversity of genes and biological pathways. In the genetic investigation of individuals with syndromic obesity, the possibility that the etiology of the syndromic condition is independent of obesity should be considered. The accurate genetic diagnosis impacts medical management, treatment, and prognosis, and allows proper genetic counseling.

Imprinting disorders

Imprinting disorders (ImpDis) are congenital conditions that are characterized by disturbances of genomic imprinting. The most common individual ImpDis are Prader-Willi syndrome, Angelman syndrome and Beckwith-Wiedemann syndrome. Individual ImpDis have similar clinical features, such as growth disturbances and developmental delay, but the disorders are heterogeneous and the key clinical manifestations are often non-specific, rendering diagnosis difficult. Four types of genomic and imprinting defect (ImpDef) affecting differentially methylated regions (DMRs) can cause ImpDis. These defects affect the monoallelic and parent-of-origin-specific expression of imprinted genes. The regulation within DMRs as well as their functional consequences are mainly unknown, but functional cross-talk between imprinted genes and functional pathways has been identified, giving insight into the pathophysiology of ImpDefs. Treatment of ImpDis is symptomatic. Targeted therapies are lacking owing to the rarity of these disorders; however, personalized treatments are in development. Understanding the underlying mechanisms of ImpDis, and improving diagnosis and treatment of these disorders, requires a multidisciplinary approach with input from patient representatives.

Do patients with Prader-Willi syndrome have favorable glucose metabolism?

Background

In recent years, more studies have observed that patients with Prader–Willi syndrome have lower insulin levels and lower insulin resistance than body mass index-matched controls, which may suggest protected glucose metabolism.

Method

The PubMed and Web of Science online databases were searched to identify relevant studies published in the English language using the terms “Prader–Willi syndrome” with “glucose”, “insulin”, “diabetes mellitus”, “fat”, “adipo*”, “ghrelin”, “oxytocin”, “irisin” or “autonomic nervous system”.

Results

The prevalence of impaired glucose intolerance, type 2 diabetes mellitus and some other obesity-associated complications in patients with Prader–Willi syndrome tends to be lower when compared to that in general obesity, which is consistent with the hypothetically protected glucose metabolism. Factors including adipose tissue, adiponectin, ghrelin, oxytocin, irisin, growth hormone and the autonomic nervous system possibly modulate insulin sensitivity in patients with Prader–Willi syndrome.

Conclusion

Although lower insulin levels, lower IR and protected glucose metabolism are widely reported in PWS patients, the causes are still mysterious. Based on existing knowledge, we cannot determine which factor is of utmost importance and what are the underlying mechanisms, and further research is in urgent need.

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

CONTEXT

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

OBJECTIVE

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

PATIENTS, DESIGN, AND SETTING

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

A retrospective analysis of the prevalence of imprinting disorders in Estonia from 1998 to 2016

Imprinting disorders (ImpDis) represent a small group of rare congenital diseases primarily affecting growth, development, and the hormonal and metabolic systems. The aim of present study was to identify the prevalence of the ImpDis in Estonia, to describe trends in the live birth prevalence of these disorders between 1998 and 2016, and to compare the results with previously published data. We retrospectively reviewed the records of all Estonian patients since 1998 with both molecularly and clinically diagnosed ImpDis. A prospective study was also conducted, in which all patients with clinical suspicion for an ImpDis were molecularly analyzed. Eighty-seven individuals with ImpDis were identified. Twenty-seven (31%) of them had Prader-Willi syndrome (PWS), 15 (17%) had Angelman syndrome (AS), 15 (17%) had Silver-Russell syndrome (SRS), 12 (14%) had Beckwith-Wiedemann syndrome (BWS), 10 (11%) had pseudo- or pseudopseudohypoparathyroidism, four had central precocious puberty, two had Temple syndrome, one had transient neonatal diabetes mellitus, and one had myoclonus-dystonia syndrome. One third of SRS and BWS cases fulfilled the diagnostic criteria for these disorders, but tested negative for genetic abnormalities. Seventy-six individuals were alive as of January 1, 2018, indicating the total prevalence of ImpDis in Estonia is 5.8/100,000 (95% CI 4.6/100,000-7.2/100,000). The minimum live birth prevalence of all ImpDis in Estonia in 2004-2016 was 1/3,462, PWS 1/13,599, AS 1/27,198, BWS 1/21,154, SRS 1/15,866, and PHP/PPHP 1/27,198. Our results are only partially consistent with previously published data. The worldwide prevalence of SRS and GNAS-gene-related ImpDis is likely underestimated and may be at least three times higher than expected.

Contributing factors of mortality in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a multi-system disorder resulting from a lack of paternal gene expression in the 15q11.2-q13 region. Using databases compiled through response questionnaires completed by families known to the Prader-Willi Syndrome Association (USA), this study tested the hypothesis that PWS genetic subtype, BMI, age of diagnosis, clinical symptoms, and growth hormone treatment differ among deceased and living individuals with PWS. Categorical and continuous variables were compared using chi-square and two-group t tests, respectively. Deceased individuals had higher rates of clinical features, including increased weight concerns, heart problems, sleep apnea, other respiratory complications, diabetes, osteoporosis, high pain tolerance, and severe skin picking, when compared to living individuals. Meanwhile, living individuals had higher rates of growth hormone use and early puberty. Obesity and subsequent consequences are the primary contributors to increased mortality in PWS. Additional emphasis on areas to decrease mortality is needed.

Disorders of Sleep and Ventilatory Control in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is an imprinted genetic disorder conferred by loss of paternal gene expression from chromosome 15q11.2-q13. Individuals with PWS have impairments in ventilatory control and are predisposed toward sleep disordered breathing due to a combination of characteristic craniofacial features, obesity, hypotonia, and hypothalamic dysfunction. Children with PWS progress from failure to thrive during infancy to hyperphagia and morbid obesity during later childhood and onward. Similarly, the phenotype of sleep disordered breathing in PWS patients also evolves over time from predominantly central sleep apnea in infants to obstructive sleep apnea (OSA) in older children. Behavioral difficulties are common and may make establishing effective therapy with continuous positive airway pressure (CPAP) more challenging when OSA persists after adenotonsillectomy. Excessive daytime sleepiness (EDS) is also common in patients with PWS and may continue after OSA is effectively treated. We describe here the characteristic ventilatory control deficits, sleep disordered breathing, and excessive daytime sleepiness seen in individuals with PWS. We review respiratory issues that may contribute to sudden death events in PWS patients during sleep and wakefulness. We also discuss therapeutic options for treating sleep disordered breathing including adenotonsillectomy, weight loss, and CPAP. Lastly, we discuss the benefits and safety considerations related to growth hormone therapy.

Adult Prader-Willi Syndrome: An Update on Management

With the advancement of medical care, the survival of most patients with syndromal genetic disease is greatly improved. In this case report, we have reported an adult Prader-Willi syndrome patient who is being diagnosed at the age of 33. The clinical features and their associated complications during adulthood have been reviewed.

"Over time it just becomes easier…": parents of people with Angelman syndrome and Prader-Willi syndrome speak about their carer role

PURPOSE

This study investigated two of the stresses experienced by parents caring for offspring with Angelman syndrome (AS) and Prader-Willi syndrome (PWS) in Western Australia, and identified their coping strategies.

METHODS

Parents of 19 offspring with AS and PWS participated in the Family Stress and Coping Interview which provides a stress level score, and a discussion of stressors and coping methods associated with 24 life situations, two of which are reported. All text was examined using directed content analysis.

RESULTS

Family carers (14/19) reported high stress associated with the initial diagnosis of AS or PWS in their offspring; and finding time for themselves. Stressors identified included lack of quality information about the disorder, time constraints and physical and emotional tiredness. Parents adopted a variety of coping strategies, including learning about the disorder, accepting the situation, seeking instrumental and social supports and dealing with problems.

CONCLUSIONS

No specific coping strategy was associated with reduced stress. However, parents felt that accurate and timely information during the diagnostic period helped. Parents used family and community support although there were difficulties accessing respite care. It is advised that government agencies, service providers, family members and peer support associations should provide practical and emotional support to assist the parents of offspring with AS and PWS, and indeed any form of intellectual disability, across the lifespan. Implications for Rehabilitation Long-term caring for offspring with AS or PWS can involve considerable stress for parents. Stress has been associated with poorer health outcomes for parental carers. Parents need a variety of practical and emotional supports to cope with stress, including timely access to information.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A disease specific questionnaire for assessing behavior in individuals with Prader-Willi syndrome

OBJECTIVE

Prader-Willi syndrome (PWS) is a genetic multisystem disorder with various medical, cognitive, behavioral and psychiatric problems. PWS is caused by the lack of expression of paternal genes on chromosome 15q2-q13 due to a deletion (70-75%), uniparental disomy (25-30%) or imprinting center defect (<5%). The common PWS behavioral and psychiatric characteristics are very typical in all ethnicities and were reported worldwide. Still, each individual has a specific profile of these common traits and the severity of his or her symptoms varies over time. Behavioral problems are the most important factor affecting the quality of life of both the individuals and their families. There is a need for a standardized tool to assess the specific behavioral profile of each individual and its present severity, in order to enable physicians to tailor the specific treatment needed and assist in a more accurate clinical follow up. To the best of our knowledge no such a tool has been standardized and published. We developed, based on the literature (mainly Forster and Gourash's paradigm) and our clinical experience, a 37 item disease specific questionnaire, the "PWS Behavioral Questionnaire" (PWSBQ) for assessing behavior in PWS patients. The purpose of the present study was to validate this tool in the entire adolescent and adult PWS population in Israel.

METHODS

The PWSBQ focuses on five major domains-abnormal emotional regulation, food-seeking related behavior, lack of flexibility, oppositional behavior and interpersonal problems and lastly body related behaviors. Caregivers of all Hebrew speaking individuals with PWS over the age of 12 years attending the Israeli national multidisciplinary PWS clinic were recruited. Of the 54 eligible individuals, 53 participated. They were interviewed with the PWSBQ and in addition filled the "Hyperphagia Questionnaire" and the "Child Behavioral Checklist" (CBCL). After verifying the questionnaire's content validity, all items on the PWSBQ were analyzed for internal reliability by calculating Cronbach's α. Criterion validity was evaluated by correlation testing with regard to the Hyperphagia Questionnaire and CBCL. In order to assess the questionnaire's interpretability, the correlation between the PWSBQ and the "Clinical Global Impression" (CGI) scores was evaluated.

RESULTS

The PWSBQ total score was positively correlated with both the CBCL total score and the CGI score (0.662 and 0.549, p<0.001 respectively). Of the five domains, four had acceptable internal reliability (excluding the body related behaviors domain, which was thus removed from the total score). Criterion validity was established for the four domains remaining in the statistical analysis (abnormal emotional regulation, food seeking related behavior, lack of flexibility and oppositional behavior and interpersonal problems).

CONCLUSIONS

Our findings suggest that the PWSBQ is a valid and reliable tool for the assessment of current behavioral problems among individuals with PWS. Although further research is needed in order to verify PWSBQ's ability to identify changes in the behavioral status of a given individual, it can now be used both in research and in a clinical setting, enabling the physician to plan the most suitable treatment based on the current behavioral status.

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

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

People with intellectual disability: what do we know about adulthood and life expectancy?

Increases in the life expectancy of people with Intellectual Disability have followed similar trends to those found in the general population. With the exception of people with severe and multiple disabilities or Down syndrome, the life expectancy of this group now closely approximates with that of the general population. Middle and old age, which until 30 years ago were not recognized in this population, are now important parts of the life course of these individuals. Older adults with Intellectual Disabilities form a small, but significant and growing proportion of older people in the community. How these persons grow older and how symptoms and complications of the underlying cause of the Intellectual Disability will influence their life expectancy is of the utmost importance.

The use of medical care and the prevalence of serious illness in an adult Prader-Willi syndrome cohort

INTRODUCTION

Adults with Prader-Willi syndrome (PWS) have an increased occurrence of several medical conditions. We report on the consequences of high morbidity rates such as prevalence rate of hospital admissions, medication use and surgery in a Dutch cohort of adults with PWS. Special attention is paid to causes and symptoms of serious illness.

METHOD

Participants were contacted via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with ID. The persons with PWS and their main caregivers were visited at home. Information was collected through semi-structured interviews on 102 adults with PWS.

RESULTS

The need for medical care in the neonatal period is associated with hypotonia and feeding problems. Hospital admissions for respiratory tract infections are frequent. During childhood most hospital admissions were due to PWS syndrome specific surgery. During adolescence hospital admissions occurred for scoliosis surgery and endocrine evaluations. At adult age, hospitalization was associated with inguinal hernia surgery, diabetes mellitus, psychosis, erysipelas, water and drug intoxications. In the older group, respiratory infections were again the main reason for hospital admissions. Frequently used medications at adult age included psychotropics, laxatives, anti-diabetics and dermatologic preparations. Abnormal drinking patterns, problems with anesthesia, decreased ability to vomit, abnormal pain awareness and unpredictable fever responses were frequent and often lead to delayed diagnoses of serious conditions.

DISCUSSION

People with PWS are frequent users of medical-care. Reasons for hospitalization and medication use are age specific. Knowledge on the different presentation of symptoms in people with PWS is needed. In case of unexplained illness, disturbances of consciousness and behavioral changes in people with PWS, an infection should be ruled out in the first place. Information from this study may help in preventing conditions and recognizing conditions in an early stage. Adequate preventive management and treatment of PWS related morbidity, could reduce medical care use in the long term and could improve quality adjusted life years.

Severe tooth wear in Prader-Willi syndrome. A case-control study

BACKGROUND

Prader-Willi syndrome (PWS) is a rare complex multsystemic genetic disorder characterized by severe neonatal hypotonia, endocrine disturbances, hyperphagia and obesity, mild mental retardation, learning disabilities, facial dysmorphology and oral abnormalities. The purpose of the present study was to explore the prevalence of tooth wear and possible risk factors in individuals with Prader-Willi syndrome.

METHODS

Forty-nine individuals (6-40 years) with PWS and an age- and sex-matched control group were included. Tooth wear was evaluated from dental casts and intraoral photographs and rated by four examiners using the Visual Erosion Dental Examination (VEDE) scoring system and the individual tooth wear index IA. In accordance with the VEDE scoring system, tooth wear was also evaluated clinically. Whole saliva was collected.

RESULTS

Mean VEDE score was 1.70 ± 1.44 in the PWS group and 0.46 ± 0.36 in the control group (p < 0.001). Median IA was 7.50 (2.60-30.70) in the PWS group and 2.60 (0.90-4.70) among controls (p < 0.001). In the PWS group tooth wear correlated significantly with age (VEDE; r = 0.79, p < 0.001, IA; r = 0.82, p < 0.001) and saliva secretion (VEDE; r = 0.46, p = 0.001, IA; r = 0.43, p = 0.002). Tooth grinding was also associated with tooth wear in the PWS group, as indicated by the mean VEDE 2.67 ± 1.62 in grinders and 1.14 ± 0.97 in non-grinders (p = 0.001) and median IA values 25.70 (5.48-68.55) in grinders and 5.70 (1.60-9.10) in non-grinders (p = 0.003). Multivariate linear regression analysis was performed with tooth wear as the dependent variable and PWS (yes/no), age, tooth grinding and saliva secretion as independent variables. PWS (yes/no), age and tooth grinding retained a significant association with tooth wear, VEDE (p < 0.001) and log IA (p < 0.001). The only factor significantly associated with tooth wear in the control group was age.

CONCLUSIONS

Our study provides evidence that tooth wear, in terms of both erosion and attrition, is a severe problem in Prader-Willi syndrome. There is therefore considerable need for prosthodontic rehabilitation in young adults with PWS.

Physical health problems in adults with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic disorder which is characterized by severe hypotonia and feeding problems in early infancy. In later childhood and adolescence, this is followed by hyperphagia and extreme obesity if the diet is not strictly controlled. Data on physical health problems in adults with PWS are scarce. We report on the prevalence of physical health problems in a Dutch cohort of adults with PWS in relation to age, BMI, and genetic subtype. Participants (n = 102) were retrieved via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with intellectual disabilities (ID). Details regarding physical health problem spanning the participants' lifespan were collected from caretakers through semi-structured interviews. Cardiovascular problems included diabetes mellitus, hypertension, and cerebrovascular accidents. Respiratory infections were frequent in adulthood. In males, cryptorchidism was almost universal, for which 28/48 males had a history of surgery, mostly orchidopexy. None of the women had a regular menstrual cycle. Sixteen individuals had a diagnosis of osteoporosis. Spinal deformation, hip dysplasia, and foot abnormalities were common. Skinpicking, leg edema, and erysipelas were frequent dermatological problems. The findings in our group support the notion that the prevalence of physical health problems is underestimated. This underscores the importance of developing monitoring programs which would help to recognize physical health problems at an early stage.

Systematic review of the clinical and genetic aspects of Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder that is caused by the lack of expression of paternally inherited imprinted genes on chromosome 15q11-q13. This syndrome has a characteristic phenotype including severe neonatal hypotonia, early-onset hyperphagia, development of morbid obesity, short stature, hypogonadism, learning disabilities, behavioral problems, and psychiatric problems. PWS is an example of a genetic condition caused by genomic imprinting. It can occur via 3 main mechanisms that lead to the absence of expression of paternally inherited genes in the 15q11.2-q13 region: paternal microdeletion, maternal uniparental disomy, and an imprinting defect. Over 99% of PWS cases can be diagnosed using DNA methylation analysis. Early diagnosis of PWS is important for effective long-term management. Growth hormone (GH) treatment improves the growth, physical phenotype, and body composition of patients with PWS. In recent years, GH treatment in infants has been shown to have beneficial effects on the growth and neurological development of patients diagnosed during infancy. There is a clear need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy in patients with PWS.

Epilepsy in Prader-Willi syndrome: clinical characteristics and correlation to genotype

Prader-Willi syndrome (PWS) is a genomic imprinting disease secondary to the loss of a functional paternal copy of 15q11-q13. Unlike its related imprinting disorder, Angelman syndrome, PWS has not been regarded as a risk factor for epilepsy. A retrospective analysis of 92 patients with PWS identified 24 (26%) with seizures. Twenty-two of these (92%) were affected by focal epilepsy and only two (8%) had generalized epilepsy. The most common seizure type was staring spells (67%). Correlation to genotype analysis showed deletions were more common in patients with epilepsy than in patients without epilepsy. The epilepsy syndromes were easy to control with a single antiepileptic drug in most cases. Three patients (11%) had had febrile seizures. These findings suggest that PWS may be a risk factor for epilepsy, which can manifest with focal features. Patients with PWS with a deletion genotype showed a trend toward developing seizures compared with patients with other genotypes in our series, even though this difference did not achieve statistical significance.

Nutritient intake of young children with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic disorder resulting in obesity. The diets for young children with PWS must balance the importance of preventing development of obesity with the need to supply sufficient energy and essential nutrients.

OBJECTIVE

To investigate the nutritional intake for children with PWS 2, 3, and 4 years of age and compare it with Nordic Nutritional Recommendations (NNR) and intake of healthy controls.

DESIGN

Assessments of food intake for six children 2-4 years of age were performed twice a year. At the age of 2 and 3 years data was obtained by using food recall interviews and at 4 year of age a pre-coded food-diary was used.

RESULTS

The energy intake for the 2-year-old children was 3.25 MJ/day (SD 0.85) and for the 3- and 4-year olds 3.62 MJ/day (SD 0.73) and 4.07 MJ/day (SD 0.39 MJ), respectively. These intakes are 61%, 68%, and 77% of the estimated energy requirements in NNR for healthy 2-, 3- and 4-year-old children, respectively, and 60% and 66% of the energy intakes of 2- and 4-year-old children in reference populations. The children's BMI-for-age score and length growth was within the normal range during the study period. The intake of fat was about 25 E% in all age groups and reduced when compared with reference populations. In 25% of the assessments the fat intake was 20 E% or below. The intake of iron was below recommendations in all age groups both with and without supplementation. The mean intake of vitamin D and tocopherol was below recommendations when intakes were determined excluding dietary supplementations.

CONCLUSIONS

More large-scale investigations on nutritional intake are needed to further investigate dietary challenges for this patient group.

French database of children and adolescents with Prader-Willi syndrome

Background

Prader-Willi syndrome (PWS) is a rare multisystem genetic disease leading to severe complications mainly related to obesity. We strongly lack information on the natural history of this complex disease and on what factors are involved in its evolution and its outcome. One of the objectives of the French reference centre for Prader-Willi syndrome set-up in 2004 was to set-up a database in order to make the inventory of Prader-Willi syndrome cases and initiate a national cohort study in the area covered by the centre.

Description

the database includes medical data of children and adolescents with Prader-Willi syndrome, details about their management, socio-demographic data on their families, psychological data and quality of life of the parents. The tools and organisation used to ensure data collection and data quality in respect of good clinical practice procedures are discussed, and main characteristics of our Prader-Willi population at inclusion are presented.

Conclusion

this database covering all the aspects of PWS clinical, psychological and social profiles, including familial psychological and quality of life will be a powerful tool for retrospective studies concerning this complex and multi factorial disease and could be a basis for the design of future prospective multicentric studies. The complete database and the Stata.do files are available to any researcher wishing to use them for non-commercial purposes and can be provided upon request to the corresponding author.

Quality of life assessment in a sample of patients affected by Prader-Willi syndrome

AIM

The goals of this study are to investigate the quality of life of Prader-Willi syndrome patients and to evaluate the relationship between quality of life and the clinical picture.

METHODS

We performed a multicentric study on 40 consecutive patients with Prader-Willi syndrome. Quality of life was evaluated through the Short Form-36 and the Child Health Questionnaire-Parent Form-50 according to the age of patients.

RESULTS

In patients older than 14 years old, quality of life is intensely impaired both in mental and physical aspects. Weight at the moment of the observation, birthweight and facial features are the main variables that influence quality of life. In patients who are 14 years old or younger, the Family Activity and Physical scores are lower for those patients with characteristic facial features and in patients with decreased fetal movement or infantile lethargy. Self-esteem is lower in patients with a higher Mini Mental Score.

CONCLUSIONS

Physical and mental aspects of quality of life are impaired in Prader-Willi patients, weight is the clinical finding which mainly influences negatively the physical aspects of quality of life. However, weight does not cause mental problems. These are mainly due to the presence of characteristic facial features. Interestingly, a high birthweight is associated with less impairment of the mental aspects of quality of life.

Childhood autism and associated comorbidities

Autism is a heterogeneous neurodevelopmental disorder with a variety of different etiologies, but with a heritability estimate of more than 90%. Although the strong correlation between autism and genetic factors has been long established, the exact genetic background of autism is still unclear. This review refers to all the genetic syndromes that have been described in children with pervasive developmental disorders (tuberous sclerosis, fragile X, Down, neurofibromatosis, Angelman, Prader-Willi, Gilles de la Tourette, Williams, etc.). Issues covered include prevalence and main characteristics of each syndrome, as well as the possible base of its association with autism in terms of contribution to the current knowledge on the etiology and genetic base of pervasive developmental disorders.

Prevalence of Angelman syndrome and Prader–Willi syndrome in Estonian children: Sister syndromes not equally represented

In 2000-2004, we performed a focused search for individuals with Angelman syndrome (AS) and Prader-Willi syndrome (PWS) aiming to establish the prevalence data for the individuals born between 1984 and 2004 in Estonia. All persons with probable AS or PWS (n = 184) were studied using the DNA methylation test. Individuals with abnormal methylation were all further tested by chromosomal and FISH analysis, and if necessary for uniparental disomy and UBE3A gene mutation. Nineteen cases with abnormal methylation test result were identified. Seven of them had AS, including six (85.7%) due to 15q11-13 deletion and one paternal UPD15. Twelve subjects had PWS: 4 (33%) 15q11-13 deletions, 6 (50%) maternal UPD15, 1 unbalanced chromosome 14;15 translocation resulting in a chromosome 15pter-q13 deletion, and 1 Robertsonian 15q;15q translocation. The minimum livebirth prevalence in 1984-2004 for AS was 1:52,181 (95% CI 1:25,326-1:1,29,785) and for PWS 1:30,439 (95% CI 1:17,425-1:58,908). The livebirth prevalence of AS and PWS increased within this period, but the change was statistically significant only for PWS (P = 0.032), from expected 1:88,495 (95% CI 1:24,390-1:3,22,580) to expected 1:12,547 (95% CI 1:540-1:29,154). Six individuals with AS and 11 with PWS were alive on the prevalence day (January 1, 2005), indicating the point prevalence proportion of 1:56,112 (95% CI 1:25,780-1:1,52,899) and 1:30,606 (95% CI 1:17,105-1:61,311), respectively. Our results showing the birth prevalence of AS 1.7 times less than PWS challenge the opinion that both syndromes are equally represented, and are in line with the view that mutations in sperm and oocytes occur at different frequencies.