Prader-Willi Research Articles

Angelman and Prader-Willi Syndromes: Sister Imprinting Disorders With High Complication Rates Following Spinal Deformity Surgery.

We sought to examine the modern surgical treatment of spinal deformity associated with sister imprinting disorders, Prader-Willi syndrome (PWS) and Angelman syndrome (AS), with emphasis on the specific complications encountered in these patient populations. Fifteen patients with PWS and 5 patients with AS who underwent surgical intervention for spinal deformity between 2000 and 2018 were identified. Postoperative complications were classified using the modified Clavien-Dindo-Sink (CDS) system and further categorized into specific subtypes including excessive drainage, dehiscence, implant failure, infection, and delayed wound healing. Perioperative and final follow-up radiographic data were analyzed. Mean age at surgery was 12.9 years (range, 4-21 years) with mean follow-up of 46.1 months (range, 1-145 months). There were postoperative complications in 17 patients (85%). Ten major complications (CDS ≥ 3) occurred in 9 patients (45%). These included 5 infections requiring reoperation, 1 seroma requiring drainage, 2 severe cervical-thoracic deformities requiring reoperation, 1 implant failure requiring reoperation, and 1 death secondary to fungal sepsis and thromboembolic disease. Eight additional patients (40%) had minor complications (CDS 1 or 2). Eight intraoperative complications occurred in 5 patients (25%), including loss of neuromonitoring signals and cerebrospinal fluid leaks. Surgical intervention for scoliosis in PWS and AS continues to have high complication rates secondary to medical and behavioral comorbidities found in these patient populations. The exact etiology of the high complication rates encountered cannot be definitively stated, but both syndromes frequently present with a number of unique features that may predispose patients to develop surgical complications. [Orthopedics. 2023;46(4):e223-e229.].

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

ABSTRACT 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.

Effects of early recombinant human growth hormone treatment in young Chinese children with Prader–Willi syndrome

BackgroundPrader–Willi syndrome (PWS) is a rare and multisystemic genetic disorder that is characterized by severe hypotonia, hyperphagia, short stature, and global developmental delay. Although early recombinant human growth hormone (rhGH) treatment has been proven to rescue some symptoms and bring additional benefits to PWS patients, studies in patients under 2 years old are scarce. Thus, this study aims to investigate the effectiveness and safety of rhGH treatment for young children.MethodsA total of 96 genetically confirmed Chinese PWS infants or toddlers (47 males) followed between 2013 and 2022 were retrospectively analyzed. Sixty-five infants (early treatment group) started rhGH treatment during their first year, and 31 toddlers (later treatment group) started at the age of 1–2 years. Auxological parameters, carbohydrate metabolism parameters, thyroid function, liver function, insulin-like growth factor-1 (IGF-1), and radiographs were acquired before the initiation of the treatment and every 3–6 months thereafter. Height/length, weight, and weight for height were expressed as standard deviation scores (SDSs) according to WHO child growth standards.ResultsThe mean SDS of length/height in the early treatment group was significantly higher than that in the later treatment group throughout the observation period (all P < 0.001). The change in the length SDS between the two groups at 1 year old and 4 years old was 1.50 (95% CI, 0.88–2.13) and 0.63 (95% CI, 0.16–1.10), respectively. Compared to the later treatment group, the weight SDS in the early treatment group increased by 0.94 (95% CI, 0.37–1.52) at 1 year old and 0.84 (95% CI, 0.28–1.39) at 2 years old. No statistical significance was found after 2.5 years of age. No significant differences were observed in IGF-1, incidence of liver dysfunction, hypothyroidism or spinal deformity between the two groups.ConclusionsrhGH treatment improved growth and body composition in infants and toddlers. Furthermore, an early start of rhGH treatment is expected to have more efficacy than the later treatment group without an increase in adverse effects.

In Silico Examination of Single Nucleotide Missense Mutations in NHLH2, a Gene Linked to Infertility and Obesity

Continual advances in our understanding of the human genome have led to exponential increases in known single nucleotide variants. The characterization of each of the variants lags behind. For researchers needing to study a single gene, or multiple genes in a pathway, there must be ways to narrow down pathogenic variants from those that are silent or pose less pathogenicity. In this study, we use the NHLH2 gene which encodes the nescient helix-loop-helix 2 (Nhlh2) transcription factor in a systematic analysis of all missense mutations to date in the gene. The NHLH2 gene was first described in 1992. Knockout mice created in 1997 indicated a role for this protein in body weight control, puberty, and fertility, as well as the motivation for sex and exercise. Only recently have human carriers of NHLH2 missense variants been characterized. Over 300 missense variants for the NHLH2 gene are listed in the NCBI single nucleotide polymorphism database (dbSNP). Using in silico tools, predicted pathogenicity of the variants narrowed the missense variants to 37 which were predicted to affect NHLH2 function. These 37 variants cluster around the basic-helix-loop-helix and DNA binding domains of the transcription factor, and further analysis using in silico tools provided 21 SNV resulting in 22 amino acid changes for future wet lab analysis. The tools used, findings, and predictions for the variants are discussed considering the known function of the NHLH2 transcription factor. Overall use of these in silico tools and analysis of these data contribute to our knowledge of a protein which is both involved in the human genetic syndrome, Prader-Willi syndrome, and in controlling genes involved in body weight control, fertility, puberty, and behavior in the general population, and may provide a systematic methodology for others to characterize variants for their gene of interest.

Prader-Willi syndrome: Symptoms and topiramate response in light of genetics.

Prader-Willi Syndrome (PWS) is a rare genetic condition, which affects one in 25,000 births and results in various phenotypes. It leads to a wide range of metabolic and endocrine disorders including growth delay, hypogonadism, narcolepsy, lack of satiety and compulsive eating, associated with mild to moderate cognitive impairment. Prognosis is especially determined by the complications of obesity (diabetes, cardiorespiratory diseases) and by severe behavioral disorders marked by impulsivity and compulsion. This heterogeneous clinical picture may lead to mis- or delayed diagnosis of comorbidities. Moreover, when diagnosis is made, treatment remains limited, with high interindividual differences in drug response. This may be due to the underlying genetic variability of the syndrome, which can involve several different genetic mutations, notably deletion or uniparental disomy (UPD) in a region of chromosome 15. Here, we propose to determine whether subjects with PWS differ for clinical phenotype and treatment response depending on the underlying genetic anomaly. We retrospectively included all 24 PWS patients who were referred to the Reference Center for Rare Psychiatric Disorders (GHU Paris Psychiatrie and Neurosciences) between November 2018 and July 2022, with either deletion (N = 8) or disomy (N = 16). The following socio-demographic and clinical characteristics were recorded: age, sex, psychiatric and non-psychiatric symptoms, the type of genetic defect, medication and treatment response to topiramate, which was evaluated in terms of eating compulsions and impulsive behaviors. We compared topiramate treatment doses and responses between PWS with deletion and those with disomy. Non-parametric tests were used with random permutations for p-value and bootstrap 95% confidence interval computations. First, we found that disomy was associated with a more severe clinical phenotype than deletion. Second, we observed that topiramate was less effective and less tolerated in disomy, compared to deletion. These results suggest that a pharmacogenomic-based approach may be relevant for the treatment of compulsions in PWS, thus highlighting the importance of personalized medicine for such complex heterogeneous disorders.

The diagnosis and treatment of Prader-Willi syndrome

Prader-Willi综合征是由于父源染色体15q11.2-q13.1区域缺失或印记基因的功能缺陷所致的印记遗传病，为一种较常见的罕见病。早期以肌张力减低和喂养困难，幼儿期后以肥胖、性发育不良和智力发育迟缓为主要临床特征。.

An Exploratory Analysis on the 2D:4D Digit Ratio and Its Relationship with Social Responsiveness in Adults with Prader-Willi Syndrome.

Prader-Willi syndrome (PWS) is a genetic disorder produced by a lack of expression of paternally derived genes in the 15q11-13 region. Research has generally focused on its genetic and behavioral expression, but only a few studies have examined epigenetic influences. Prenatal testosterone or the maternal testosterone-to-estradiol ratio (MaTtEr) has been suggested to play an important role in the development of the 'social brain' during pregnancy. Some studies propose the 2D:4D digit ratio of the hand as an indirect MaTtEr measure. The relationship between social performance and MaTtEr has been studied in other neurodevelopmental conditions such as Autism Spectrum Disorder (ASD), but to our best knowledge, it has never been studied in PWS. Therefore, our study aims to clarify the possible existence of a relationship between social performance-as measured using the Social Responsiveness Scale (SRS)-and MaTtEr levels using the 2D:4D ratio. We found that, as a group, PWS individuals have shorter index and ring fingers than the control group, but no significant difference in the 2D:4D ratios. The 2D:4D ratio showed a correlation only with Restricted Interests and Repetitive Behavior Subscale, where a positive correlation only for male individuals with PWS was found. Considering only PWS with previous GH treatment during childhood/adolescence (PWS-GH), index and ring fingers did not show differences in length with the control group, but the 2D:4D ratio was significantly higher in the right or dominant hand compared to controls.

Progress in Brain Magnetic Resonance Imaging of Individuals with Prader-Willi Syndrome.

Prader-Willi syndrome (PWS), a rare epigenetic disease mapping the imprinted chromosomal domain of 15q11.2-q13.3, manifests a regular neurodevelopmental trajectory in different phases. The current multimodal magnetic resonance imaging (MRI) approach for PWS focues on morphological MRI (mMRI), diffusion MRI (dMRI) and functional MRI (fMRI) to uncover brain alterations. This technique offers another perspective to understand potential neurodevelopmental and neuropathological processes of PWS, in addition to specific molecular gene expression patterns, various clinical manifestations and metabolic phenotypes. Multimodal MRI studies of PWS patients demonstrated common brain changes in the volume of gray matter, the integrity of the fiber tracts and the activation and connectivity of some networks. These findings mainly showed that brain alterations in the frontal reward circuit and limbic system were related to molecular genetics and clinical manifestations (e.g., overwhelming eating, obsessive compulsive behaviors and skin picking). Further exploration using a large sample size and advanced MRI technologies, combined with artificial intelligence algorithms, will be the main research direction to study the structural and functional changes and potential pathogenesis of PWS.

The Long Way of Oxytocin from the Uterus to the Heart in 70 Years from Its Discovery.

The research program on oxytocin started in 1895, when Oliver and Schafer reported that a substance extracted from the pituitary gland elevates blood pressure when injected intravenously into dogs. Dale later reported that a neurohypophysial substance triggers uterine contraction, lactation, and antidiuresis. Purification of this pituitary gland extracts revealed that the vasopressor and antidiuretic activity could be attributed to vasopressin, while uterotonic and lactation activity could be attributed to oxytocin. In 1950, the amino-acid sequences of vasopressin and oxytocin were determined and chemically synthesized. Vasopressin (CYFQNCPRG-NH2) and oxytocin (CYIQNCPLG-NH2) differ by two amino acids and have a disulfide bridge between the cysteine residues at position one and six conserved in all vasopressin/oxytocin-type peptides. This characterization of oxytocin led to the Nobel Prize awarded in 1955 to Vincent du Vigneaud. Nevertheless, it was only 50 years later when the evidence that mice depleted of oxytocin or its receptor develop late-onset obesity and metabolic syndrome established that oxytocin regulates energy and metabolism. Oxytocin is anorexigenic and regulates the lean/fat mass composition in skeletal muscle. Oxytocin's effect on muscle is mediated by thermogenesis via a pathway initiated in the myocardium. Oxytocin involvement in thermogenesis and muscle contraction is linked to Prader-Willi syndrome in humans, opening exciting therapeutic avenues.

Clinical Trials in Prader-Willi Syndrome: A Review.

Prader-Willi syndrome (PWS) is a complex, genetic, neurodevelopmental disorder. PWS has three molecular genetic classes. The most common defect is due to a paternal 15q11-q13 deletion observed in about 60% of individuals. This is followed by maternal disomy 15 (both 15 s from the mother), found in approximately 35% of cases. the remaining individuals have a defect of the imprinting center that controls the activity of imprinted genes on chromosome 15. Mild cognitive impairment and behavior problems in PWS include self-injury, anxiety, compulsions, and outbursts in childhood, impacted by genetic subtypes. Food seeking and hyperphagia can lead to morbid obesity and contribute to diabetes and cardiovascular or orthopedic problems. The control of hyperphagia and improving food-related behaviors are the most important unmet needs in PWS and could be addressed with the development of a new therapeutic agent, as currently no approved therapeutics exist for PWS treatment. The status of clinical trials with existing results for the management of obesity and hyperphagia in PWS will be discussed in this review, including treatments such as beloranib, setmelanotide, a diazoxide choline controlled-release tablet (DCCR), an unacylated ghrelin analogue, oxytocin and related compounds, glucagon-like peptide 1 receptor agonists, surgical intervention, and transcranial direct-current stimulation.

Building Blocks for Deep Phenotyping in Infancy: A Use Case Comparing Spontaneous Neuromotor Functions in Prader-Willi Syndrome and Cerebral Palsy.

With the increasing worldwide application of the Prechtl general movements assessment (GMA) beyond its original field of the early prediction of cerebral palsy (CP), substantial knowledge has been gained on early neuromotor repertoires across a broad spectrum of diagnostic groups. Here, we aimed to profile the neuromotor functions of infants with Prader-Willi syndrome (PWS) and to compare them with two other matched groups. One group included infants with CP; the other included patients who were treated at the same clinic and turned out to have inconspicuous developmental outcomes (IOs). The detailed GMA, i.e., the motor optimality score-revised (MOS-R), was used to prospectively assess the infants' (N = 54) movements. We underwent cross-condition comparisons to characterise both within-group similarities and variations and between-group distinctions and overlaps in infants' neuromotor functions. Although infants in both the PWS and the CP groups scored similarly low on MOS-R, their motor patterns were different. Frog-leg and mantis-hand postures were frequently seen in the PWS group. However, a PWS-specific general movements pattern was not observed. We highlight that pursuing in-depth knowledge within and beyond the motor domain in different groups has the potential to better understand different conditions, improve accurate diagnosis and individualised therapy, and contribute to deep phenotyping for precision medicine.

PHIP-associated Chung-Jansen syndrome: Report of 23 new individuals.

In 2016 and 2018, Chung, Jansen and others described a new syndrome caused by haploinsufficiency of PHIP (pleckstrin homology domain interacting protein, OMIM *612,870) and mainly characterized by developmental delay (DD), learning difficulties/intellectual disability (ID), behavioral abnormalities, facial dysmorphism and obesity (CHUJANS, OMIM #617991). So far, PHIP alterations appear to be a rare cause of DD/ID. "Omics" technologies such as exome sequencing or array analyses have led to the identification of distinct types of alterations of PHIP, including, truncating variants, missense substitutions, splice variants and large deletions encompassing portions of the gene or the entire gene as well as adjacent genomic regions. We collected clinical and genetic data of 23 individuals with PHIP-associated Chung-Jansen syndrome (CHUJANS) from all over Europe. Follow-up investigations (e.g. Sanger sequencing, qPCR or Fluorescence-in-situ-Hybridization) and segregation analysis showed either de novo occurrence or inheritance from an also (mildly) affected parent. In accordance with previously described patients, almost all individuals reported here show developmental delay (22/23), learning disability or ID (22/23), behavioral abnormalities (20/23), weight problems (13/23) and characteristic craniofacial features (i.e. large ears/earlobes, prominent eyebrows, anteverted nares and long philtrum (23/23)). To further investigate the facial gestalt of individuals with CHUJANS, we performed facial analysis using the GestaltMatcher approach. By this, we could establish that PHIP patients are indistinguishable based on the type of PHIP alteration (e.g. missense, loss-of-function, splice site) but show a significant difference to the average face of healthy individuals as well as to individuals with Prader-Willi syndrome (PWS, OMIM #176270) or with a CUL4B-alteration (Intellectual developmental disorder, X-linked, syndromic, Cabezas type, OMIM #300354). Our findings expand the mutational and clinical spectrum of CHUJANS. We discuss the molecular and clinical features in comparison to the published individuals. The fact that some variants were inherited from a mildly affected parent further illustrates the variability of the associated phenotype and outlines the importance of a thorough clinical evaluation combined with genetic analyses for accurate diagnosis and counselling.

Methylation status of hypothalamic Mkrn3 promoter across puberty.

Makorin RING finger protein 3 (MKRN3) is an important factor located on chromosome 15 in the imprinting region associated with Prader-Willi syndrome. Imprinted MKRN3 is expressed in hypothalamic regions essential for the onset of puberty and mutations in the gene have been found in patients with central precocious puberty. The pubertal process is largely controlled by epigenetic mechanisms that include, among other things, DNA methylation at CpG dinucleotides of puberty-related genes. In the present study, we investigated the methylation status of the Mkrn3 promoter in the hypothalamus of the female mouse before, during and after puberty. Initially, we mapped the 32 CpG dinucleotides in the promoter, the 5'UTR and the first 50 nucleotides of the coding region of the Mkrn3 gene. Moreover, we identified a short CpG island region (CpG islet) located within the promoter. Methylation analysis using bisulfite sequencing revealed that CpG dinucleotides were methylated regardless of developmental stage, with the lowest levels of methylation being found within the CpG islet region. In addition, the CpG islet region showed significantly lower methylation levels at the pre-pubertal stage when compared with the pubertal or post-pubertal stage. Finally, in silico analysis of transcription factor binding sites on the Mkrn3 CpG islet identified the recruitment of 29 transcriptional regulators of which 14 were transcriptional repressors. Our findings demonstrate the characterization and differential methylation of the CpG dinucleotides located in the Mkrn3 promoter that could influence the transcriptional activity in pre-pubertal compared to pubertal or post-pubertal period. Further studies are needed to clarify the possible mechanisms and effects of differential methylation of the Mkrn3 promoter.

Chromosomal Microarray Study in Prader-Willi Syndrome.

A high-resolution chromosome microarray analysis was performed on 154 consecutive individuals enrolled in the DESTINY PWS clinical trial for Prader-Willi syndrome (PWS). Of these 154 PWS individuals, 87 (56.5%) showed the typical 15q11-q13 deletion subtypes, 62 (40.3%) showed non-deletion maternal disomy 15 and five individuals (3.2%) had separate unexpected microarray findings. For example, one PWS male had Klinefelter syndrome with segmental isodisomy identified in both chromosomes 15 and X. Thirty-five (40.2%) of 87 individuals showed typical larger 15q11-q13 Type I deletion and 52 individuals (59.8%) showed typical smaller Type II deletion. Twenty-four (38.7%) of 62 PWS individuals showed microarray patterns indicating either maternal heterodisomy 15 subclass or a rare non-deletion (epimutation) imprinting center defect. Segmental isodisomy 15 was seen in 34 PWS subjects (54.8%) with 15q26.3, 15q14 and 15q26.1 bands most commonly involved and total isodisomy 15 seen in four individuals (6.5%). In summary, we report on PWS participants consecutively enrolled internationally in a single clinical trial with high-resolution chromosome microarray analysis to determine and describe an unbiased estimate of the frequencies and types of genetic defects and address potential at-risk genetic disorders in those with maternal disomy 15 subclasses in the largest PWS cohort studied to date.

Диагностические особенности синдрома Прадера–Вилли в неонатальном периоде

Objective. To demonstrate the clinical features of Prader–Willi syndrome (PWS) in the neonatal period, to assess the impact of perinatal factors on the development and severity of PWS, and to compare the data obtained with literary sources. Patients and methods. This cross-sectional open-label retrospective study was conducted between 2022 and 2023. It included 5 neonates with severe hypotonia and subsequently confirmed PWS. Anamnestic, anthropometric, age- and sex-related characteristics of children with PWS and anamnestic data of their mothers, as well as clinical manifestations of PWS were investigated. Results. Most of the children with PWS were born prematurely, with a mean birth weight of 2512.0 ± 549.5 g, height of 48.2 ± 5.1 cm, and head circumference of 32.9 ± 2.5 cm, which is below the standard values for preterm infants. The mean Apgar score was 5.8 ± 2.8/7.2 ± 1.9. Three out of five children were not appropriate for gestational age, having low values according to the INTERGROWTH-21st standards. Children were born to mothers aged 35 ± 5 years, and 3 (60%) out of 5 women had an aggravated somatic and/or obstetric and gynecological history. Evaluation of clinical manifestations of PWS revealed post-hypoxic injury of the central nervous system (CNS) (100%), respiratory disorders (100%), infectious toxicosis and intrauterine pneumonia (80%). Objective examination revealed hypotonia, hyporeflexia, reduced motor function in all patients, and 80% of children had poor sucking reflex. The most common phenotypic features were high forehead, almondshaped eyes, dolichocephaly, narrow temporal bones, thin upper lip, down-turned corners of the mouth; orbital hypertelorism, acromicria, and hypogonadism were observed less frequently. Conclusion. Early diagnosis of PWS is possible with a comprehensive differential diagnosis in children with the “floppy baby syndrome”. Special attention should be paid to children with intrauterine growth restriction, typical stigmas of dysembryogenesis, respiratory disorders, and hypoxic CNS injury. Genetic counseling and karyotyping should be performed as early as possible in all newborns with suspected PWS to prevent the development of complications. Key words: Prader–Willi syndrome, floppy baby syndrome, stigmas of dysembryogenesis, hypotonia, hyporeflexia, poor sucking reflex, feeding disorders, developmental delay, hypogonadism

Children with Prader-Willi Syndrome and COVID-19: a longitudinal study of the effect of social re-opening after the lockdown.

This study longitudinally investigated mental health indicators, body mass index (BMI), and access to school and health-care services in children with Prader-Willi syndrome (PWS) and community controls (CC) during the first wave of the COVID-19 pandemic. The parents of 71 children (34 PWS and 37 CC) aged 6-17 years completed an online questionnaire during the initial COVID-19 lockdown (T0) and the subsequent partial (T1) and full re-opening (T2). We examined access to school and health-care services, BMI, and mental health (DSM-5 Parent/Guardian Rated Cross-Cutting Syndrome Measure) across the three time-points. For BMI and DSM-5 measure, we tested within- (Friedman's ANOVA repeated measures) and between- (robustified linear mixed-models, rLMM) group differences over time. Around 30% of PWS children maintained contact with medical personnel through telemedicine. PWS children kept contact with both teachers and classmates at a lower rate than CC. At all time-points, BMI was higher in PWS than CC. During partial reopening, while children with PWS had a decrease in BMI, CC showed an increase, with a significant interaction time*group interaction. Mental symptoms significantly declined in both groups, although in CC the decrease was greater than in PWS. PWS children were at a disadvantage during the COVID-19 outbreak for lower access to school than CC. The improvement of mental health in both groups with the reopening confirms the importance of social activities outside the family. The decrease in BMI in the PWS group indicates the positive role of caregivers' monitoring on eating habits of children.

Современные особенности ведения детей с синдромом Прадера–Вилли

Prader–Willi syndrome (PWS) is a genetic disorder caused by a lack of expression of the paternally inherited chromosome 15q11.2-q13. PWS is a serious medical and social problem that requires the attention of a wide range of specialists. PWS is characterized by variability of symptoms and complex disease progression. The main clinical manifestation of the syndrome is severe hypotonia, or “floppy baby syndrome”, which is typical for the neonatal period. As a child grows, hyperphagia appears with the development of morbid obesity, as well as delay in growth, neuropsychiatric and sexual development, behavioral disorders, and cardiopulmonary complications. The diagnosis of the disease is based on clinical criteria and molecular genetic testing. The treatment of PWS is symptomatic. In addition to the use of growth hormone, examinations are carried out to evaluate the efficacy and safety of other groups of pharmacological agents for the treatment and correction of existing symptoms and complications of PWS. Timely diagnosis improves long-term outcomes and quality of life of children with this genetic pathology. The article presents current approaches to the diagnosis and management of patients with PWS. Key words: Prader–Willi syndrome, floppy baby syndrome, stigmas of dysembryogenesis, hypotonia, hyporeflexia, obesity, hyperphagia, neurodevelopmental disorders, hypogonadism

Perinatal and neonatal characteristics of Prader-Willi syndrome inJapan.

Prader-Willi syndrome (PWS) is suspected at birth if extreme hypotonia, difficulty in feeding, hypogonadism, and failure to thrive are present. Genetic diagnosis of PWS can generally be made within the first few months of life; however, a delayed diagnosis of PWS is frequently reported. Although the clinical characteristics of perinatal and neonatal patients with PWS have been reported, there are no such reports on the clinical characteristics of these patients in Japan. This retrospective, single-center study involved 177 Japanese patients with PWS and their medical data regarding the perinatal and neonatal periods were evaluated. The median maternal age at birth was 34 years; 12.7% of the mothers had a history of assisted reproductive technology (ART). Of the mothers, 13.5% reported polyhydramnios and 4.3% had oligohydramnios. Decreased fetal movement during pregnancy was reported by 76% of the mothers. A total of 60.5% of patients were born by cesarean section. Genetic subtypes included deletions (66.1%), uniparental disomy (31.0%), imprinting defects (0.6%), and other or unknown subtypes (2.3%). The median birth length was 47.5 cm and the median birthweight was 2476 g. Of the 160 patients, 14 (8.8%) were classified as small for gestational age. Most patients had hypotonia (98.8%), and 89.3% required gavage feeding at birth. Breathing problems, congenital heart disease, and undescended testis were noted in 33.1%, 7.0%, and 93.5% of patients, respectively. In our study, higher rates of ART, polyhydramnios, decreased fetal movements, cesarean section, hypotonia, feeding difficulties, and undescended testis were observed in PWS.

A questionnaire-based survey of medical conditions in adults with Prader-Willi syndrome in Japan: implications for transitional care.

Prader-Willi syndrome (PWS) is a multisystem disorder with increased mortality predominantly due to obesity-associated complications; therefore, the management of obesity has been centric to therapeutic strategies for PWS. Although a multidisciplinary team approach has been successful for this purpose during childhood, it is generally difficult to implement during adulthood because of the lack of a structured transitional care program. A more detailed understanding of the current medical conditions of adults with PWS is needed to establish this program; however, limited information is currently available on this issue in Japan. Accordingly, we performed a questionnaire-based survey on 425 patients with PWS. There were 162 adult patients aged 18 years or older with median body mass indexes (kg/m2) of 29.4 and 30.4 in males and females, respectively. The frequencies of type 2 diabetes mellitus (T2DM) and hypertension in adults with PWS were 40.4 and 19.4%, respectively. Growth hormone (GH) therapy during childhood correlated with lower rates of T2DM and hypertension during adulthood. Among adult patients, 54% were treated by pediatricians, whereas 44% were seen by internists with an endocrinologist/diabetologist being the most prevalent. Adult patients treated with GH during childhood showed a higher rate of being seen by pediatricians than those without, demonstrating that the multidisciplinary team approach, typically applied with GH therapy, may be continuously provided even after they reach adulthood. These results emphasize the importance of the seamless provision of the multidisciplinary team approach, which is of clinical importance for establishing an optimal transitional care program for PWS.

The transition from paediatric to adult care in individuals with Prader-Willi syndrome.

Prader-Willi syndrome (PWS), the most common form of syndromic obesity, is a complex neurodevelopmental genetic disorder including obesity with hyperphagia, endocrine and metabolic disorders and also psychiatric disorders. The most frequent endocrine disturbances include hypogonadism and growth hormone (GH) deficiency. Hypothyroidism and central adrenal insufficiency can also be observed but are less frequent. The transition of patients with PWS from adolescence to adult life is challenging because of multiple comorbidities and complex disability. Patients and caregivers face psychological, medical and social issues. This period of profound changes is thus prone to disruptions, the main risks being the worsening of the medical situation and loss to follow-up of the patients. Medical care may be poorly adapted to the needs of patients because of a lack of knowledge concerning the syndrome and also lack of the necessary specific skills. A multidisciplinary panel composed of several experts in PWS met in November 2021 during an endo-ERN webinar. They presented complementary aspects of PWS from the perspective of the transition including psychiatric, pediatrics and adult endocrinological and parent's and patient's point of view and shed light on the best way to approach this pivotal period.