Prader-Willi syndrome

Investigating the correlation between genotype and phenotype in Prader-Willi syndrome: a study of 45 cases from Brazil

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic disorder characterized by abnormalities in the 15q11-q13 region. Understanding the correlation between genotype and phenotype in PWS is crucial for improved genetic counseling and prognosis. In this study, we aimed to investigate the correlation between genotype and phenotype in 45 PWS patients who previously underwent methylation-sensitive high-resolution melting (MS-HRM) for diagnosis.

RESULTS

We employed methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) and Sanger sequencing, along with collecting phenotypic data from the patients for comparison. Among the 45 patients, 29 (64%) exhibited a deletion of 15q11-q13, while the remaining 16 (36%) had uniparental disomy. No statistically significant differences were found in the main signs and symptoms of PWS. However, three clinical features showed significant differences between the groups. Deletion patients had a higher prevalence of myopia than those with uniparental disomy, as well as obstructive sleep apnea and an unusual skill with puzzles.

CONCLUSIONS

The diagnostic tests (MS-HRM, MS-MLPA, and Sanger sequencing) yielded positive results, supporting their applicability in PWS diagnosis. The study's findings indicate a general similarity in the genotype-phenotype correlation across genetic subtypes of PWS.

Establishing a Standardized DNA Extraction Method Using NaCl from Oral Mucosa Cells for Its Application in Imprinting Diseases Such as Prader-Willi and Angelman Syndromes: A Preliminary Investigation

BACKGROUND

Diagnosing imprinting defects in neonates and young children presents challenges, often necessitating molecular analysis for a conclusive diagnosis. The isolation of genetic material from oral swabs becomes crucial, especially in settings where blood sample collection is impractical or for vulnerable populations like newborns, who possess limited blood volumes and are often too fragile for invasive procedures. Oral swab samples emerge as an excellent source of DNA, effectively overcoming obstacles associated with rare diseases.

METHODS

In our study, we specifically addressed the determination of the quality and quantity of DNA extracted from oral swab samples using NaCl procedures.

RESULTS

We compared these results with extractions performed using a commercial kit. Subsequently, the obtained material underwent MS-HRM analysis for loci associated with imprinting diseases such as Prader-Willi and Angelman syndromes.

CONCLUSIONS

Our study emphasizes the significance of oral swab samples as a reliable source for obtaining DNA for MS-HRM analysis. NaCl extraction stands out as a practical and cost-effective method for genetic studies, contributing to a molecular diagnosis that proves particularly beneficial for patients facing delays in characterization, ultimately influencing their treatment.

Precocious Puberty: Types, Pathogenesis and Updated Management

Precocious puberty (PP) means the appearance of secondary sexual characters before the age of eight years in girls and nine years in boys. Puberty is indicated in girls by the enlargement of the breasts (thelarche) in girls and in boys by the enlargement of the testes in either volume or length (testicular volume = 4 mL, testicular length = 25 mm, or both). Two types of PP are recognized - namely central PP (CPP) and peripheral PP (PPP). This paper aims to describe the clinical findings and laboratory workup of PP and to illustrate the new trends in the management of precocious sexual maturation. Gonadotropin-releasing hormone (GnRH)-independent type (PPP) refers to the development of early pubertal maturation not related to the central activation of the hypothalamic-pituitary-gonadal (HPG) axis. It is classified into genetic or acquired disorders. The most common forms of congenital or genetic causes involve McCune-Albright syndrome (MAS), familial male-limited PP, and congenital adrenal hyperplasia. The acquired causes include exogenous exposure to androgens, functioning tumors or cysts, and the pseudo-PP of profound primary hypothyroidism. On the other hand, CPP is the most common and it is a gonadotropin-dependent form. It is due to premature maturation of the HPG axis. CPP may occur as genetic alterations, such as MKRN3, DLK1, or KISS1;as a part of mutations in the epigenetic factors that regulate the HPG axis, such as Lin28b and let-7; or as a part of syndromes, central lesions such as hypothalamic hamartoma, and others. A full, detailed history and physical examination should be taken. Furthermore, several investigations should be conducted for both types of PP, including the estimation of serum gonadotropins such as luteinizing and follicle-stimulating hormones and sex steroids, in addition to a radiographic workup and thyroid function tests. Treatment depends on the type of PP: Long-acting GnRHa, either intramuscularly or implanted, is the norm of care for CPP management, while in PPP, especially in congenital adrenal hyperplasia, the goal of management is to suppress adrenal androgen secretion by glucocorticoids. In addition, anastrozole and letrozole - third-generation aromatase inhibitors - are more potent for MAS.

What endocrinologists can do to prevent cardiovascular complications in adults with Prader-Willi syndrome: Lessons from a case series

CONTEXT

Prader-Willi syndrome (PWS) is a complex rare genetic syndrome. Mortality in patients with PWS is 3% per year. In nearly half of the patients, the cause of death is of cardiopulmonary origin. Prevention, diagnosis and treatment of cardiovascular (CV) disease in PWS adults is complicated by the behavioral phenotype, reduced ability to express physical complaints, high pain threshold and obesity.

OBJECTIVE

To describe the challenges in prevention, diagnosis and treatment of CV disease in PWS adults, in order to increase awareness and improve medical care.

METHODS

Retrospective study of medical records of adults visiting the Dutch PWS reference center.

RESULTS

We describe the challenges encountered during diagnosis and treatment of four PWS adults with heart failure. All had pre-existent peripheral edema. CV risk factors in these patients were obesity (n=4), type 2 diabetes mellitus (n=2), hypertension (n=2), hypogonadism (n=3) and sleep apnea (n=2). Remarkably, all patients were younger than 40 years during their first cardiac decompensation. All patients presented with progressive shortness of breath and/or orthopnea and progressive pitting edema. In 117 controls with PWS without CV problems, 31% had leg edema.

CONCLUSION

Diagnosing CV problems in PWS adults is challenging. Peripheral edema is common in PWS adults without CV morbidity, which makes edema in general a poor marker for heart failure. However, when edema is of the pitting kind and progressive, this is a strong predictor of cardiac decompensation. We provide practical recommendations for diagnosing and treating CV problems in this vulnerable patient population.

Bone Health in Adults With Prader-Willi Syndrome: Clinical Recommendations Based on a Multicenter Cohort Study

CONTEXT

Prader-Willi syndrome (PWS) is a rare complex genetic syndrome, characterized by delayed psychomotor development, hypotonia, and hyperphagia. Hormone deficiencies such as hypogonadism, hypothyroidism, and growth hormone deficiency are common. The combination of hypotonia, low physical activity, and hypogonadism might lead to a decrease in bone mass and increase in fracture risk. Moreover, one would expect an increased risk of scoliosis due to hypotonia and low physical activity.

OBJECTIVE

To study the prevalence and risk factors for skeletal problems (reduced bone mineral density, fractures, and scoliosis) in adults with PWS.

METHODS

We retrospectively collected patient characteristics, medical history, medication, biochemical measurements, dual-energy X-ray absorptiometry scans, and spinal X-rays and reviewed the current literature.

RESULTS

We included 354 adults with PWS (median age 31 years; 43% males), of whom 51 (14%) had osteoporosis (T-score below -2.5) and 143 (54%) had osteopenia (T-score -1 to -2.5). The most prevalent modifiable risk factors for osteoporosis were hypogonadism, insufficient dairy intake, sedentary lifestyle, and corticosteroid use. Male sex was associated with osteoporosis (P = .005). Growth hormone treatment was not associated with osteoporosis. A history of vertebral fractures was present in 10 (3%) and nonvertebral fractures in 59 (17%). Scoliosis was present in 263 (80%), but no modifiable risk factors were identified.

CONCLUSION

Besides scoliosis, osteoporosis is common in adults with PWS. Based on the literature and the risk factors for osteoporosis found in our cohort, we provide practical clinical recommendations to avoid skeletal complications in these vulnerable patients.

Linking oxytocin and arginine vasopressin signaling abnormalities to social behavior impairments in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder. Global hypothalamic dysfunction is a core feature of PWS and has been implicated as a driver of many of PWS's phenotypic characteristics (e.g., hyperphagia-induced obesity, hypogonadism, short stature). Although the two neuropeptides (i.e., oxytocin [OXT] and arginine vasopressin [AVP]) most implicated in mammalian prosocial functioning are of hypothalamic origin, and social functioning is markedly impaired in PWS, there has been little consideration of how dysregulation of these neuropeptide signaling pathways may contribute to PWS's social behavior impairments. The present article addresses this gap in knowledge by providing a comprehensive review of the preclinical and clinical PWS literature-spanning endogenous neuropeptide measurement to exogenous neuropeptide administration studies-to better understand the roles of OXT and AVP signaling in this population. The preponderance of evidence indicates that OXT and AVP signaling are indeed dysregulated in PWS, and that these neuropeptide pathways may provide promising targets for therapeutic intervention in a patient population that currently lacks a pharmacological strategy for its debilitating social behavior symptoms.

Robustness of Distinctive Facial Features in Prader-Willi Syndrome: A Stereophotogrammetric Analysis and Association with Clinical and Biochemical Markers in Adult Individuals

Background: Prader-Willi syndrome (PWS) is a rare genomic imprinting disorder associated to a complex neurodevelopmental phenotype and a distinctive facial appearance. The study investigated the relationships between the quantitative facial dysmorphism in PWS and clinical and biochemical markers of the disease and its treatment. Methods: Facial images of 15 Caucasian adult individuals with PWS (8 males, 42 ± 5 years; 7 females, 37 ± 8 years; BMI 38.87 ± 8.92 kg/m2) were acquired through stereophotogrammetry. From the 3D coordinates of 38 landmarks, linear distances and angles were calculated; they were expressed as z-score values by referring to 403 healthy subjects matched for age and sex and compared by Student’s t-test with Bonferroni correction for multiple testing. Patients underwent auxological and biochemical assessment of endocrine/metabolic dysfunction and nocturnal respiratory function. An exploratory correlation analysis was performed to investigate their associations with the facial phenotype; uncorrected p-values were used. Results and Conclusions: Individuals with PWS showed decreased bifrontal diameter, facial depths, palpebral fissures, mandibular ramus length, lower vermillion height, and modified relative position of exocanthia and nasion. Since these characteristics did not show any associations with clinical and biochemical markers of PWS, they could constitute robust distinctive facial features and contribute to the diagnosis of the disorder. Individuals with PWS showed also a larger mandibular width with smaller gonial angles, thinner upper vermillion, greater inclination of the orbit relative to the Frankfurt plane, and a smaller angle of the auricles versus the facial midplane. Relationships between these facial anthropometric features and body composition, glucidic metabolism indexes, nocturnal hypoxemia episodes, or duration of GH treatment were found, suggesting their potentially useful role in the clinical monitoring and management of the disease. However, they need to be confirmed by subsequent dedicated studies.

Thyroid function in children with Prader-Willi syndrome in Southern China: a single-center retrospective case series

Background

To investigate hypothalamic-pituitary-thyroid function in children of different ages, nutritional phases, and genotypes that were diagnosed with Prader-Willi syndrome (PWS), as well as the effects of recombinant human growth hormone (rhGH) treatment on thyroid hormones in PWS patients.

Methods

One hundred and thirty PWS patients (87 boys and 43 girls) aged from newborn to 15 years (y) (median 1.25 y, mean, SD: 2.95 ± 3.45 y), were surveyed in this study. Serum thyroid hormone levels were examined at least once per3-6 months during the 2 years follow-up study. Central hypothyroidism (C-HT) was identified as low/normal thyroid-stimulating hormone (TSH) and low free thyroxine 4 (FT4).

Results

All study participants had normal neonatal TSH screening test results. The prevalence of C-HT is 36.2% (47/130). No C-HT cases were diagnosed in PWS either below 1 month (m) or above 12 y. The prevalence of C-TH would be increased with age before 3 y until reaching the peak, followed by a gradual decline over the years. The prevalence of C-HT varies significantly at different ages (Pearson's χ2 = 19.915; p < 0.01). However, there is no correlation between the C-HT prevalence and nutritional phases (Pearson's χ2 = 4.992; p = 0.288), genotypes (Pearson's χ2 = 0.292; p = 0.864), or rhGH therapy (Pearson's χ2 = 1.799; p = 0.180).

Conclusions

This study suggests the prevalence of C-TH was increased with the age before 3 y, and reached the peak in the 1 to 3 y group, then gradually declined over the years. There is no correlation between C-HT prevalence and nutritional phases, genotypes, or rhGH treatment.

Free Insulin-like Growth Factor (IGF)-I in Children with PWS

In children with Prader−Willi syndrome (PWS), the standard growth hormone (GH) dose often results in high immunoreactive IGF-I levels. These high immunoreactive IGF-I levels lead to concern because their long-term effects are unknown. As a result, clinicians have to lower the GH dose, which worsens body composition and quality of life. As clinical features do not seem to correspond to immunoreactive IGF-I values, it is questionable whether immunoreactive IGF-I is a suitable marker for GH dosing, or whether another parameter better reflects IGF-I bioavailability and bioactivity. We, therefore, investigate serum immunoreactive IGF-I, free IGF-I and IGFBP-3 levels in 70 GH-treated children with PWS. Our study showed that, although immunoreactive IGF-I levels were high (>2 SDS) in the vast majority of prepubertal and pubertal children, free IGF-I SDS levels were <0 SDS in most and <1 SDS in all. Free IGF-I correlated with the immunoreactive IGF-I, IGFBP-3 and IGF-I/IGFBP-3 ratio. We conclude that there is a major discrepancy between immunoreactive and free IGF-I levels. While in the majority of GH-treated children with PWS, immunoreactive IGF-I levels were high, free IGF-I levels were <0 SDS in most. Our data appear to be very reassuring and suggest that free IGF-I levels should also be taken into consideration when the immunoreactive IGF-I levels are >2 SDS in GH-treated children with PWS.

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

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

Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity.

AIM OF THIS REVIEW

The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org).

RESULTS

Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity.

CONCLUSION

Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

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

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

Long-term cortisol levels in hair of children and adolescents with Prader-Willi Syndrome

CONTEXT

Prader-Willi syndrome (PWS) is characterized by hypothalamic dysfunction. In children with PWS, stress-induced central adrenal insufficiency (CAI) has been described, however, daily life cortisol production may be normal. Hair cortisol concentration (HCC) is a marker of long-term systemic cortisol production. Cortisol awakening response (CAR) is the increase in cortisol level after awakening. A negative CAR might suggest hypothalamic-pituitary-adrenal (HPA)-axis reactivity problems. Little is known about HCC and CAR in children with PWS.

OBJECTIVE

To investigate long-term cortisol levels in hair and CAR in children with PWS.

DESIGN

Cross-sectional study.

PATIENTS

41 children with PWS.

SETTING

Dutch PWS Reference Center.

MAIN OUTCOME MEASURES

HCC and salivary cortisol measured by LCMS.

RESULTS

Median (IQR) HCC was 1.90 (1.02-3.30) pg/mg at a median (IQR) age of 14.5 (8.20-19.0) years, with median HCC in age-matched references being 2.63 pg/mg. Five patients (13.2%) had HCC < 2.5th percentile for age and these patients had a repeatedly negative CAR. Median HCC was significantly lower in patients with negative CAR than in patients with normal CAR (1.00 (0.22-1.59) vs. 2.25 (1.47-3.26) pg/mg, p = 0.007). One patient had both HCC < 2.5th percentile and repeatedly low morning salivary cortisol levels and negative CAR, and was diagnosed with adrenal insufficiency by overnight metyrapone test.

CONCLUSIONS

HCC were normal in the majority of children with PWS. Our data suggest that children with HCC < 2.5th percentile and (repeatedly) negative CAR might possibly have adrenal insufficiency or delayed HPA-axis responsiveness.

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

Prader-Willi syndrome (PWS) is a complex genetic syndrome characterized by hyperphagia, intellectual disability, hypotonia and hypothalamic dysfunction. Adults with PWS often have hormone deficiencies, hypogonadism being the most common. Untreated male hypogonadism can aggravate PWS-related health issues including muscle weakness, obesity, osteoporosis, and fatigue. Therefore, timely diagnosis and treatment of male hypogonadism is important. In this article, we share our experience with hypogonadism and its treatment in adult males with PWS and present a review of the literature. In order to report the prevalence and type of hypogonadism, treatment regimen and behavioral issues, we retrospectively collected data on medical interviews, physical examinations, biochemical measurements and testosterone replacement therapy (TRT) in 57 Dutch men with PWS. Fifty-six (98%) of the patients had either primary, central or combined hypogonadism. Untreated hypogonadism was associated with higher body mass index and lower hemoglobin concentrations. TRT was complicated by behavioral challenges in one third of the patients. Undertreatment was common and normal serum testosterone levels were achieved in only 30% of the patients. Based on the Dutch cohort data, review of the literature and an international expert panel discussion, we provide a practical algorithm for TRT in adult males with PWS in order to prevent undertreatment and related adverse health outcomes.

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.

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

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

A Polygenic Risk Score to Predict Future Adult Short Stature Among Children

CONTEXT

Adult height is highly heritable, yet no genetic predictor has demonstrated clinical utility compared to mid-parental height.

OBJECTIVE

To develop a polygenic risk score for adult height and evaluate its clinical utility.

DESIGN

A polygenic risk score was constructed based on meta-analysis of genomewide association studies and evaluated on the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.

SUBJECTS

Participants included 442 599 genotyped White British individuals in the UK Biobank and 941 genotyped child-parent trios of European ancestry in the ALSPAC cohort.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Standing height was measured using stadiometer; Standing height 2 SDs below the sex-specific population average was considered as short stature.

RESULTS

Combined with sex, a polygenic risk score captured 71.1% of the total variance in adult height in the UK Biobank. In the ALSPAC cohort, the polygenic risk score was able to identify children who developed adulthood short stature with an area under the receiver operating characteristic curve (AUROC) of 0.84, which is close to that of mid-parental height. Combining this polygenic risk score with mid-parental height or only one of the child's parent's height could improve the AUROC to at most 0.90. The polygenic risk score could also substitute mid-parental height in age-specific Khamis-Roche height predictors and achieve an equally strong discriminative power in identifying children with a short stature in adulthood.

CONCLUSIONS

A polygenic risk score could be considered as an alternative or adjunct to mid-parental height to improve screening for children at risk of developing short stature in adulthood in European ancestry populations.

Influence of molecular classes and growth hormone treatment on growth and dysmorphology in Prader-Willi syndrome: A multicenter study

Prader-Willi syndrome (PWS) is a complex genetic disorder with three molecular classes but clinical ascertainment is based on distinctive features. The prevalence of dysmorphic features was studied in 355 PWS participants (61% deletion, 36% maternal disomy [UPD], and 3% imprinting defects) from the National Institute of Health PWS Rare Diseases Clinical Research Network. The effect of growth hormone (GH) treatment on growth and dysmorphic features was compared. Among participants, upslanting palpebral fissures were seen in 23%; strabismus in 42%; abnormal dentition in 32%; small hands in 63% and small feet in 70%; hypopigmentation in 30%; striae in 32% and skin picking in 26%. Compared to those with UPD, participants with deletions were found to be heavier (p = 0.002), had smaller head circumference (HC) (p = 0.009), higher incidence of a flat occiput (p = 0.005); low-anterior hairline (p = 0.04); abnormal dentition (p = 0.009); abdominal striae (p = 0.045), nail abnormalities (p = 0.050), and fair-haired (p < 0.001). Participants in both genetic groups receiving GH were taller (p = 0.005), had larger HCs (p = 0.005), and longer hands (p = 0.049). This study suggested that PWS genetic subtypes and GH treatment can influence growth and dysmorphic features that may impact clinical diagnosis of PWS, such as stature, head shape and appearance of the eyes, nose, and genitalia.

Prenatal diagnosis of a 15q11.2-q14 deletion of paternal origin associated with increased nuchal translucency, mosaicism for de novo multiple unbalanced translocations involving 15q11-q14, 5qter, 15qter, 17pter and 3qter and Prader-Willi syndrome

OBJECTIVE

We present prenatal diagnosis of a 15q11.2-q14 deletion of paternal origin associated with increased nuchal translucency (NT), mosaicism for de novo multiple unbalanced translocations involving 15q11-q14, 5qter, 15qter, 17pter and 3qter, and Prader-Willi syndrome (PWS).

CASE REPORT

A 32-year-old, primigravid woman underwent amniocentesis at 18 weeks of gestation because of an increased NT thickness of 5.6 mm and abnormal maternal serum screening results in the first trimester. The pregnancy was conceived by in vitro fertilization and embryo transfer. Amniocentesis revealed a karyotype of 45,XX,der(5)t(5;15)(q35;q14),-15 [16]/45,XX,-15,der(17)t(15;17)(q14;p13)[3]/45,XX,der(15)t(15;15)(q35;q14),-15[2]. The parental karyotypes were normal. Prenatal ultrasound findings were unremarkable. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes revealed the result of arr 15q11.2q14 (22,765,628-38,651,755) × 1.0 [GRCh37 (hg19)] with a 15.886-Mb 15q11.2-q14 deletion encompassing TUBGCP5, CYFIP1, NIPA2, NIPA1, SNRPN, SNURF, SNORD116-1, IPW, UBE3A, ACTC1 and MEIS2. The pregnancy was subsequently terminated, and a malformed fetus with facial dysmorphism was delivered. The cord blood had a karyotype of 45,XX,der(5)t(5;15)(q35;q14),-15[46]/45,XX,der(3)t(3;15) (q29;q14),-15[2]/45,XX,-15,der(17)t(15;17)(q14;p13)[2]. The placenta had a karyotype of 45,XX,der(5) t(5;15)(q35;q14),-15. Polymorphic DNA marker analysis confirmed a paternal origin of the proximal 15q deletion.

CONCLUSION

Increased NT and abnormal maternal serum screening results may prenatally be associated with PWS. Chromosome 15 rearrangements in PWS include mosaicism for de novo multiple unbalanced translocations.

A pro-inflammatory phenotype is associated with behavioural traits in children with Prader-Willi syndrome

Several lines of evidence indicate that immune-inflammatory alterations are widely observed in various mental disorders. Genetic syndromes with high risk of psychiatric disorders may constitute a model for studies investigating this phenomenon. One of such genetically determined neurodevelopmental disorders is the Prader-Willi syndrome (PWS). Therefore, we aimed to profile a broad panel of immune-inflammatory markers in patients with PWS, taking into account co-morbid psychopathology. Participants were 20 children with PWS, and 20 healthy children matched for age, sex and body mass index. Behavioural symptoms and co-occurring psychopathological symptoms were assessed using the Child Behaviour Checklist (CBCL). We found significantly elevated levels of interleukin (IL)-1β and IL-13 in patients with PWS. There were significant positive correlations between the levels of IL-1β and scores of the following externalizing and internalizing CBCL domains: withdrawn/depressed, social problems, thought problems, attention problems, delinquent and aggressive behaviour in PWS children. Moreover, higher levels of IL-13 were associated with more severe psychopathology in terms of social and attention problems as well as delinquent and aggressive behaviour. Our findings imply that subclinical inflammation, observed as elevated IL-1β and IL-13 levels, appears only in PWS patients and is correlated to several psychopathological symptoms.

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.

Genetic Subtype-Phenotype Analysis of Growth Hormone Treatment on Psychiatric Behavior in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a complex multisystemic condition caused by a lack of paternal expression of imprinted genes from the 15q11.2-q13 region. Limited literature exists on the association between molecular classes, growth hormone use, and the prevalence of psychiatric phenotypes in PWS. In this study, we analyzed nine psychiatric phenotypes (depressed mood, anxiety, skin picking, nail picking, compulsive counting, compulsive ordering, plays with strings, visual hallucinations, and delusions) recognized in PWS and investigated associations with growth hormone treatment (GHT), deletions (DEL) and uniparental disomy (UPD) in a cohort of 172 individuals with PWS who met the criteria for analysis. Associations were explored using Pearson chi-square tests and univariable and multivariable logistic regression analyses to control for confounding exposures. This observational study of the largest dataset of patients with PWS to date suggested the following genetic subtype and phenotype correlations in psychiatric behaviors: (1) skin picking was more frequent in those with DEL vs. UPD; (2) anxiety was more common in those with UPD vs. DEL; and (3) an increased frequency of anxiety was noted in the UPD group treated with GHT compared to the DEL group. No other significant associations were found between the genetic subtype or GHT including for depressed mood, nail picking, compulsive counting, compulsive ordering, playing with strings, and visual hallucinations. Further studies will be required before any conclusions can be reached.

Epigenetics meets GPCR: inhibition of histone H3 methyltransferase (G9a) and histamine H3 receptor for Prader-Willi Syndrome

The role of epigenetic regulation is in large parts connected to cancer, but additionally, its therapeutic claim in neurological disorders has emerged. Inhibition of histone H3 lysine N-methyltransferase, especially G9a, has been recently shown to restore candidate genes from silenced parental chromosomes in the imprinting disorder Prader-Willi syndrome (PWS). In addition to this epigenetic approach, pitolisant as G-protein coupled histamine H3 receptor (H3R) antagonist has demonstrated promising therapeutic effects for Prader-Willi syndrome. To combine these pioneering principles of drug action, we aimed to identify compounds that combine both activities, guided by the pharmacophore blueprint for both targets. However, pitolisant as selective H3R inverse agonist with FDA and EMA-approval did not show the required inhibition at G9a. Pharmacological characterization of the prominent G9a inhibitor A-366, that is as well an inhibitor of the epigenetic reader protein Spindlin1, revealed its high affinity at H3R while showing subtype selectivity among subsets of the histaminergic and dopaminergic receptor families. This work moves prominent G9a ligands forward as pharmacological tools to prove for a potentially combined, symptomatic and causal, therapy in PWS by bridging the gap between drug development for G-protein coupled receptors and G9a as an epigenetic effector in a multi-targeting approach.

The RDoC approach for translational psychiatry: Could a genetic disorder with psychiatric symptoms help fill the matrix? the example of Prader-Willi syndrome

The Research Domain Criteria project (RDoc) proposes a new classification system based on information from several fields in order to encourage translational perspectives. Nevertheless, integrating genetic markers into this classification has remained difficult because of the lack of powerful associations between targeted genes and RDoC domains. We hypothesized that genetic diseases with psychiatric manifestations would be good models for RDoC gene investigations and would thereby extend the translational approach to involve targeted gene pathways. To explore this possibility, we reviewed the current knowledge on Prader-Willi syndrome, a genetic disorder caused by the absence of expression of some of the genes of the chromosome 15q11-13 region inherited from the father. Indeed, we found that the associations between genes of the PW locus and the modification identified in the relevant behavioral, physiological, and brain imaging studies followed the structure of the RDoC matrix and its six domains (positive valence, negative valence, social processing, cognitive systems, arousal/regulatory systems, and sensorimotor systems).

Firing activity of locus coeruleus noradrenergic neurons decreases in necdin-deficient mice, an animal model of Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by multiple respiratory, cognitive, endocrine, and behavioral symptoms, such as central apnea, intellectual disabilities, exaggerated stress responses, and temper tantrums. The locus coeruleus noradrenergic system (LC-NE) modulates a diverse range of behaviors, including arousal, learning, pain modulation, and stress-induced negative affective states, which are possibly correlated with the pathogenesis of PWS phenotypes. Therefore, we evaluated the LC-NE neuronal activity of necdin-deficient mice, an animal model of PWS.

METHODS

Heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygotes (+m/-p) animals, which were examined of LC-NE neuronal activity, developmental reflexes, and plethysmography.

RESULTS

On slice electrophysiology, LC-NE neurons of Ndntm1ky mice with necdin deficiency showed significantly decreased spontaneous activities and impaired excitability, which was mediated by enhanced A-type voltage-dependent potassium currents. Ndntm1ky mice also exhibited the neonatal phenotypes of PWS, such as hypotonia and blunt respiratory responses to hypercapnia.

CONCLUSIONS

LC-NE neuronal firing activity decreased in necdin-deficient mice, suggesting that LC, the primary source of norepinephrine in the central nervous system, is possibly involved in PWS pathogenesis.

Three years of growth hormone treatment in young adults with Prader-Willi syndrome: sustained positive effects on body composition

BACKGROUND

In children with Prader-Willi syndrome (PWS), the benefits of growth hormone treatment are well established. Several one-year studies have shown that growth hormone is also beneficial for adults with PWS, improving body composition. However, little is known about the longer-term effects. This study investigated the effects on body composition in adult patients with PWS during 3 years of growth hormone therapy in a dose of 0.33 mg/m²/day.

METHODS

Open-label, prospective study in 43 young adults with PWS with a median (IQR) age of 19.0 (17.5 to 20.7) years. Fat mass percentage SDS and lean body mass SDS were measured annually by DXA.

RESULTS

Estimated mean (95% CI) fat mass percentage SDS decreased during the three-year study from 2.1 (1.9 to 2.3) SDS at start to 1.9 (1.8 to 2.1) SDS, p = 0.012, while lean body mass SDS remained stable at - 2.1 (- 2.4 to - 1.8) SDS at start to - 1.9 (- 2.3 to - 1.6) after 3 years, p = 0.15. Fasting glucose and insulin remained similar during the three-year study, glucose being 4.6 (4.4 to 4.8) mmol/l at start and 4.6 (4.5 to 4.7) mmol/l after 3 years of growth hormone, p = 0.93 and insulin being 59.5 (42.2 to 81.5) pmol/l and 55.0 (42.4 to 69.2) pmol/l, resp., p = 0.54. There were no growth hormone-related adverse events during the study.

CONCLUSIONS

Three years of growth hormone treatment in young adults with PWS maintains the positive effects on body composition attained during childhood. Thus, adults with PWS benefit from longer-term growth hormone treatment.

TRIAL REGISTRATION

EudraCT, EudraCT number 2011-001313-14. Registered 17 October 2012.

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.

Molecular causes of sex-specific deficits in rodent models of neurodevelopmental disorders

Neurodevelopmental disorders (NDDs) such as intellectual disability and autism spectrum disorder consistently show a male bias in prevalence, but it remains unclear why males and females are affected with different frequency. While many behavioral studies of transgenic NDD models have focused only on males, the requirement by the National Institutes of Health to consider sex as a biological variable has promoted the comparison of male and female performance in wild-type and mutant animals. Here, we review examples of rodent models of NDDs in which sex-specific deficits were identified in molecular, physiological, and/or behavioral responses, showing sex differences in susceptibility to disruption of genes mutated in NDDs. Haploinsufficiency in genes involved in mechanisms such as synaptic function (GABRB3 and NRXN1), chromatin remodeling (CHD8, EMHT1, and ADNP), and intracellular signaling (CC2D1A and ERK1) lead to more severe behavioral outcomes in males. However, in the absence of behavioral deficits, females can still present with cellular and electrophysiological changes that could be due to compensatory mechanisms or differential allocation of molecular and cellular functions in the two sexes. By contrasting these findings with mouse models where females are more severely affected (MTHFR and AMBRA1), we propose a framework to approach the study of sex-specific deficits possibly leading to sex bias in NDDs.

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

Effects of recombinant human growth hormone treatment on growth, body composition, and safety in infants or toddlers with Prader-Willi syndrome: a randomized, active-controlled trial

Background

Prader-Willi syndrome (PWS) is a rare complex genetic disorder and is characterized by short stature, muscular hypotonia, abnormal body composition, psychomotor retardation, and hyperphagia. Recombinant human growth hormone (rhGH) treatment improves the symptoms in children with PWS, and early treatment results in more favorable outcomes. However, systematic studies in infants and toddlers under 2 years of age are lacking. This multicenter, randomized, active-controlled, parallel-group, open-label, Phase III study aimed to evaluate the safety of rhGH (Eutropin, LG Chem, Ltd.) and its efficacy on growth, body composition, and motor and cognitive development in infants and toddlers with PWS compared with a comparator treatment (Genotropin, Pfizer, Inc.). Eligible Korean infants or toddlers with PWS were randomly assigned to receive Eutropin or comparator (both 0.24 mg/kg/week, 6 times/week) for 1 year. Height standard deviation score (SDS), body composition, and motor and cognitive development were measured.

Results

Thirty-four subjects (less than 24 months old) were randomized into either the Eutropin (N = 17) group or the comparator (N = 17) group. After 52 weeks of rhGH treatment, height SDS and lean body mass increased significantly from baseline in both groups: the mean height SDS change (SD) was 0.75 (0.59) in the Eutropin group and 0.95 (0.66) in the comparator group, and the mean lean body mass change (SD) was 2377.79 (536.25) g in the Eutropin group and 2607.10 (641.36) g in the comparator group. In addition, percent body fat decreased significantly: the mean (SD) change from baseline was − 8.12% (9.86%) in the Eutropin group and − 7.48% (10.26%) in the comparator group. Motor and cognitive developments were also improved in both groups after the 1-year treatment. The incidence of adverse events was similar between the groups.

Conclusions

rhGH treatment for 52 weeks in infants and toddlers with PWS improved growth, body composition, and motor and cognitive development, and efficacy and safety outcomes of Eutropin were comparable to those of Genotropin. Hence, Eutropin is expected to provide safe and clinically meaningful improvements in pediatric patients with PWS.

Trial registration

The study was registered at ClinicalTrials.gov (identifier: NCT02204163) on July 30, 2014.

URL: https://clinicaltrials.gov/ct2/show/NCT02204163?term=NCT02204163&rank=1

Oral health in patients with Prader-Willi syndrome: current perspectives

Prader-Willi syndrome (PWS) is a rare complex multisystem disorder and presents several aspects related to dentistry. The purpose of this review is to present current perspectives about oral health in patients with PWS. Delay development, hyperphagia, foamy and highly viscous saliva raise the risk of caries and contribute to tooth wear. Cariogenic foods uncontrolled consumption allows to obesity and dental problems progress worsening systemic disorders. These factors can be controlled. The success in follow-ups with caries free and oral health controlled demonstrate the importance of multidisciplinary team intervention corroborated by support at home from birth to adulthood. Thereby, current perspective on the disease is that there is possibility of proper maintenance of oral health in PWS patients. Guided care interferes positively with the overall well-being and quality of life of the individual with PWS and their family. A multidisciplinary team with a focus on teaching patients and family members will help minimize eventual problems.

Validating and Applying the CSBS-ITC in Neurogenetic Syndromes

Although social communication skills are commonly delayed in children with neurogenetic syndromes (NGS), skill profiles in very young children are largely under characterized, in part due to the lack of validated assessment measures appropriate for these populations. We addressed this gap by validating and applying a popular early social communication screening measure, the Communication and Symbolic Behavior Scales Developmental Profile - Infant-Toddler Checklist (CSBS-ITC) in three previously understudied neurogenetic groups: Angelman, Prader-Willi, and Williams syndromes. Our results suggest that when used within the appropriate scope of screening and surveillance, the CSBS-ITC detects meaningful variability in skills across ages in young children with NGS and may provide useful information about both individual- and population-level social communication profiles in these populations.

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.

Gonadal function and testicular histology in males with Prader-Willi syndrome

CONTEXT

Cryptorchidism is common in Prader-Willi syndrome (PWS) males, but the testicular histology in childhood remains uncertain. The association between testicular histology and long-term gonadal function in PWS males is also unknown.

OBJECTIVES

To evaluate the relationship between testicular histology in childhood and long-term gonadal function in PWS males.

PATIENTS AND METHODS

Forty men with PWS were assessed longitudinally at our institute over the past 24 years. Clinical examinations and blood tests for LH, FSH and testosterone levels were compared with normal reference values. Tissue specimens were collected during orchiopexy and analyzed based on Nistal categories.

RESULTS

Of nine testes available for pathological assessments, two showed favourable histology (Nistal I) and seven showed unfavourable histology (Nistal II or III). Of five postpubertal males with histology available, four reached puberty spontaneously, but only one reached Tanner stage 5. In a male with favourable histology, LH and FSH were high, but testosterone was normal, though below the average of the reference range. In three males with unfavourable histology, LH was normal, but FSH was highly elevated, and testosterone was at the lower limit of normal. One patient took hCG treatment to induce puberty; this patient showed favourable histology, but LH, FSH and testosterone were not elevated in adolescence.

CONCLUSIONS

Testicular histology of PWS men in childhood varies from normal to Sertoli Cell-Only Syndrome. Regardless of the testicular histology in childhood, hypogonadism in PWS adults arises as a consequence of primary testicular dysfunction with highly elevated FSH and insufficient testosterone levels.

Hand strength and dexterity in patients with Prader-Willi syndrome: a pilot intervention study

OBJECTIVE

The study aim was to examine the hand function (hand strength and dexterity) and intervention effects of training in adults with Prader-Willi syndrome (PWS).

METHODS

Six adults with PWS (two females; mean age 26.14 years) underwent hand muscle strength and dexterity training for 3 months (2 hours per week). The following hand function tests were performed pre- and post-intervention: (1) hand grip, lateral pinch, and tip pinch hand strength tests, (2) the Box and Block test (BBT) for gross manual dexterity and (3) the Purdue Pegboard test for finger dexterity.

RESULTS

Before treatment, all subjects showed lower hand grip, lateral pinch, tip pinch strength, and poorer manual/finger dexterity relative to healthy adults. After training, hand function scores improved on many test items, but only the left hand tip pinch and the right hand BBT performance showed significant improvements.

CONCLUSIONS

All subjects showed lower hand strength and poorer manual/finger dexterity compared with healthy adults; this should be considered during physical training programs. Owing to limitations in the intervention intensity and possible subject behavioral deficits, further research is needed to clarify the effects of this intervention on hand function in PWS patients.

Functional independence of Taiwanese children with Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic disorder with obesity, developmental delay, short stature, and behavioral abnormalities. The study aimed to assess the functional independence in children with PWS. The Functional Independence Measure for Children (WeeFIM) was used to evaluate 81 children with PWS (44 boys and 37 girls) with a median age of 11 years 1 month (range 2 years 8 months to 20 years 2 months) were recruited between January 2013 and December 2016. The mean total WeeFIM score was 103.8 (maximum 126). Sixty-five patients (80%) had deletion type PWS, 16 (20.0%) had nondeletion type. The scores were 103.6 ± 18.5 for deletion and 104.8 ± 18.3 for nondeletion type (p = .405), 104.8 ± 19.3 in boys and 102.6 ± 17.3 in girls (p = .293). The mean self-care, mobility, and cognition scores were 47 (maximum 56), 33 (maximum 35), and 24 (maximum 35), respectively. All total scores and 18 subscores in the three functional domains were positively correlated with age (p < .05). Most children required assistance in problem-solving, comprehension, and expression. The WeeFIM identified the strengths and limitations of children with PWS and confirmed that support and supervision were needed in cognitive and self-care tasks.

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.

High resolution global chromosomal aberrations from spontaneous miscarriages revealed by low coverage whole genome sequencing

OBJECTIVE

Chromosome aberrations are generally considered as one of the most substantial causative factors contributing to spontaneous miscarriages. Cytogenetic analyses like G-banded karyotype and chromosomal microarray analyses are often performed to further investigate the chromosome status of a miscarried fetus.

STUDY DESIGN

Here, we describe a novel method, AnnoCNV, to detect DNA copy number variations (CNVs) using low coverage whole genome sequencing (WGS). We investigated the overall frequency of chromosomal abnormalities in 149 miscarriage specimens using AnnoCNV.

RESULTS

Among 149 fetal miscarriage samples, more than two fifths of them (42.95%, 64) carried at least one chromosomal abnormality, and a subset (40) was identified as autosomal trisomy which account for 26.84% of all samples. We have also developed a robust algorithm in AnnoCNV, which is able to differentiate specifically karyotype 69,XXY from sex chromosomal aneuploidy 45,X, and to identify 45,X/46,XX mosaicism. Lastly, across the whole genome AnnoCNV identifies CNVs, which are associated with both reported symptoms and unknown clinical conditions.

CONCLUSION

This cost-effective strategy reveals genome wide discovery of chromosome aberrations at higher resolution, which are consistent with parallel investigation conducted by SNP based assay.

The Prevalence and Treatment of Hip Dysplasia in Prader-Willi Syndrome (PWS)

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic disorder with multisystem involvement. There are a number of associated orthopaedic manifestations, the most recognized of which is scoliosis. The aim of this study was to assess the prevalence of hip dysplasia and to investigate its treatment in patients with PWS.

METHODS

Following IRB approval, all patients seen at our institution's Prader-Willi multidisciplinary clinic were retrospectively reviewed. Only patients with an ultrasound, anteroposterior (AP) spine, AP abdomen, AP hip radiograph, and/or skeletal survey were included in the study. The presence of hip dysplasia was determined based on ultrasonographic and/or radiographic measurements performed by a single fellowship trained pediatric orthopaedic surgeon. A multivariable logistic regression analysis was used to test the association between patient demographics and the prevalence of hip dysplasia. Age at diagnosis, treatment type, and outcomes were recorded for patients that underwent treatment for hip dysplasia.

RESULTS

Hip dysplasia was identified in 30% (27/90) of the patient population. Two of the 27 patients (7.4%) had normal films but had a history of resolved hip dysplasia. Prevalence was not associated with sex (P=0.7072), genetic subtype (P=0.5504), race (P=0.8537), ethnicity (P=0.2191), or duration of follow-up (P=0.4421). Eight of the 27 patients (30%) underwent hip treatment by Pavlik harness (2/8), Pavlik harness and closed reduction (1/8), closed reduction (3/8), open reduction (1/8), and unspecified hip surgery (1/8). The mean age at diagnosis was 2 months for the patients that were successfully treated for hip dysplasia (3/8) and 12 months for those who had residual dysplasia following the treatment (5/8).

CONCLUSIONS

Our study demonstrates a higher prevalence of hip dysplasia in patients with PWS than previously documented. The age at which hip dysplasia develops remains unknown; therefore, we recommend an ultrasound screening for all infants with PWS at 6 weeks of age and subsequent radiographic studies at 1, 2, 5, 10, and 15 years of age to allow for early diagnosis and intervention.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Special Care Dentistry in a Patient with Prader-Willi Syndrome through the Use of Atraumatic Restorative Treatment under General Anesthesia

Prader–Willi syndrome described in 1956 has a genetic origin, affecting both genders, varying in presence and intensity from individual to individual. A precocious diagnosis, before the manifestation of symptoms, has brought some improvement in the quality of life of the carriers in the last years. The objective of this case report was to describe the treatment realized in a 3-year-old boy who presented grade II obesity, difficulty of locomotion, hypotonia, and history of cardiopathy. A dental treatment under general anesthesia was defined, allowing an oral adequation in a single section, in which it was planned the extraction of the element 74 and atraumatic restorative treatment (ART) technique in the other teeth. The precocious intervention in this 3-year-old patient by the therapy realized with ART under general anesthesia was done with success, avoiding unnecessary extractions, preserving dental elements, and maintaining the oral cavity in adequate function.

Silent aspiration in infants with Prader-Willi syndrome identified by videofluoroscopic swallow study

Feeding intolerance in Prader-Willi syndrome (PWS) infants is well-recognized, but their swallow physiology is not well understood. Swallow dysfunction increases risks of respiratory compromise and choking, which have a high incidence in PWS. To investigate swallow pathology in PWS infants we undertook a retrospective review of videofluoroscopic swallow studies (VFSS) in infants with PWS seen at our institution. We hypothesize that VFSS will characterize swallow pathology suspected by clinical observation during a feeding evaluation and may help determine feeding safety in these infants.Retrospective review of 23 VFSS on 10 PWS infants (average age 9.7 ± 8.4 months; range 3 weeks-29 months). Logistic regression models evaluated associations between gender, genetic subtype, and growth hormone (GH) use on aspiration incidence. Polysomnographic (PSG) studies conducted on the same participant ±1 year from VFSS were examined to characterize respiratory abnormalities.There was a high rate of swallowing dysfunction (pharyngeal residue 71%, aspiration events 87%) and disordered sleep. All aspiration events were silent. There were no differences in rates of aspiration for gender, genetic subtype, or GH use.A high incidence of aspiration was identified indicating swallow dysfunction may frequently be present in infants with PWS. Comprehensive evaluation of feeding and swallowing is essential and requires a multidisciplinary approach. Providers should recognize risk factors for swallow dysfunction and consider a multidisciplinary approach to guide decision making and optimize feeding safety in PWS.

Clinical and Molecular Characterization of Prader-Willi Syndrome

OBJECTIVES

To describe the clinical presentations and molecular diagnosis to aid the clinicians in early diagnosis and appropriate management of Prader-Willi syndrome (PWS).

METHODS

Thirty-four clinically diagnosed PWS cases were enrolled after obtaining informed consent/assent. Demographic details, clinical data and anthropometry were recorded using structured proforma. The facial dysmorphology was evaluated. Appropriate genetic testing was performed to confirm the diagnosis.

RESULTS

At diagnosis, the most common clinical features included obesity (59%) and short stature (53%). Distinct dysmorphic features were observed in 67%. Neonatal hypotonia with feeding difficulty, delayed development in infancy and childhood behavioral problems were reported in 94%, 94% and 74% respectively. Food seeking behavior and hyperphagia was reported in 67%. Seizures were reported in 47%. All children had underdeveloped external genitalia. Growth hormone (GH) deficiency and impaired glucose tolerance were found in 56% and 50% respectively. Sleep related problems were seen in 67%. Skin and rectal picking were reported in 67%. FISH confirmed micro-deletion was found in 64.7% and abnormal methylation in 35%, of which uniparental disomy was confirmed in 14.7%.

CONCLUSIONS

Clinical suspicion is vital for early detection of PWS. Confirmation of the diagnosis requires complex multi-tier molecular genetic testing.

A Review of the Safety, Efficacy and Mechanisms of Delivery of Nasal Oxytocin in Children: Therapeutic Potential for Autism and Prader-Willi Syndrome, and Recommendations for Future Research

In this article, we conduct a comprehensive review of existing evidence for the safety and therapeutic potential of intranasal oxytocin in pediatric populations. Unique considerations for dosing and delivery of oxytocin to the nasal passageway in pediatric populations and methods to promote adherence are reviewed. Intranasal oxytocin has been administered to 261 children in three open-label studies and eight randomized controlled trials. To date, the only published results in pediatric populations have focused on autism spectrum disorder (ASD) and Prader-Willi syndrome (PWS). Results regarding efficacy for improving social impairment in ASD are equivocal, partially due to mixed methodological designs, dosing regimens, and outcome measures. At present, there is no randomized controlled evidence that oxytocin provides benefit to individuals with PWS. There is no clear evidence of a link between oxytocin administration and any specific adverse event. Adverse events have been assessed using medical interviews, open reports, checklists, and physiological assessments. Adverse events reports have been largely classified as mild (n = 93), with few moderate (n = 9) or severe (n = 3) events reported. There were 35 additional adverse events reported, without severity ratings. Severe events, hyperactivity and irritability, occurred at first administration in both placebo and oxytocin groups, and subsided subsequent to discontinuation. We note that adverse event monitoring is inconsistent and often lacking, and reporting of its relationship to the study drug is poor. Only one study reported adherence data to suggest high adherence. Recommendations are then provided for the delivery of nasal sprays to the nasal passageway, monitoring, and reporting of efficacy, safety, and adherence for oxytocin nasal spray trials in pediatric populations.

Rigidity in routines and the development of resistance to change in individuals with Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) commonly show debilitating resistance to change, which has been linked to cognitive deficits in task switching. Anecdotal reports suggest that exposure to flexibility in routines during development may be beneficial for limiting subsequent resistance to change in people with PWS, which is consistent with a beneficial role of such exposure on the development of task switching, highlighted in typical children. Here, we aim to investigate the development of resistance to change in individuals with PWS and hypothesise that exposure to increased rigidity in routines will be associated with increased subsequent resistance to change.

METHODS

An author-compiled informant report interview and two previously validated questionnaires were administered to the caregivers of 10 individuals with PWS (5-23 years). The interview examined rigidity in routines and resistance to change across life stages defined by easily distinguishable events (before school, during primary school, during secondary school, after school, currently), using open-ended and structured yes/no and 5-point Likert questions. Open-ended data were coded using an author-compiled system. Responses from two additional informants and data from the questionnaires were used to assess inter-informant reliability and concurrent validity of the structured questions.

RESULTS

The validity of the interview was supported by acceptable inter-rater reliability of the open-ended coding system and inter-informant reliability, internal consistency and concurrent validity of structured questions. Descriptive analyses of ratings of behaviour change showed a pattern of increasing resistance to change over the life course for the four oldest individuals, who had all been exposed to substantial rigidity in routines before and during primary school. Furthermore, only one individual - currently in primary school - was exposed to very little rigidity in routines before and during primary school, and he had showed a decrease in resistance to change after entering primary school. Open-ended data showed that more individuals currently evidencing little resistance to change had been exposed to parent or self-imposed flexibility in routines, than those currently evidencing substantial resistance to change. However, correlational analyses on rigidity and resistance to change ratings highlighted the possibility that rigidity during primary school is most relevant for developing resistance to change. Finally, open-ended data emphasised an important beneficial role of rigidity in routines for limiting the current challenging behaviour of individuals with high resistance to change.

CONCLUSION

Because task switching appears to evidence a period of high developmental sensitivity during early primary school years, we propose that this period may represent a critical time when increasing flexibility in the routines of children with PWS could limit the development of resistance to change. However, a careful balance would need to be struck, given the apparent benefit of rigid routines on current behaviour. Further work in this area is much needed.

Axial and appendicular body proportions for evaluation of limb and trunk asymmetry

Background and purpose - When children with irregular body proportions or asymmetric limbs present, it may be unclear where the pathology is located. An improved understanding of the clinical ratio between upper extremity, lower extremity, and spine length may help elucidate whether there is disproportion between the trunk and limbs, and whether there is a reduction deficit of the shorter limb rather than hypertrophy of the longer limb. Patients and methods - We used the Brush Foundation study of child growth and development, which was a prospective, longitudinal study of healthy children between the 1930s and the 1950s, and we collected serial clinical measurements for 290 children at 3,326 visits. Children ranged from 2 to 20 years of age during the study period. Linear and quadratic regression were used to construct nomographs and 95% prediction intervals for anthropometric body proportions. Results - The maximum anterior superior iliac spine height to sitting height ratio occurred at 12.4 years in females and at 14.17 years in males. Overall, the ratio of arm length to sitting height was 0.76 (SD 0.06), the ratio of arm length to anterior superior iliac spine height was 0.76 (SD 0.03), and the ratio of anterior superior iliac spine height to sitting height was 0.98 (SD 0.13). When comparing ratios between arm length, anterior superior iliac spine height, and sitting height, the smallest variance between appendicular proportions was found in the arm length to anterior superior iliac spine height ratio. Interpretation - We recommend comparisons between total arm length and anterior superior iliac spine height to distinguish limb reduction deficits from hemi-hypertrophy, with sitting height being used only if combined upper and lower extremity discrepancy is noted.

Treatment of Obesity Among Youth With Intellectual and Developmental Disabilities: An Emerging Role for Telenursing

Childhood obesity is a serious health issue, associated with medical comorbidity and psychosocial impairment that can persist into adulthood. In the United States, youth with intellectual and developmental disabilities are more likely to be obese than youth without disabilities. A large body of evidence supports the efficacy of family-based treatment of childhood obesity, including diet, physical activity, and behavior modification, but few interventions have been developed and evaluated specifically for this population. We highlight studies on treatment of obesity among youth with intellectual and developmental disabilities, including both residential/educational settings as well as outpatient/hospital settings. All interventions were delivered in-person, and further development of promising approaches and delivery via telenursing may increase access by youth and families. Nursing scientists can assume an important role in overcoming barriers to care for this vulnerable and underserved population.