Research Publications Archive - Foundation for Prader-Willi Research | Clinical Issues

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

Schizophrenia and bipolar disorder are common, severe, and disabling psychotic disorders, which are difficult to research. We argue that the genetically determined neurodevelopmental disorder Prader-Willi syndrome (PWS), which is associated with a high risk of affective psychotic illness, can...

High levels of caregiver burden in Prader-Willi syndrome

Objectives Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder that is characterized by hyperphagia, developmental delay, incomplete sexual development, mild-to-moderate intellectual disability, and a variety of challenging behavioral and psychiatric symptoms. The...

Hormonal, metabolic and skeletal phenotype of Schaaf-Yang syndrome: a comparison to Prader-Willi syndrome

BACKGROUND: Nonsense and frameshift mutations in the maternally imprinted, paternally expressed gene MAGEL2, located in the Prader-Willi critical region 15q11-15q13, have been reported to cause Schaaf-Yang syndrome (SYS), a genetic disorder that manifests as developmental delay/intellectual...

Aberrant White Matter Microstructure in Children and Adolescents With the Subtype of Prader-Willi Syndrome at High Risk for Psychosis

Prader-Willi Syndrome (PWS) is a complex neurogenetic disorder caused by loss of the paternal 15q11.2-q13 locus, due to deletion (DEL), maternal uniparental disomy (mUPD), or imprinting center defects. Individuals with mUPD have up to 60% risk of developing psychosis in early adulthood. Given the...

PREPL deficiency: delineation of the phenotype and development of a functional blood assay

Purpose: PREPL deficiency causes neonatal hypotonia, ptosis, neonatal feeding difficulties, childhood obesity, xerostomia, and growth hormone deficiency. Different recessive contiguous gene deletion syndromes involving PREPL and a variable combination of SLC3A1 (hypotonia-cystinuria syndrome),...

Cataplexy and Its Mimics: Clinical Recognition and Management

OPINION STATEMENT: This review describes the diagnosis and management of cataplexy: attacks of bilateral loss of muscle tone, triggered by emotions and with preserved consciousness. Although cataplexy is rare, its recognition is important as in most cases, it leads to a diagnosis of narcolepsy, a...

Muscle dysfunction caused by loss of Magel2 in a mouse model of Prader-Willi and Schaaf-Yang syndromes

Prader-Willi syndrome is characterized by severe hypotonia in infancy, with decreased lean mass and increased fat mass in childhood followed by severe hyperphagia and consequent obesity. Scoliosis and other orthopaedic manifestations of hypotonia are common in children with Prader-Willi syndrome...

Reduced Gamma-Aminobutyric Acid Is Associated With Emotional and Behavioral Problems in Prader–Willi Syndrome

Prader-Willi syndrome (PWS) is characterized by infantile hypotonia, hypogonadism, small hands and feet, distinct facial features and usually intellectual impairment. The disorder is associated with severe behavioral disturbances which include hyperphagia leading to morbid obesity, temper...

The phenotypic spectrum of Schaaf-Yang syndrome: 18 new affected individuals from 14 families

PURPOSE: Truncating mutations in the maternally imprinted, paternally expressed gene MAGEL2, which is located in the Prader-Willi critical region 15q11-13, have recently been reported to cause Schaaf-Yang syndrome, a Prader-Willi-like disease that manifests as developmental delay/intellectual...

Nutritional Phases in Prader-Willi Syndrome: Evolutionary and Clinical Interpretations

Prader-Willi syndrome (PWS) is caused by a lack of expression of paternally-expressed imprinted genes at human chromosome 15q11-13 and is characterized by a switch from infant anorexia to childhood hyperphagia. A recent multiphase staging system recognizes gradual changes between the anorexic and...

High unacylated ghrelin levels support the concept of anorexia in infants with prader-willi syndrome

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with different nutritional phases from suckling deficit with failure to thrive to early onset of obesity. Hyperghrelinemia has been described in PWS long before the development of obesity. Ghrelin is found in both...

Obesity Impairs the Action of the Neuroendocrine Ghrelin System

Ghrelin is a metabolic hormone that promotes energy conservation by regulating appetite and energy expenditure. Although some studies suggest that antagonizing ghrelin function attenuates body weight gain and glucose intolerance on a high calorie diet, there is little information about the...

USP7 Acts as a Molecular Rheostat to Promote WASH-Dependent Endosomal Protein Recycling and Is Mutated in a Human Neurodevelopmental Disorder

Endosomal protein recycling is a fundamental cellular process important for cellular homeostasis, signaling, and fate determination that is implicated in several diseases. WASH is an actin-nucleating protein essential for this process, and its activity is controlled through K63-linked...

Neural correlates of self-injurious behavior in Prader-Willi syndrome

Individuals with Prader-Willi syndrome (PWS), a genetic disorder caused by mutations to the q11-13 region on chromosome 15, commonly show severe skin-picking behaviors that can cause open wounds and sores on the body. To our knowledge, however, no studies have examined the potential neural...

Sexual dichotomy of gonadal function in Prader-Willi syndrome from early infancy through the fourth decade

STUDY QUESTION: At what age does the type of hypogonadism, namely hypothalamic or primary gonadal defect, become established in men and women with Prader-Willi syndrome (PWS)? SUMMARY ANSWER: The type of hypogonadism becomes established only in late adolescence and early adulthood. WHAT IS KNOWN...

Epigenetic mechanisms in diurnal cycles of metabolism and neurodevelopment

Abstract The circadian cycle is a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast...

Macronutrient regulation of Ghrelin and Peptide YY in Pediatric Obesity and Prader Willi Syndrome (PWS)

Abstract BACKGROUND: The roles of macronutrients and GH in the regulation of food intake in pediatric obesity and PWS are poorly understood. OBJECTIVE: We compared effects of high carbohydrate (HC) and high fat (HF) meals and GH therapy on ghrelin, insulin, PYY, and insulin sensitivity in children...

Metabolic profiling in Prader-Willi syndrome and nonsyndromic obesity: sex differences and the role of growth hormone

Abstract OBJECTIVES: To identify metabolic factors controlling appetite and insulin sensitivity in PWS and assess effects of GH treatment. METHODS: We compared amino acids, fatty acids and acylcarnitines in GH-treated and untreated PWS children and obese and lean controls to identify biomarkers...

Metabolic profiling in Prader-Willi syndrome and non-syndromic obesity: sex differences and the role of growth hormone

OBJECTIVES: To identify metabolic factors controlling appetite and insulin sensitivity in PWS and assess effects of GH treatment.

Ageing in people with Prader-Willi syndrome: mortality in the UK population cohort and morbidity in an older sample of adults

BACKGROUND: The past two decades have seen a great improvement in the care of people with Prader-Willi syndrome (PWS), particularly with regard to control of diet and behaviour management. Has this affected mortality rates or thrown up new issues regarding premature ageing or dementia? We...

Hyperphagia: Current concepts and future directions proceedings of the 2nd international conference on hyperphagia

Objective Hyperphagia is a central feature of inherited disorders (e.g., Prader–Willi Syndrome) in which obesity is a primary phenotypic component. Hyperphagia may also contribute to obesity as observed in the general population, thus raising the potential importance of common underlying mechanisms...

Longitudinal Study of Reproductive Hormones in Prader-Willi Syndrome (PWS) from Early Infancy through the Fourth Decade

Background: We previously showed in cross-sectional studies of PWS men (1) and women (2) that the etiology of hypogonadism is heterogeneous, with primary testicular failure common in PWS men and variable combinations of ovarian dysfunction and gonadotropin deficiency in women. Longitudinal studies...

Gene-Environment Interactions Controlling Energy and Glucose Homeostasis and the Developmental Origins of Obesity

Obesity and type 2 diabetes mellitus (T2DM) often occur together and affect a growing number of individuals in both the developed and developing worlds. Both are associated with a number of other serious illnesses that lead to increased rates of mortality. There is likely a polygenic mode of...

Reduced cortical complexity in children with Prader-Willi syndrome and its association with cognitive impairment and developmental delay

BACKGROUND: Prader-Willi Syndrome (PWS) is a complex neurogenetic disorder with symptoms involving not only hypothalamic, but also a global, central nervous system dysfunction. Previously, qualitative studies reported polymicrogyria in adults with PWS. However, there have been no quantitative...

Hypoglycemia in Prader-Willi syndrome

Although mouse models of Prader-Willi syndrome (PWS) suggest that hypoglycemia may be part of this syndrome, review of the literature shows little evidence that it is an issue in humans with PWS. Both adrenal and growth hormone deficiency can be seen in PWS, and both of these hormone deficiencies...

Characterization of minipuberty in infants with Prader-Willi syndrome

Background: Minipuberty describes transient activation of the hypothalamic-pituitary-gonadal axis occurring during the first few months of life. Hormone levels during minipuberty were described in only a few Prader-Willi syndrome (PWS) infant boys and have not been reported in PWS infant girls....

A double-blind randomized controlled trial of oxytocin nasal spray in Prader Willi syndrome

Individuals with Prader-Willi syndrome (PWS) have a significant reduction in the number of oxytocin-producing neurons (42%) in the hypothalamic paraventricular nucleus. A number of animal studies and observations of humans show that lesions in this region can produce PWS-like symptoms. Given the...

Experimental functional analysis of severe skin-picking behavior in Prader–Willi syndrome

Skin picking is an extremely distressing and treatment resistant behavior commonly shown by individuals with Prader–Willi syndrome (PWS). However, with the exception of a limited number of published single-case and survey studies, little is known about the environmental determinants of skin picking...

Prader-Willi syndrome, excessive daytime sleepiness, and narcoleptic symptoms: a case report

INTRODUCTION: Sleep abnormalities, including narcolepsy and cataplexy, are a common feature of Prader-Willi syndrome. Long-term treatment with the central nervous system stimulant modafinil has not been reported. In this case report we present a longitudinal perspective of sleep abnormalities in a...