Differential DNA methylation in iPSC-derived dopaminergic neurons: a step forward on the role of SNORD116 microdeletion in the pathophysiology of addictive behavior in Prader-Willi syndrome

INTRODUCTION

A microdeletion including the SNORD116 gene (SNORD116 MD) has been shown to drive the Prader-Willi syndrome (PWS) features. PWS is a neurodevelopmental disorder clinically characterized by endocrine impairment, intellectual disability and psychiatric symptoms such as a lack of emotional regulation, impulsivity, and intense temper tantrums with outbursts. In addition, this syndrome is associated with a nutritional trajectory characterized by addiction-like behavior around food in adulthood. PWS is related to the genetic loss of expression of a minimal region that plays a potential role in epigenetic regulation. Nevertheless, the role of the SNORD116 MD in DNA methylation, as well as the impact of the oxytocin (OXT) on it, have never been investigated in human neurons.

METHODS

We studied the methylation marks in induced pluripotent stem-derived dopaminergic neurons carrying a SNORD116 MD in comparison with those from an age-matched adult healthy control. We also performed identical neuron differentiation in the presence of OXT. We performed a genome-wide DNA methylation analysis from the iPSC-derived dopaminergic neurons by reduced-representation bisulfite sequencing. In addition, we performed RNA sequencing analysis in these iPSC-derived dopaminergic neurons differentiated with or without OXT.

RESULTS

The analysis revealed that 153,826 cytosines were differentially methylated between SNORD116 MD neurons and control neurons. Among the differentially methylated genes, we determined a list of genes also differentially expressed. Enrichment analysis of this list encompassed the dopaminergic system with COMT and SLC6A3. COMT displayed hypermethylation and under-expression in SNORD116 MD, and SLC6A3 displayed hypomethylation and over-expression in SNORD116 MD. RT-qPCR confirmed significant over-expression of SLC6A3 in SNORD116 MD neurons. Moreover, the expression of this gene was significantly decreased in the case of OXT adjunction during the differentiation.

CONCLUSION

SNORD116 MD dopaminergic neurons displayed differential methylation and expression in the COMT and SLC6A3 genes, which are related to dopaminergic clearance.

Imprinting disorders

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

Food socialization of children with Prader-Willi syndrome: an interdisciplinary problematization

Eating "disorders" of people with Prader-Willi syndrome are frequently reported in the biomedical literature. The eating behaviors are presented as a syndrome-specific trajectory over the course of a lifetime. Infants initially show anorexic behavior, which then develops into hyperphagia that lasts from childhood to adulthood and is characterized by strong cravings for food and relentless thinking about it. However, the sociocultural determinants of these food practices are not fully understood. In the first section of this article, we carry out a literature review of medical articles published on disordered eating in children with PWS. The second section draws on a social science perspective and offers an interdisciplinary problematization using the concept of food socialization. To conclude, the third section explores the challenges facing research and new questions that emerge from the alternative problematization that is the PWS Food Social Norms Internalization (FSNI) theory.

Amygdala hyperactivation relates to eating behaviour: a potential indicator of food addiction in Prader-Willi syndrome

Prader-Willi syndrome is a rare neurodevelopmental genetic disorder characterized by various endocrine, cognitive and behavioural problems. The symptoms include an obsession for food and reduced satiety, which leads to hyperphagia and morbid obesity. Neuropsychological studies have reported that Prader-Willi patients display altered social interactions with a specific weakness in interpreting social information and responding to them, a symptom close to that observed in autism spectrum disorders. In the present case-control study, we hypothesized that brain regions associated with compulsive eating behaviour would be abnormally activated by food-related odours in Prader-Willi syndrome, as these can stimulate the appetite and induce hunger-related behaviour. We conducted a brain imaging study using the olfactory modality because odours have a high-hedonic valence and can cause stronger emotional reactions than other modalities. Further, the olfactory system is also intimately associated with the endocrine regulation of energy balance and is the most appropriate modality for studies of Prader-Willi syndrome. A total of 16 Prader-Willi participants were recruited for this study, which is a significant achievement given the low incidence rate of this rare disease. The second group of 11 control age-matched subjects also participated in the brain imaging study. In the MRI scanner, using an MRI-compatible olfactometer during 56 block sessions, we randomly presented two odours (tulip and caramel), which have different hedonic valence and a different capacity to arouse hunger-related behaviour. Our results demonstrate that Prader-Willi participants have abnormal activity in the brain reward system that regulates eating behaviour. Indeed, we found that these patients had right amygdala activity up to five times higher in response to a food odour (caramel) compared with the tulip odour. In contrast, age-matched control participants had similar activity levels in response to both odours. The amygdala activity levels were found to be associated with the severity of the hyperphagia in Prader-Willi patients. Our results provide evidence for functional alteration of the right amygdala in Prader-Willi syndrome, which is part of the brain network involved in food addiction modulated by the ghrelin and oxytocin systems, which may drive the hyperphagia. Our study provides important new insights into the functioning of emotion-related brain circuits and pathology, and it is one of the few to explore the dysfunction of the neural circuits involved in emotion and addiction in Prader-Willi syndrome. It suggests new directions for the exploration and remediation of addictive behaviours.

Treatment burden, adherence, and quality of life in children with daily GH treatment in France

OBJECTIVE

The objective of this study was to describe in a real-life setting the treatment burden and adherence and quality of life (QOL) of children treated with daily injections of growth hormone and their relationship with treatment duration.

DESIGN

This non-interventional, multicenter, cross-sectional French study involved children aged 3-17 years treated with daily growth hormone injections.

METHODS

Based on a recent validated dyad questionnaire, the mean overall life interference total score (100 = most interference) was described, with treatment adherence and QOL, using the Quality of Life of Short Stature Youth questionnaire (100 = best). All analyses were performed according to treatment duration prior to inclusion.

RESULTS

Among the 275/277 analyzed children, 166 (60.4%) had only growth hormone deficiency (GHD). In the GHD group, the mean age was 11.7 ± 3.2 years; median treatment duration was 3.3 years (interquartile range 1.8-6.4). The mean overall life interference total score was 27.7 ± 20.7 (95% CI (24.2; 31.2)), with non-significant correlation with treatment duration (P = 0.1925). Treatment adherence was good (95.0% of children reported receiving >80% of planned injections over the last month); it slightly decreased with treatment duration (P = 0.0364). Children's overall QOL was good (81.5 ± 16.6 and 77.6 ± 18.7 according to children and parents, respectively), but subscores of the coping and treatment impact domains were <50. Similar results were observed in all patients independently of the condition requiring treatment.

CONCLUSIONS

This real-life French cohort confirms the treatment burden of daily growth hormone injections, as previously reported in an interventional study.

Obesity, Overweight, and Pituitary Stalk Interruption Syndrome in Children and Young Adults

CONTEXT

Pituitary stalk interruption syndrome (PSIS) is rare in the pediatric population. It combines ectopic posterior pituitary stalk interruption and anterior pituitary hypoplasia with hormonal deficiencies. The phenotype is highly heterogeneous and obesity/overweight seems to be underreported in the literature.

OBJECTIVE

To identify patients with PSIS and obesity or overweight, describe their phenotype, and compare them with patients with PSIS without overweight/obesity.

METHODS

Sixty-nine children and young adults with PSIS in a Toulouse cohort from 1984 to 2019 were studied. We identified 25 obese or overweight patients (OB-OW group), and 44 were nonobese/overweight (NO group). Then the groups were compared.

RESULTS

All cases were sporadic. The sex ratio was 1.6. The main reason for consultation in both groups was growth retardation (61% in OB-OW group, 77% in NO group). History of neonatal hypoglycemia was more common in the OB-OW than in the NO group (57% vs 14%, P = .0008), along with extrapituitary malformations (64% vs 20%, P < 0001). The incidence of caesarean section was higher in the OB-OW group (52%) than in the NO group (23%), although not significant (P = .07).

CONCLUSION

Patients with PSIS who are obese/overweight display interesting phenotypic differences that suggest hypothalamic defects. Studies are needed that include additional information on hormonal levels, particularly regarding oxytocin and ghrelin.

The transition from pediatric 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 individuals with PWS from adolescence to adult life is challenging because of multiple comorbidities and complex disabilities. Individuals and caregivers face psychological, medical and social issues. This period of profound changes is thus prone to disruptions, and the main risks being the worsening of the medical situation and loss to follow-up of the individuals. Medical care may be poorly adapted to the needs of individuals 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 European Reference Network on Rare Endocrine Conditions (Endo-ERN) webinar. They presented complementary aspects of PWS from the perspective of the transition including psychiatric, pediatric and adult endocrinological and parent's and patient's points of view and shed light on the best way to approach this pivotal period.

First step towards a consensus strategy for multi-locus diagnostic testing of imprinting disorders

Background

Imprinting disorders, which affect growth, development, metabolism and neoplasia risk, are caused by genetic or epigenetic changes to genes that are expressed from only one parental allele. Disease may result from changes in coding sequences, copy number changes, uniparental disomy or imprinting defects. Some imprinting disorders are clinically heterogeneous, some are associated with more than one imprinted locus, and some patients have alterations affecting multiple loci. Most imprinting disorders are diagnosed by stepwise analysis of gene dosage and methylation of single loci, but some laboratories assay a panel of loci associated with different imprinting disorders. We looked into the experience of several laboratories using single-locus and/or multi-locus diagnostic testing to explore how different testing strategies affect diagnostic outcomes and whether multi-locus testing has the potential to increase the diagnostic efficiency or reveal unforeseen diagnoses.

Results

We collected data from 11 laboratories in seven countries, involving 16,364 individuals and eight imprinting disorders. Among the 4721 individuals tested for the growth restriction disorder Silver–Russell syndrome, 731 had changes on chromosomes 7 and 11 classically associated with the disorder, but 115 had unexpected diagnoses that involved atypical molecular changes, imprinted loci on chromosomes other than 7 or 11 or multi-locus imprinting disorder. In a similar way, the molecular changes detected in Beckwith–Wiedemann syndrome and other imprinting disorders depended on the testing strategies employed by the different laboratories.

Conclusions

Based on our findings, we discuss how multi-locus testing might optimise diagnosis for patients with classical and less familiar clinical imprinting disorders. Additionally, our compiled data reflect the daily life experiences of diagnostic laboratories, with a lower diagnostic yield than in clinically well-characterised cohorts, and illustrate the need for systematising clinical and molecular data.

Turner syndrome: French National Diagnosis and Care Protocol (NDCP; National Diagnosis and Care Protocol)

Turner syndrome (TS; ORPHA 881) is a rare condition in which all or part of one X chromosome is absent from some or all cells. It affects approximately one in every 1/2500 liveborn girls. The most frequently observed karyotypes are 45,X (40–50%) and the 45,X/46,XX mosaic karyotype (15–25%). Karyotypes with an X isochromosome (45,X/46,isoXq or 45,X/46,isoXp), a Y chromosome, X ring chromosome or deletions of the X chromosome are less frequent. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins) is to provide health professionals with information about the optimal management and care for patients, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Center for Rare Growth and Developmental Endocrine disorders, is available from the French Health Authority website. Turner Syndrome is associated with several phenotypic conditions and a higher risk of comorbidity. The most frequently reported features are growth retardation with short adult stature and gonadal dysgenesis. TS may be associated with various congenital (heart and kidney) or acquired diseases (autoimmune thyroid disease, celiac disease, hearing loss, overweight/obesity, glucose intolerance/type 2 diabetes, dyslipidemia, cardiovascular complications and liver dysfunction). Most of the clinical traits of TS are due to the haploinsufficiency of various genes on the X chromosome, particularly those in the pseudoautosomal regions (PAR 1 and PAR 2), which normally escape the physiological process of X inactivation, although other regions may also be implicated. The management of patients with TS requires collaboration between several healthcare providers. The attending physician, in collaboration with the national care network, will ensure that the patient receives optimal care through regular follow-up and screening. The various elements of this PNDS are designed to provide such support.

Approach to the Patient With Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a rare, multisystemic, genetic disorder involving the hypothalamus. It is caused by loss of expression of paternally inherited genes in chromosome 15 q11-13 region. The estimated incidence is around 1 in 20.000 births. PWS is characterized by a complex lifelong trajectory involving neurodevelopmental, nutritional, endocrine, metabolic, and behavioral changes. The major symptoms are hypotonia, short stature, hypogonadism, and eating disorders ranging from anorexia in infancy to hyperphagia, a deficit of satiety, and a high risk of severe obesity. The patients display intellectual disability comprising cognitive deficit, delayed motor and language development, learning deficits, impaired social skills, and emotional regulation. Behavioral features including temper outbursts, anxiety, obsessive-compulsive symptoms and rigidity are common and become more apparent with increasing age. Almost all have hypogonadism and growth hormone deficiency. Central adrenal insufficiency is rare whereas central hypothyroidism occurs in up to 30% of children with PWS. The prevalence of obesity increases with age from almost none in early childhood to more than 90% in adulthood. Up to 25% of adults with obesity have type 2 diabetes. Obesity and its complications are the major causes of comorbidity and mortality in PWS. As there is no specific treatment, care consists of comprehensive management of feeding disorders, a restricted, controlled diet, regular exercise, hormone substitution, and screening and treatment of comorbidities. Here we present the course of PWS from birth to adulthood in 2 patients and discuss their symptoms in relation to the literature.

Hypothalamic syndrome

Hypothalamic syndrome (HS) is a rare disorder caused by disease-related and/or treatment-related injury to the hypothalamus, most commonly associated with rare, non-cancerous parasellar masses, such as craniopharyngiomas, germ cell tumours, gliomas, cysts of Rathke's pouch and Langerhans cell histiocytosis, as well as with genetic neurodevelopmental syndromes, such as Prader-Willi syndrome and septo-optic dysplasia. HS is characterized by intractable weight gain associated with severe morbid obesity, multiple endocrine abnormalities and memory impairment, attention deficit and reduced impulse control as well as increased risk of cardiovascular and metabolic disorders. Currently, there is no cure for this condition but treatments for general obesity are often used in patients with HS, including surgery, medication and counselling. However, these are mostly ineffective and no medications that are specifically approved for the treatment of HS are available. Specific challenges in HS are because the syndrome represents an adverse effect of different diseases, and that diagnostic criteria, aetiology, pathogenesis and management of HS are not completely defined.

Relationship between adherence to growth hormone therapy and growth

Adherence to growth hormone (GH) therapy in children is variable and remains a problem which can significantly affect the response to GH treatment and future health and also have economic consequences. The response to GH treatment is not predictable at the start of treatment and depends on several factors, the main one being the diagnosis. Knowing the factors associated with poor adherence before treatment initiation can improve the response to treatment. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Low bone mass in Noonan syndrome children correlates with decreased muscle mass and low IGF-1 levels

Although musculoskeletal abnormalities have long been described in patients with Noonan syndrome (NS), only a few studies have investigated the bone status of these patients. The aim of this retrospective observational study was to describe the bone health of children with NS. Thirty-five patients with a genetically confirmed diagnosis of NS were enrolled. We analyzed the axial skeleton (lumbar spine) using dual energy X-ray absorptiometry and the appendicular skeleton (hand) with the BoneXpert system. Bone metabolism markers, including mineral homeostasis parameters, serum 25-hydroxy vitamin D (25-OHD) levels and markers of bone formation and resorption were also reported. Compared to the general population, axial and appendicular bone mass was significantly decreased in children with NS (p < 0.0001). Serum 25-OHD levels were low in about half of the patients and were negatively correlated with age (r = -0.52; p < 0.0001). Patients with NS exhibited reduced bone formation marker levels and increased bone resorption marker levels (p < 0.0001). No gender difference or genotype-phenotype correlations were found for the different bone parameters. Muscle mass and, to a lesser extent, serum insulin-like growth factor 1 (IGF-1) levels were independent predictors of whole-body bone mineral content (p < 0.0001 for both parameters; adjusted R² = 0.97). In conclusion, bone mass is reduced in children with NS and correlates with decreased muscle mass and low serum IGF-1 levels. These data justify addressing all potential threats to bone health including sufficient calcium and vitamin D intake, regular physical exercise, and hormone replacement therapy.

Diabetes Mellitus in Prader-Willi Syndrome: Natural History during the Transition from Childhood to Adulthood in a Cohort of 39 Patients

Type 2 diabetes mellitus (T2DM) affects 20% of patients with Prader-Willi syndrome (PWS), with many cases diagnosed during the transition period. Our aim was to describe the natural history of T2DM in patients with PWS before the age of 25 years and to develop screening and preventive strategies. Thirty-nine patients followed in the French PWS Reference Center were included (median age 25.6 years [23.7; 31.7]). Twenty-one had been treated with growth hormone (GH), fifteen had not, and three had an unknown status. The median age at T2DM diagnosis was 16.8 years (11–24) and the median BMI was 39 kg/m² [34.6; 45], with 34/35 patients living with obesity. The patients displayed frequent psychiatric (48.3% hospitalization,) and metabolic (56.4% hypertriglyceridemia,) comorbidities and a parental history of T2DM (35.7%) or overweight (53.6%) compared to the PWS general population. There was no difference in BMI and metabolic complications between the GH-treated and non-GH-treated groups at T2DM diagnosis. Patients with PWS who develop early T2DM have severe obesity, a high frequency of psychiatric and metabolic disorders, and a family history of T2DM and overweight. These results underline the need for early identification of patients at risk, prevention of obesity, and repeated blood glucose monitoring during the transition period.

Reasons for Discontinuation of dupilumab in Adult Atopic Dermatitis in Clinical Practice

Dupilumab, an anti-IL-4ɑ monoclonal antibody, has shown a positive benefit-risk ratio when treating moderate to severe atopic dermatitis (AD) in clinical studies (1). High persistence on dupilumab has recently been reported in clinical-practice setting with 77% of patients remaining in treatment for 12 months in a retrospective study including 1,963 patients with AD but reasons for discontinuation were not investigated (2).

Hyponatremia in Children and Adults with Prader-Willi Syndrome: A Survey Involving Seven Countries

In Prader–Willi syndrome (PWS), conditions that are associated with hyponatremia are common, such as excessive fluid intake (EFI), desmopressin use and syndrome of inappropriate antidiuretic hormone (SIADH) caused by psychotropic medication. However, the prevalence of hyponatremia in PWS has rarely been reported. Our aim was to describe the prevalence and severity of hyponatremia in PWS. In October 2020, we performed a retrospective study based on the medical records of a large cohort of children and adults with PWS from seven countries. Among 1326 patients (68% adults), 34 (2.6%) had at least one episode of mild or moderate hyponatremia (125 ≤ Na < 135 mmol/L). The causes of non-severe hyponatremia were often multi-factorial, including psychotropic medication in 32%, EFI in 24% and hyperglycemia in 12%. No obvious cause was found in 29%. Seven (0.5%) adults experienced severe hyponatremia (Na < 125 mmol/L). Among these, five recovered completely, but two died. The causes of severe hyponatremia were desmopressin treatment for nocturnal enuresis (n = 2), EFI (n = 2), adrenal insufficiency (n = 1), diuretic treatment (n = 1) and unknown (n = 1). In conclusion, severe hyponatremia was very rare but potentially fatal in PWS. Desmopressin treatment for nocturnal enuresis should be avoided. Enquiring about EFI and monitoring serum sodium should be included in the routine follow-ups of patients with PWS.

Paradoxical low severity of COVID-19 in Prader-Willi syndrome: data from a French survey on 647 patients

BACKGROUND

Patients with Prader-Willi syndrome (PWS) often have comorbidities, especially obesity, that may constitute a risk factor for severe forms of COVID-19. We aimed to assess prevalence and medical course of SARS-CoV-2 infection in children and adults with PWS. From November 2020 to January 2021, we performed a detailed medical survey on 342 adults and 305 children with PWS followed in the French reference center.

RESULTS

We obtained responses from 288 adults (84%) and 239 children (78%). From March 2020 to January 2021, 38 adults (13.2%) and 13 children (5.4%) with PWS had SARS-CoV-2 infection. Mean age of adults was 34.1 ± 11.9 years and mean body mass index was 40.6 ± 12.7 kg/m2; 82% had obesity and 37% had diabetes. Only 3 children (23%) had obesity and none had diabetes. Similar to the general population, the most frequent symptoms of COVID-19 were asthenia, fever, cough, headache and shortness of breath. All patients had a favorable outcome.

CONCLUSION

PWS itself is not a risk factor for severe COVID-19 in children and adults. On the contrary, evolution of SARS-CoV-2 infection in adults with PWS seems more favorable than expected, given their comorbidities.

Prader-Willi syndrome: Hormone therapies

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder linked to the lack of expression of specific maternally imprinted genes located in the chromosomal region 15q11-q13. Impaired hypothalamic development and function explain most of the phenotype that is characterized by a specific trajectory from anorexia at birth to excessive weight gain at later ages, which is accompanied by hyperphagia and early severe obesity, as well as by other hormonal deficiencies, behavioral deficits, and dysautonomia. In almost all patients, their endocrine dysfunction involves growth hormone deficiency and hypogonadism, which originate from a combination of both peripheral and hypothalamic origin, central hypothyroidism in 40%, precocious adrenarche in 30% of the cases, and in rare cases, also adrenocorticotropin deficiency and precocious puberty. In addition, the oxytocin (OXT) and ghrelin systems are impaired in most patients and involved in a poor suckling response at birth, and hyperphagia with food addiction, poor social skills, and emotional dysregulation. Current hormonal replacement treatments are the same as used in classical hormonal deficiencies, and recombinant human GH treatment is registered since 2000 and has dramatically changed the phenotype of these children. OXT and OXT analogue treatments are currently investigated as well as new molecules targeting the ghrelin system. The severe condition of PWS can be seen as a model to improve the fine description and treatments of hypothalamic dysfunction.

Childhood epidermal necrolysis and erythema multiforme major: a multicentre French cohort study of 62 patients

INTRODUCTION

The distinction between epidermal necrolysis [EN; including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and overlap syndrome] and erythema multiforme major (EMM) in children is confusing. We aimed to better describe and compare these entities.

MATERIALS AND METHODS

This French retrospective multicentre study included children ≤18 years old referred for EN or EMM between 1 January 2008 and 1 March 2019. According to pictures, children were reclassified into TEN/overlap, SJS or EMM/unclassified (SJS/EMM) groups and compared for epidemiological and clinical data, triggers, histology and follow-up.

RESULTS

We included 62 children [43 boys, median age 10 years (range 3-18)]: 16 with TEN/overlap, 11 SJS and 35 EMM. The main aetiologies were drugs in EN and infections (especially Mycoplasma pneumoniae) in EMM (P < 0.001), but 35% of cases remained idiopathic (TEN/overlap, 47%; SJS, 24%; EMM, 34%). The typical target lesions predominated in EMM (P < 0.001), the trunk was more often affected in EN (P < 0.001), and the body surface area involved was more extensive in EN (P < 0.001). Mucosal involvement did not differ between the groups. Two patients with idiopathic TEN died. Histology of EMM and EN showed similar features. The recurrence rate was 42% with EMM, 7% with TEN/overlap and 0 with SJS (P < 0.001). Sequelae occurred in 75% of EN but involved 55% of EMM.

CONCLUSION

Clinical features of EN and EMM appeared well demarcated, with few overlapping cases. Idiopathic forms were frequent, especially for EN, meaning that a wide and thorough infectious screening, repeated if needed, is indicated for all paediatric cases of EN/EMM without any trigger drug. We propose a comprehensive panel of investigations which could be a standard work-up in such situation. Sequelae affected both EN and EMM.

Impact of baricitinib in combination with topical steroids on atopic dermatitis symptoms, quality of life and functioning in adult patients with moderate-to-severe atopic dermatitis from the BREEZE-AD7 Phase 3 randomized trial

Background

Baricitinib is an oral, selective, reversible Janus kinase 1/2 inhibitor approved in the European Union and Japan and under investigation in the United States for treatment of atopic dermatitis (AD).

Objectives

To evaluate the impact of baricitinib plus background topical corticosteroids (TCS) on health‐related quality of life (HRQoL), how AD symptoms impact work productivity and life functioning, and treatment benefit using patient‐reported outcome (PRO) assessments in patients with moderate‐to‐severe AD previously experiencing inadequate response to TCS.

Methods

Adult patients with AD in BREEZE‐AD7, a Phase 3, multicentre, double‐blind trial, were randomised 1 : 1 : 1 to daily oral placebo (control) or baricitinib 4‐ or 2‐mg plus TCS. PROs reported Week 1 through Week 16: Dermatology Life Quality Index (DLQI), Work Productivity and Activity Impairment‐AD (WPAI‐AD); Patient‐Reported Outcomes Measurement Information System (PROMIS) Itch and Sleep measures, and Patient Benefit Index (PBI). Data were analysed using logistic regression (categorical) and mixed model repeated measures (continuous). PBI scores were analysed using analysis of variance.

Results

A total of 329 patients were randomised. Treatment with baricitinib 4‐mg (N = 111) or 2 mg (N = 109) plus TCS led to rapid, statistically significant improvements [vs. TCS plus placebo (N = 109)] in DLQI ≥4‐point improvement starting at Week 2 (4‐mg plus TCS, P ≤ 0.001; 2‐mg plus TCS P ≤ 0.05), change from baseline in WPAI‐AD presenteeism at Week 1 (4‐mg plus TCS, P ≤ 0.01; 2‐mg plus TCS P ≤ 0.05) and PROMIS itch interference at Week 2 (4‐mg plus TCS P ≤ 0.01). Improvements were sustained through Week 16 for baricitinib 4‐mg. Statistically significant improvements were observed at Week 16 for PBI global score (4‐mg plus TCS, P ≤ 0.001; 2‐mg plus TCS P ≤ 0.05).

Conclusions

Baricitinib plus TCS vs. placebo plus TCS showed significant improvements in treatment benefit at Week 16 and rapid significant improvements in HRQoL and impact of AD symptoms on work productivity and functioning through 16 weeks.

Effects of the COVID-19 pandemic and lockdown on the mental and physical health of adults with Prader-Willi syndrome

Background

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder with hypothalamic dysfunction leading to obesity and behavioral disabilities, including eating disorders (EDs). We evaluated the effects of the COVID-19 infection and lockdown on mental and physical health in PWS. At the end of April, 85 adults with PWS completed a self-administered questionnaire, including lockdown conditions, physical activity (PA), ED, and medical and behavioral outcomes. Body weight was measured at home and self-reported.

Results

Patients (52.9% women, 44.8% disomic) were assessed, with a mean age of 28.05 ± 8.73 years and body mass index (BMI) of 36.76 ± 10.74 kg/m². Seventy percent lived in the Paris region (France) and were confined with their parents. The mean weight change was 0.96 ± 3.28 kg. We compared patients showing weight loss (n = 39, − 3.30 ± 2.93 kg) to patients showing weight gain (n = 22, + 2.35 ± 1.54 kg): the BMI was lower (34.60 ± 9.18 versus 40.45 ± 9.45 kg/m², p = 0.02), PA increased (25.6% versus 4.5%, p = 0.04), and EDs improved (51.3% versus 13.6%, p = 0.005). Behavioral disorders increased for 12.9% of the cohort. Three individuals (3.5%) were diagnosed with non-severe COVID-19.

Conclusion

Lockdown during the COVID-19 pandemic was associated with positive effects for most French adults with PWS, with weight loss probably associated with a more favourable environment during this period. We observed no severe forms of COVID-19.

SHP2 drives inflammation-triggered insulin resistance by reshaping tissue macrophage populations

Insulin resistance is a key event in type 2 diabetes onset and a major comorbidity of obesity. It results from a combination of fat excess-triggered defects, including lipotoxicity and metaflammation, but the causal mechanisms remain difficult to identify. Here, we report that hyperactivation of the tyrosine phosphatase SHP2 found in Noonan syndrome (NS) led to an unsuspected insulin resistance profile uncoupled from altered lipid management (for example, obesity or ectopic lipid deposits) in both patients and mice. Functional exploration of an NS mouse model revealed this insulin resistance phenotype correlated with constitutive inflammation of tissues involved in the regulation of glucose metabolism. Bone marrow transplantation and macrophage depletion improved glucose homeostasis and decreased metaflammation in the mice, highlighting a key role of macrophages. In-depth analysis of bone marrow-derived macrophages in vitro and liver macrophages showed that hyperactive SHP2 promoted a proinflammatory phenotype, modified resident macrophage homeostasis, and triggered monocyte infiltration. Consistent with a role of SHP2 in promoting inflammation-driven insulin resistance, pharmaceutical SHP2 inhibition in obese diabetic mice improved insulin sensitivity even better than conventional antidiabetic molecules by specifically reducing metaflammation and alleviating macrophage activation. Together, these results reveal that SHP2 hyperactivation leads to inflammation-triggered metabolic impairments and highlight the therapeutical potential of SHP2 inhibition to ameliorate insulin resistance.

Growth Restriction and Genomic Imprinting-Overlapping Phenotypes Support the Concept of an Imprinting Network

Intrauterine and postnatal growth disturbances are major clinical features of imprinting disorders, a molecularly defined group of congenital syndromes caused by molecular alterations affecting parentally imprinted genes. These genes are expressed monoallelically and in a parent-of-origin manner, and they have an impact on human growth and development. In fact, several genes with an exclusive expression from the paternal allele have been shown to promote foetal growth, whereas maternally expressed genes suppress it. The evolution of this correlation might be explained by the different interests of the maternal and paternal genomes, aiming for the conservation of maternal resources for multiple offspring versus extracting maximal maternal resources. Since not all imprinted genes in higher mammals show the same imprinting pattern in different species, the findings from animal models are not always transferable to human. Therefore, human imprinting disorders might serve as models to understand the complex regulation and interaction of imprinted loci. This knowledge is a prerequisite for the development of precise diagnostic tools and therapeutic strategies for patients affected by imprinting disorders. In this review we will specifically overview the current knowledge on imprinting disorders associated with growth retardation, and its increasing relevance in a personalised medicine direction and the need for a multidisciplinary therapeutic approach.

Endocrine disorders in Prader-Willi syndrome: a model to understand and treat hypothalamic dysfunction

Prader-Willi syndrome is a rare genetic neurodevelopmental disorder resulting from the loss of expression of maternally imprinted genes located in the paternal chromosomal region, 15q11-13. Impaired hypothalamic development and function is the cause of most of the phenotypes comprising the developmental trajectory of Prader-Willi syndrome: from anorexia at birth to excessive weight gain preceding hyperphagia, and early severe obesity with hormonal deficiencies, behavioural problems, and dysautonomia. Growth hormone deficiency, hypogonadism, hypothyroidism, premature adrenarche, corticotropin deficiency, precocious puberty, and glucose metabolism disorders are the main endocrine dysfunctions observed. Additionally, as a result of hypothalamic dysfunction, oxytocin and ghrelin systems are impaired in most patients. Standard pituitary and gonadal hormone replacement therapies are required. In this Review, we discuss Prader-Willi syndrome as a model of hypothalamic dysfunction, and provide a comprehensive description of the accumulated knowledge on genetics, pathophysiology, and treatment approaches of this rare disorder.

What can we learn from PWS and SNORD116 genes about the pathophysiology of addictive disorders?

Addictive disorders have been much investigated and many studies have underlined the role of environmental factors such as social interaction in the vulnerability to and maintenance of addictive behaviors. Research on addiction pathophysiology now suggests that certain behavioral disorders are addictive, one example being food addiction. Yet, despite the growing body of knowledge on addiction, it is still unknown why only some of the individuals exposed to a drug become addicted to it. This observation has prompted the consideration of genetic heritage, neurodevelopmental trajectories, and gene-environment interactions in addiction vulnerability. Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder in which children become addicted to food and show early social impairment. PWS is caused by the deficiency of imprinted genes located on the 15q11-q13 chromosome. Among them, the SNORD116 gene was identified as the minimal gene responsible for the PWS phenotype. Several studies have also indicated the role of the Snord116 gene in animal and cellular models to explain PWS pathophysiology and phenotype (including social impairment and food addiction). We thus present here the evidence suggesting the potential involvement of the SNORD116 gene in addictive disorders.

Management of ocular involvement in the acute phase of Stevens-Johnson syndrome and toxic epidermal necrolysis: french national audit of practices, literature review, and consensus agreement

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) can lead to severe ophthalmologic sequelae. The main risk factor is the severity of the initial ocular involvement. There are no recommendations for ocular management during acute phase.

We conducted a national audit of current practice in the 11 sites of the French reference center for toxic bullous dermatoses and a review of the literature to establish therapeutic consensus guidelines. We sent a questionnaire on ocular management practices in SJS/ TEN during acute phase to ophthalmologists and dermatologists. The survey focused on ophthalmologist opinion, pseudomembrane removal, topical ocular treatment (i.e. corticosteroids, antibiotics, antiseptics, artificial tear eye drops, vitamin A ointment application), amniotic membrane transplantation, symblepharon ring use, and systemic corticosteroid therapy for ophthalmologic indication. Nine of 11 centers responded. All requested prompt ophthalmologist consultation. The majority performed pseudomembrane removal, used artificial tears, and vitamin A ointment (8/9, 90%). Combined antibiotic-corticosteroid or corticosteroid eye drops were used in 6 centers (67%), antibiotics alone and antiseptics in 3 centers (33%). Symblepharon ring was used in 5 centers (55%) if necessary. Amniotic membrane transplantation was never performed systematically and only according to the clinical course. Systemic corticosteroid therapy was occasionally used (3/9, 33%) and discussed on a case-by-case basis.

The literature about ocular management practice in SJS/ TEN during acute phase is relatively poor. The role of specific treatments such as local or systemic corticosteroid therapy is not consensual. The use of preservatives, often present in eye drops and deleterious to the ocular surface, is to be restricted. Early amniotic membrane transplantation seems to be promising.

Incidence and risk factors for dupilumab associated ocular adverse events: a real-life prospective study

BACKGROUND

Dupilumab is approved for use in moderate-to-severe atopic dermatitis (AD) and as an add-on maintenance treatment in patients suffering from severe asthma with type 2 inflammation. Ocular adverse events (OAEs) have been reported with dupilumab almost exclusively in patients treated for AD.

OBJECTIVES

The objectives of this study were to describe the incidence and nature of dupilumab-induced OAEs and to assess the potential predisposing factors.

PATIENTS AND METHODS

We conducted a prospective, single-centre, real-life study in adult AD patients treated with dupilumab, who were systematically examined by an ophthalmologist before and during treatment.

RESULTS

Forty-six patients were included prospectively with a median age of 41.1 years and a median initial SCOring Atopic Dermatitis of 46.0 (IQR: 34.5-55.5). OAEs concerned 34.8% of patients and were mostly of mild to moderate severity. Two patients had to discontinue treatment due to OAE. The majority of patients developed or aggravated dry eye disease, with superficial punctate keratitis (SPK). Six patients developed conjunctivitis. Dupilumab-induced OAEs were associated with the following pre-existing parameters: dry eye disease with SPK (Odds ratio (OR); 6.3 [95% confidence interval (CI): 1.3-31.6]), eyelid eczema (OR: 8.7 [95%CI: 1.8-40.6]), history of food allergy (OR 3.8 (95% CI: 1.002-14,070) and IgE serum level> 1000 kU/L (OR:10.6 [CI 95%: 1.2-91.3]).

CONCLUSION

Atopic dermatitis patients with eyelid eczema or dry eye disease symptoms may be referred to an ophthalmologist before starting dupilumab to consider initiating preventive eye hydration measures. Further multicentric and translational studies are warranted to better explain OAEs pathophysiology.

Acquired von Willebrand's syndrome caused by primary hypothyroidism in a 5-year-old girl

Background Acquired von Willebrand's syndrome (aVWS) associated with hypothyroidism is rare in children and more often diagnosed during the peripubertal period in the context of Hashimoto's thyroiditis. Case presentation A 5-year-old girl was referred to the paediatric haematology unit for rectal bleeding, anaemia and prolonged activated partial thromboplastin time (aPTT). Her developmental and learning skills were normal. The physical examination revealed severe short stature (height SDS: -3.6) with overweight (body mass index SDS: 1.8) and clinical sign of hypothyroidism. Laboratory investigation revealed aVWS type 1 associated with severe primary hypothyroidism. Anti-thyroid antibodies were negative and thyroid ultrasound found thyroid hypoplasia in favour of congenital hypothyroidism. Restoration of euthyroidism was associated with increased growth velocity and normalisation of coagulation parameters. Conclusion This report highlights the importance of excluding an underlying pathology (including hypothyroidism) in children with suspected VWS, even in young age.

Causes of death in Prader-Willi syndrome: lessons from 11 years' experience of a national reference center

Background

In the last 20 years, substantial improvements have been made in the diagnosis, treatment and management of patients with Prader-Willi syndrome (PWS). Few data on causes of death are available since those improvements were made. Our study assessed the causes of death among French patients with PWS over the first 11 years of experience of the nationwide French Reference Center for PWS (FRC-PWS).

Methods

Our study relied on two sources of mortality information at national level between 2004 and 2014: The French Epidemiological Centre for the Medical Causes of Death (CépiDc) Registry and the FRC-PWS database. Causes of death were classified into seven categories: respiratory, cardiovascular, gastrointestinal, severe infection, sudden death, other causes, and unknown. Descriptive statistics were calculated separately for children (< 18 years-old) and adults (≥18 years-old).

Results

One hundred and four deaths were identified in France from 2004 to 2014. The median age at death was 30 years, ranging from less than 1 month to 58 years. Seventeen deaths occurred in patients under 18 years, with 70% of them in children under 2 years. Respiratory causes accounted for more than 50% of the deaths in patients with PWS in both children and adults. Both cause and age of death did not significantly differ according to gender or genetic subtype.

Conclusions

Patients with PWS die prematurely due to a respiratory cause in most cases at all ages. In those adult patients with data on obesity, 98% were reported to be obese.