IMPROVE 2022 International Meeting on Pathway-Related Obesity: Vision of Excellence.

Nearly 90 clinicians and researchers from around the world attended the first IMPROVE 2022 International Meeting on Pathway-Related Obesity. Delegates attended in person or online from across Europe, Argentina and Israel to hear the latest scientific and clinical developments in hyperphagia and severe, early-onset obesity, and set out a vision of excellence for the future for improving the diagnosis, treatment, and care of patients with melanocortin-4 receptor (MC4R) pathway-related obesity. The meeting co-chair Peter Kühnen, Charité Universitätsmedizin Berlin, Germany, indicated that change was needed with the rapidly increasing prevalence of obesity and the associated complications to improve the understanding of the underlying mechanisms and acknowledge that monogenic forms of obesity can play an important role, providing insights that can be applied to a wider group of patients with obesity. World-leading experts presented the latest research and led discussions on the underlying science of obesity, diagnosis (including clinical and genetic approaches such as the role of defective MC4R signalling), and emerging clinical data and research with targeted pharmacological approaches. The aim of the meeting was to agree on the questions that needed to be addressed in future research and to ensure that optimised diagnostic work-up was used with new genetic testing tools becoming available. This should aid the planning of new evidence-based treatment strategies for the future, as explained by co-chair Martin Wabitsch, Ulm University Medical Center, Germany.

Hyperphagia and impulsivity: use of self-administered Dykens' and in-house impulsivity questionnaires to characterize eating behaviors in children with severe and early-onset obesity.

BACKGROUND: The determinants of early-onset obesity (< 6 years) are not completely elucidated, however eating behavior has a central role. To date no study has explored eating behavior in children with severe, early-onset obesity. Self-administered questionnaire data from these children were examined to evaluate eating behavior and the etiology of early-onset obesity. METHODS: Children with severe, early-onset obesity (body mass index [BMI] > International Obesity Task Force [IOTF] 30) of different etiologies (hypothalamic obesity [HO], intellectual disability with obesity [IDO], common polygenic obesity [CO]) were prospectively included. BMI history and responses from the Dykens' Hyperphagia Questionnaire and an in-house Impulsivity Questionnaire at first visit were compared between groups. RESULTS: This cohort of 75 children (39 girls; mean age ± standard deviation [SD] 10.8 ± 4.4 years) had severe, early-onset obesity at an age of 3.8 ± 2.7 years, with a BMI Z-score of 4.9 ± 1.5. BMI history varied between the 3 groups, with earlier severe obesity in the HO group versus 2 other groups (BMI > IOTF40 at 3.4 ± 1.6 vs. 4.6 ± 1.6 and 8.4 ± 4.1 years for the IDO and CO groups, respectively [P < 0.01]). Absence of adiposity rebound was more prevalent in the HO group (87% vs. 63% and 33% for the IDO and CO groups, respectively [P < 0.01]). The Dykens' mean total score for the cohort was 22.1 ± 7.2 with no significant between-group differences. Hyperphagia (Dykens' score > 19) and impulsivity (score > 7) were found in 50 (67%) and 11 children (15%), respectively, with no difference between the HO, IDO and CO groups regarding the number of patients with hyperphagia (10 [67%], 14 [74%], and 26 [63%] children, respectively) or impulsivity (2 [13%], 1 [7%], and 8 [19%] children, respectively). Children with food impulsivity had significantly higher total and severity scores on the Dykens' Questionnaire versus those without impulsivity. CONCLUSION: The Dykens' and Impulsivity questionnaires can help diagnose severe hyperphagia with/without food impulsivity in children with early-onset obesity, regardless of disease origin. Their systematic use can allow more targeted management of food access control in clinical practice and monitor the evolution of eating behavior in the case of innovative therapeutic targeting hyperphagia.

Bariatric procedures including Roux-en-Y gastric bypass in French adolescents.

INTRODUCTION: In France, approximately 100 obese adolescents undergo a bariatric procedure every year. To date, only data from laparoscopic adjustable gastric banding (LAGB) or sleeve gastrectomy (SG) have been published. Our objective was to report the outcomes of a series of French obese adolescents who underwent a Roux-en-Y gastric bypass (RYGB). METHODS: We included all obese adolescents aged 13-19 years who underwent RYGB in our department from 2008 with at least 2 years of follow-up after surgery. We analyzed the course of the anthropometric data, comorbidities, and subsequent adverse events. RESULTS: Starting in September 2008, out of 93 obese adolescents who requested bariatric surgery, 39 (35%) underwent a bariatric procedure. From these adolescents, 2-year follow-up data were available for 26 patients who had a RYGB. At the time of surgery, the mean patient age was 17.4 years (standard deviation [SD]=1.4) and the body mass index (BMI) was 52.0 kg/m² (SD=7.8). One patient was lost to follow-up. At 2 years after surgery,  the mean BMI was 35.7 kg/m² (SD=9.4) with a mean decrease in BMI of 31.9% (SD=11.6). Comorbidities improved for most of the patients: high blood pressure (2/2) and pseudotumor cerebri (1/1) were cured after surgery, and dyslipidemia improved globally. The complications observed were anemia, abdominal pain requiring celioscopy (n = 2), and oxalic nephrolithiasis. CONCLUSION: Only one third of the obese adolescents requesting bariatric surgery were operated on. Our series including exclusively obese adolescents who underwent an RYGB presents the results of this technique on weight loss and comorbidities; mechanical and nutritional complications remain uncommon. These results are similar to those obtained in studies of adult patients.

Current Treatments for Patients with Genetic Obesity

Obesity derives from impaired central control of body weight, implying interaction between environment and an individual genetic predisposition. Genetic obesities, including monogenic and syndromic obesities, are rare and complex neuro-endocrine pathologies where the genetic contribution is predominant. Severe and early-onset obesity with eating disorders associated with frequent comorbidities make these diseases challenging. Their current estimated prevalence of 5-10% in severely obese children is probably underestimated due to the limited access to genetic diagnosis. A central alteration of hypothalamic regulation of weight implies that the leptin-melanocortin pathway is responsible for the symptoms. The management of genetic obesity has so far been only based, above all, on lifestyle intervention, especially regarding nutrition and physical activity. New therapeutic options have emerged in the last years for these patients, raising great hope to manage their complex situation and improve quality of life. Implementation of genetic diagnosis in clinical practice is thus of paramount importance to allow individualized care. This review describes the current clinical management of genetic obesity and the evidence on which it is based. Some insights will also be provided into new therapies under evaluation.

Novel therapeutics in rare genetic obesities: A narrative review.

The better understanding of the molecular causes of rare genetic obesities and its associated phenotype involving the hypothalamus allows today to consider innovative therapeutics focused on hunger control. Several new pharmacological molecules benefit patients with monogenic or syndromic obesity. They are likely to be among the treatment options for these patients in the coming years, helping clinicians and patients prevent rapid weight progression and eventually limit bariatric surgery procedures, which is less effective in these patients. Their positioning in the management of such patients will be needed to be well defined to develop precision medicine in genetic forms of obesity.

Prevalence and Etiologies of Renal and Urinary Manifestations in a Large Cohort of Children With Inflammatory Bowel Disease.

BACKGROUND AND OBJECTIVES: Renal and/or urinary manifestations (RUM) have been reported in pediatric patients with inflammatory bowel disease (IBD) but their incidence is unknown. The aims of this study were to assess the prevalence and causes of these manifestations in children with IBD and determine the causal link with 5-aminosalicylic acid (5-ASA) treatment. METHODS: A retrospective observational study was performed with children with diagnosis of IBD. All children with RUM during follow-up and/or impaired renal function [estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m 2 ] were identified. RESULTS: Of 228 included patients, 9 (3.9%) had a RUM during follow-up [follow-up: 5 years (1-12 years)] at a median age of 16 years (8-17 years). It concerned 7 of 171 patients with Crohn disease and 2 of 57 with ulcerative colitis. Seven patients were taking 5-ASA at the time of the RUM. Only 1 of them had an iatrogenic renal complication related to this treatment. Patients with RUM had a more severe disease with increased anti-tumor necrosis factor-α use ( P = 0.031), more abscesses ( P = 0.003), and a higher rate of digestive surgery ( P = 0.04). For the whole cohort, a significant decrease in eGFR was found during follow-up (121 vs 107 mL/min/1.73 m 2 , P < 0.001). At the end of follow-up, 38 of 202 (19%) patients had an eGFR < 90 mL/min/1.73 m 2 . CONCLUSION: In children with IBD, RUM can occur, independently of treatment with 5-ASA. During follow-up, a significant decrease in eGFR was observed. We suggest monitoring renal function in all patients with IBD.

Rare genetic causes of obesity: Diagnosis and management in clinical care.

Rare genetic forms of obesity are linked to impaired energy balance (i.e., eating behaviour and energy expenditure) involving hypothalamic pathways. More than 60 genes coding for proteins located in the hypothalamic leptin/melanocortin pathway contribute to the development of these rare forms of obesity. The ambition of the French National Protocol for the Diagnosis and Care (PNDS) of Obesity of Rare Causes was to establish practical recommendations for assessment and management at all ages. This report is available on the website of the French Health Authority (HAS). In addition to severe obesity, patients often display obesity-related comorbidities and neuropsychological/psychiatric disorders. These complex conditions make clinical management particularly challenging. Early diagnosis is critical for the organization of coordinated specialized multidisciplinary care, with mandatory interaction between caregivers, social partners and families. Strategies to prevent aggravation of obesity consist in limiting access to food, establishing a reassuring daily eating environment, and the practice of sustained adapted supervised daily physical activity. The implementation of genetic diagnosis in clinical practice now enables a personalized medicine approach with access to new drug therapies, and improves the analysis of the risk/benefit ratio of bariatric surgery.

Pediatric Home Parenteral Nutrition in France: A six years national survey.

BACKGROUND AND AIMS: Home Parenteral Nutrition (HPN) is the cornerstone management for children suffering from chronic intestinal failure (CIF). In France, HPN is organized from a network of 7 certified centers located in University Hospitals spread across the national territory. This study aims to review the data involving children on HPN over a 6-years period in France to outline the global and continuous improvement in care. PATIENTS AND METHODS: This cross-sectional study included all children enrolled in any of the 7 French HPN certified centers from January 1st, 2014 to December 31st, 2019. Data was recorded from annual databases provided by each center regarding: age at inclusion, indication and duration of HPN, type of intravenous lipid emulsion (ILE), outcome [PN weaning off, transfer to adult center, death, intestinal transplantation (ITx)], rate of catheter-related bloodstream infections (CRSBIs) for 1000 days of HPN, Taurolidine lock procedure (TLP) use and prevalence of cholestasis defined as conjugated bilirubin ≥20 µmol/l. RESULTS: The number of patients increased by 43.6% from 268 in 2014 to 385 in 2019. According to the year of follow up, the indications for HPN were short bowel syndrome (SBS) (42.3-46.6%), congenital enteropathies (CE) (18.5-22.8%), chronic intestinal pseudo-obstruction syndrome (CIPOS) (13.0-16.3%), long segment Hirschsprung's disease (LSHD) (9.7-13.3%), Crohn's disease (CD) (1.6-2.6%) and other non-primary digestive diseases (NPDD) such as immune deficiency, cancer or metabolic disease (4.0-9.2%). The median age at discharge on HPN decreased from 11.7 months in 2014 to 8.3 months in 2019 (p < .001). By December 31st, 2019, 44.8% of children had left the HPN program after a median duration ranging between 39.9 and 66.4 months. Among these patients, 192 (74.2%) were weaned off PN (94.7% SBS), 41 (15.8%) were transferred to adult centers for CIPOS (42%), SBS (31%) or CE (27%), 21 died (8.1%) - mostly in relation to cancer or immune deficiency - and 5 were transplanted (1.9%): 4 underwent combined liver-intestine transplantation for LSHD (n = 2), SBS, CE and one multivisceral Tx for CIPOS. The use of a composite fish-oil based ILE increased from 67.4% in 2014 to 88.3% in 2019 (p < 0.001). CRBSIs dropped from 1.04 CRSBIs per 1000 days HPN in 2014 to 0.61 in 2019 (p < 0.001) while meantime, the percentage of children receiving TLP increased from 29.4% to 63.0% (p < 0.001). The prevalence of cholestasis (conjugated bilirubin ≥ 20 µmol/l) was low and stable between 4.1 and 5.9% of children during the study period. CONCLUSION: In France, the number of children enrolled in a HPN program continuously increased over a 6 years period. SBS is the leading cause of CIF requiring HPN. The rate of CRBSIs dropped dramatically as the use of TLP increased. Mortality rate was low and mainly in relation to the underlying disease (cancer, immune deficiency). Cholestasis and intestinal Tx remained very rare.

Long-term outcomes of bariatric surgery in patients with bi-allelic mutations in the POMC, LEPR, and MC4R genes.

BACKGROUND: Gene mutations in the leptin-melanocortin signaling cascade lead to hyperphagia and severe early onset obesity. In most cases, multimodal conservative treatment (increased physical activity, reduced caloric intake) is not successful to stabilize body weight and control hyperphagia. OBJECTIVES: To examine bariatric surgery as a therapeutic option for patients with genetic obesity. SETTING: Three major academic, specialized medical centers. METHODS: In 3 clinical centers, we retrospectively analyzed the outcomes of bariatric surgery performed in 8 patients with monogenic forms of obesity with bi-allelic variants in the genes LEPR (n = 5), POMC (n = 2), and MC4R (n = 1). RESULTS: In this group of patients with monogenic obesity, initial bariatric surgery was performed at a median age of 19 years (interquartile range [IQR], 16-23.8 yr). All patients initially experienced weight loss after each bariatric surgery, which was followed by substantial weight regain. In total, bariatric surgery led to a median maximum reduction of body weight of -21.5 kg (IQR, -36.3 to -2.9 kg), median percent excess weight loss (%EWL) of -47.5 %EWL (IQR, -57.6 to -28.9 %EWL). This body weight reduction was followed by median weight regain of 24.1 kg (IQR: 10.0 to 42.0 kg), leading to a final weight change of -24.2 % EWL (IQR: -37.6 to -5.4 %EWL) after a maximum duration of 19 years post surgery. In one patient, bariatric surgery was accompanied by significant complications, including vitamin deficiencies and hernia development. CONCLUSION: The indication for bariatric surgery in patients with monogenic obesity based on bi-allelic gene mutations and its benefit/risk balance has to be evaluated very cautiously by specialized centers. Furthermore, to avoid an unsuccessful operation, preoperative genetic testing of patients with a history of early onset obesity might be essential, even more since novel pharmacological treatment options are expected.

Intermediate-Term Efficacy and Tolerance of Statins in Children.

OBJECTIVES: To evaluate the intermediate-term efficacy and tolerance of statins in children and adolescents with familial hypercholesterolemia. STUDY DESIGN: A total of 131 children or adolescents treated with statins for familial hypercholesterolemia were prospectively included. The efficacy of treatment was established by the percentage of children who achieved low density lipoprotein-cholesterol (LDL-C) levels <160 mg/dL during treatment. Treatment tolerance was evaluated by the occurrence of clinical or laboratory side effects, regularity of increases in height and weight, and pubertal development. RESULTS: The median duration of treatment with statins was 4 years. A median decrease of 32% in LDL-C levels was observed (P < .0001). The therapeutic target (LDL-C <160 mg/dL) was achieved in 67% of cases. Increases in height and weight and sexual maturation were not affected by the treatment. Minor side effects were reported for 24 (18.4%) patients including 3 cases of a clinically asymptomatic increase in creatine phosphokinase (CPK) levels, 2 cases of an increase in CPK levels with muscular symptoms, 14 cases of myalgia without an increase in CPK levels, 3 cases of abdominal pain, 1 case of dysuria, and 1 case of diffuse pain. None of these side effects led to the discontinuation of statin therapy, although a change of statin was required in 7 cases. This new statin was tolerated in all cases. No patients had abnormal liver function during treatment. CONCLUSIONS: The results of this large cohort confirm the intermediate-term safety and efficacy of statin therapy in children with familial hypercholesterolemia.

Experience of Using a Semielemental Formula for Home Enteral Nutrition in Children: A Multicenter Cross-sectional Study.

OBJECTIVES: The use of semielemental diets concerns a small proportion of children on enteral nutrition whose characteristics have never been reported. Our aim was to describe a cohort of patients on home enteral nutrition with Peptamen Junior, including the tolerance and nutritional efficacy of this product. METHODS: We performed a retrospective multicenter survey on a cohort of patients receiving this semielemental diet at home between 2010 and 2015 in 14 tertiary pediatric French centers. We recorded at baseline, 3, 6, and 12 months, and then every year the anthropometric characteristics of the patients, indications and modalities of administration of the diet, and the tolerance and adverse events. RESULTS: We recruited 136 patients ages 9.8 ±â€Š4.4 years at baseline. Mean body mass index z score was -1.0 ±â€Š1.8; mean height z score was -1.1 ±â€Š1.9. The main underlying diseases were digestive (35.3%), neurological (33.1%), and hematological (19.9%). The indications for a semielemental diet were failure of another diet in 70 patients (51.9%), severe malnutrition in 19 (14.1%), cystic fibrosis in 11 (8.1%), and switch from parenteral nutrition in 11 (8.1%). Side effects were observed in 39.2% of the patients, and required medical attention in 8.2%. Body mass index improved or remained normal in 88.3% of children. CONCLUSIONS: This semielemental diet seems to be well tolerated and efficient in the setting of home enteral nutrition in children with complex diseases featuring malabsorption and/or after failure of polymeric diet.

[Genetics and epigenetics of obesity: keys to understand]. / Génétique et épigénétique de l'obésité : les pistes pour comprendre.

Genetics and epigenetics of obesity: the keys to understand. Obesity is a multifactorial disease due to central dysregulation of energy homeostasis. The contribution of genetics is constant but varies according to the situations from the rare forms of non-syndromic and syndromic monogenic obesities (about 5% of cases) and the socalled polygenic obesity (or common obesity) which is the most frequent situation (95% of cases). Environmental factors (early pre- and post-natal, societal or psychological determinants) always interact closely with the genetic factors of predisposition. The better understanding of these different actors should lead in the future to a real personalized medicine (targeted drug treatments according to the identified genetic anomaly and / or multidisciplinary management or even bariatric surgery according to clinical situations).

Génétique et épigénétique de l'obésité : les pistes pour comprendre. L'obésité est une pathologie complexe multifactorielle considérée comme une maladie des centres régulateurs du poids. La contribution de la génétique est constante mais variable selon les situations, qui comprennent les formes rares d'obésité monogénique non syndromique et syndromique (environ 5 % des obésités) et l'obésité dite polygénique (ou obésité commune) qui est la situation la plus souvent rencontrée (95 % des cas). Les facteurs environnementaux (déterminants précoces pré- et postnataux, sociétaux ou psychologiques) interagissent toujours étroitement avec les facteurs génétiques impliqués. La meilleure compréhension de ces différents acteurs devrait permettre d'aboutir dans le futur à une véritable médecine personnalisée (traitements médicamenteux ciblés selon l'anomalie génétique identifiée et/ou prise en charge globale multidisciplinaire, voire chirurgie bariatrique, selon les situations cliniques).

European paediatric non-alcoholic fatty liver disease registry (EU-PNAFLD): Design and rationale.

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in children and has the potential to progress to advanced fibrosis/cirrhosis, end-stage liver disease and hepatocellular carcinoma. However, the natural history of the condition is poorly understood and there are no approved treatments. The European Paediatric Non-Alcoholic Fatty Liver Disease Registry (EU-PNAFLD) is a multi-centre registry of paediatric NAFLD that will serve as a prospective, observational, natural history study and provide a tractable back-bone to support recruitment into subsequent interventional trials. Collection of samples into a bio-repository will facilitate translational studies, including genome sequencing and metabolomics. EU-PNAFLD will work closely alongside the existing adult European NAFLD Registry to obtain data on clinical outcomes after 20-30 years. Through an international, well-characterised large-scale cohort, EU-PNAFLD will address the key questions in paediatric NAFLD and benefit patients with the condition.

Diagnosis and management of Silver-Russell syndrome: first international consensus statement.

This Consensus Statement summarizes recommendations for clinical diagnosis, investigation and management of patients with Silver-Russell syndrome (SRS), an imprinting disorder that causes prenatal and postnatal growth retardation. Considerable overlap exists between the care of individuals born small for gestational age and those with SRS. However, many specific management issues exist and evidence from controlled trials remains limited. SRS is primarily a clinical diagnosis; however, molecular testing enables confirmation of the clinical diagnosis and defines the subtype. A 'normal' result from a molecular test does not exclude the diagnosis of SRS. The management of children with SRS requires an experienced, multidisciplinary approach. Specific issues include growth failure, severe feeding difficulties, gastrointestinal problems, hypoglycaemia, body asymmetry, scoliosis, motor and speech delay and psychosocial challenges. An early emphasis on adequate nutritional status is important, with awareness that rapid postnatal weight gain might lead to subsequent increased risk of metabolic disorders. The benefits of treating patients with SRS with growth hormone include improved body composition, motor development and appetite, reduced risk of hypoglycaemia and increased height. Clinicians should be aware of possible premature adrenarche, fairly early and rapid central puberty and insulin resistance. Treatment with gonadotropin-releasing hormone analogues can delay progression of central puberty and preserve adult height potential. Long-term follow up is essential to determine the natural history and optimal management in adulthood.

Deficiency in prohormone convertase PC1 impairs prohormone processing in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is caused by a loss of paternally expressed genes in an imprinted region of chromosome 15q. Among the canonical PWS phenotypes are hyperphagic obesity, central hypogonadism, and low growth hormone (GH). Rare microdeletions in PWS patients define a 91-kb minimum critical deletion region encompassing 3 genes, including the noncoding RNA gene SNORD116. Here, we found that protein and transcript levels of nescient helix loop helix 2 (NHLH2) and the prohormone convertase PC1 (encoded by PCSK1) were reduced in PWS patient induced pluripotent stem cell-derived (iPSC-derived) neurons. Moreover, Nhlh2 and Pcsk1 expression were reduced in hypothalami of fasted Snord116 paternal knockout (Snord116p-/m+) mice. Hypothalamic Agrp and Npy remained elevated following refeeding in association with relative hyperphagia in Snord116p-/m+ mice. Nhlh2-deficient mice display growth deficiencies as adolescents and hypogonadism, hyperphagia, and obesity as adults. Nhlh2 has also been shown to promote Pcsk1 expression. Humans and mice deficient in PC1 display hyperphagic obesity, hypogonadism, decreased GH, and hypoinsulinemic diabetes due to impaired prohormone processing. Here, we found that Snord116p-/m+ mice displayed in vivo functional defects in prohormone processing of proinsulin, pro-GH-releasing hormone, and proghrelin in association with reductions in islet, hypothalamic, and stomach PC1 content. Our findings suggest that the major neuroendocrine features of PWS are due to PC1 deficiency.

Rare Genetic Forms of Obesity: Clinical Approach and Current Treatments in 2016.

Obesity results from a synergistic relationship between genes and the environment. The phenotypic expression of genetic factors involved in obesity is variable, allowing to distinguish several clinical pictures of obesity. Monogenic obesity is described as rare and severe early-onset obesity with abnormal feeding behavior and endocrine disorders. This is mainly due to autosomal recessive mutations in genes of the leptin-melanocortin pathway which plays a key role in the hypothalamic control of food intake. Melanocortin 4 receptor(MC4R)-linked obesity is characterized by the variable severity of obesity and no notable additional phenotypes. Mutations in the MC4R gene are involved in 2-3% of obese children and adults; the majority of these are heterozygous. Syndromic obesity is associated with mental retardation, dysmorphic features, and organ-specific developmental abnormalities. Additional genes participating in the development of hypothalamus and central nervous system have been regularly identified. But to date, not all involved genes have been identified so far. New diagnostic tools, such as whole-exome sequencing, will probably help to identify other genes. Managing these patients is challenging. Indeed, specific treatments are available only for specific types of monogenic obesity, such as leptin deficiency. Data on bariatric surgery are limited and controversial. New molecules acting on the leptin-melanocortin pathway are currently being developed.

Global molecular analysis and APOE mutations in a cohort of autosomal dominant hypercholesterolemia patients in France.

Autosomal dominant hypercholesterolemia (ADH) is a human disorder characterized phenotypically by isolated high-cholesterol levels. Mutations in the low density lipoprotein receptor (LDLR), APOB, and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes are well known to be associated with the disease. To characterize the genetic background associated with ADH in France, the three ADH-associated genes were sequenced in a cohort of 120 children and 109 adult patients. Fifty-one percent of the cohort had a possible deleterious variant in LDLR, 3.1% in APOB, and 1.7% in PCSK9. We identified 18 new variants in LDLR and 2 in PCSK9. Three LDLR variants, including two newly identified, were studied by minigene reporter assay confirming the predicted effects on splicing. Additionally, as recently an in-frame deletion in the APOE gene was found to be linked to ADH, the sequencing of this latter gene was performed in patients without a deleterious variant in the three former genes. An APOE variant was identified in three patients with isolated severe hypercholesterolemia giving a frequency of 1.3% in the cohort. Therefore, even though LDLR mutations are the major cause of ADH with a large mutation spectrum, APOE variants were found to be significantly associated with the disease. Furthermore, using structural analysis and modeling, the identified APOE sequence changes were predicted to impact protein function.

Seven novel deleterious LEPR mutations found in early-onset obesity: a ΔExon6-8 shared by subjects from Reunion Island, France, suggests a founder effect.

CONTEXT: Infrequent mutations have been reported in the leptin receptor (LEPR) gene in humans with morbid obesity and endocrine disorders. However LEPR mutations are rarely examined in large populations from different ethnicities in a given country. OBJECTIVE: We estimated the prevalence of LEPR mutations in French patients with severe obesity and evaluated mutated patients' phenotype. DESIGN AND PATIENTS: We sequenced the LEPR gene in 535 morbidly obese French participants. We conducted clinical investigations to determine whether individuals with a novel shared mutation display particular characteristics relative to obesity history, body composition, hormonal functions, and the outcome of bariatric surgery. RESULTS: We identified 12 patients with a novel LEPR mutation (p.C604G, p.L786P, p.H800_N831del, p.Y422H, p.T711NfsX18, p.535-1G>A, p.P166CfsX7). Six unrelated subjects were carriers of the p.P166CfsX7 mutation leading to deletion overlapping exons 6 to 8. All subjects originated from Reunion Island (France). Their clinical features (severe early-onset obesity, food impulsivity, and hypogonadotropic hypogonadism) did not differ from other new LEPR mutation carriers. Results concerning weight loss surgery were inconsistent in homozygous LEPR mutation carriers. Heterozygous LEPR mutation carriers exhibited variable severity of obesity and no endocrine abnormality. CONCLUSION: Among seven newly discovered LEPR mutations in this French obese population, we identified a LEPR frameshift mutation shared by six subjects from Reunion Island. This observation suggests a founder effect in this Indian Ocean island with high prevalence of obesity and supports a recommendation for systematic screening for this mutation in morbidly obese subjects in this population.

[Bariatric and plastic surgery in obese adolescents: an alternative treatment]. / Chirurgie bariatrique et esthétique de l'adolescent obèse : une thérapeutique alternative.

The increased frequency of extreme forms of obesity in adolescents and the disappointing results of conventional treatments are now leading pediatricians to consider bariatric or cosmetic surgery as the only real long-term effective therapeutic alternative. The two main techniques currently used for bariatric surgery in adolescents are gastric bypass and adjustable gastric banding. Whatever the technique, weight loss is significant with improvement of comorbidities and quality of life. In addition, the complications are identical to those in adults and equally frequent. However, because of the particularities of this age, caution is still required. Adolescence is indeed characterized by specific nutritional needs, but also changes in body image in which surgery could have a negative effect. Currently, all obese teenagers making a request for bariatric surgery should have a comprehensive assessment with global care for at least 6 months. The indication is then discussed on a case-by-case basis by multidisciplinary teams and experts. To date, the type of surgery (gastric banding, gastric sleeve, or bypass) is still widely discussed. Based on experience with adults, we believe that gastric sleeve and bypass should be preferred. In addition, obesity in adolescents almost always involves psychosocial consequences, while somatic complications are rare. Thus, the care of adipo- or gynecomastia, abdominal fat excess, and concealed penis is essential and therefore justifies cosmetic surgery.