Monozygotic twins discordant for ROHHAD phenotype

Anti-ZSCAN1 Autoantibodies Are a Feasible Diagnostic Marker for ROHHAD Syndrome Not Associated with a Tumor

Recent studies have reported the presence of autoantibodies against zinc finger and SCAN domain-containing protein 1 (ZSCAN1) in the sera of patients with rapid-onset obesity with hypoventilation, hypothalamic and autonomic dysregulation (ROHHAD) syndrome associated with neuroendocrine tumors, suggesting immunologic and paraneoplastic processes as the pathologic underpinnings. Moreover, several hypothalamic regions, including the subfornical organ (SFO), were reported to exhibit antibody reactivity in a patient with ROHHAD syndrome not associated with a tumor. Whether ROHHAD syndrome not associated with a tumor is associated with anti-ZSCAN1 autoantibodies remains unclear. We used a comprehensive protein array analysis to identify candidate molecules in the sera of patients with ROHHAD syndrome and identified ZSCAN1 as a target antigen. We also found that ZSCAN1 was co-expressed at the site of antibody reactivity to the IgG in the patient serum observed in mouse SFOs and an enzyme-linked immunosorbent assay showed that >85% of the patients with ROHHAD syndrome were positive for anti-ZSCAN1 autoantibodies. These results suggest anti-ZSCAN1 autoantibodies as a feasible diagnostic marker in ROHHAD syndrome regardless of the presence of a tumor.

Genetics and epigenetics in the obesity phenotyping scenario

Obesity is a common complex trait that elevates the risk for various diseases, including type 2 diabetes and cardiovascular disease. A combination of environmental and genetic factors influences the pathogenesis of obesity. Advances in genomic technologies have driven the identification of multiple genetic loci associated with this disease, ranging from studying severe onset cases to investigating common multifactorial polygenic forms. Additionally, findings from epigenetic analyses of modifications to the genome that do not involve changes to the underlying DNA sequence have emerged as key signatures in the development of obesity. Such modifications can mediate the effects of environmental factors, including diet and lifestyle, on gene expression and clinical presentation. This review outlines what is known about the genetic and epigenetic contributors to obesity susceptibility, along with the albeit limited therapeutic options currently available. Furthermore, we delineate the potential mechanisms of actions through which epigenetic changes can mediate environmental influences and the related opportunities they present for future interventions in the management of obesity.

Whole genome sequencing in ROHHAD trios proved inconclusive: what's beyond?

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD) is a rare, life-threatening, pediatric disorder of unknown etiology, whose diagnosis is made difficult by poor knowledge of clinical manifestation, and lack of any confirmatory tests. Children with ROHHAD usually present with rapid onset weight gain which may be followed, over months or years, by hypothalamic dysfunction, hypoventilation, autonomic dysfunction, including impaired bowel motility, and tumors of neural crest origin. Despite the lack of evidence of inheritance in ROHHAD, several studies have been conducted in recent years that have explored possible genetic origins, with unsuccessful results. In order to broaden the search for possible genetic risk factors, an attempt was made to analyse the non-coding variants in two trios (proband with parents), recruited in the Gaslini Children's Hospital in Genoa (Italy). Both patients were females, with a typical history of ROHHAD. Gene variants (single nucleotide variants, short insertions/deletions, splice variants or in tandem expansion of homopolymeric tracts) or altered genomic regions (copy number variations or structural variants) shared between the two probands were searched. Currently, we have not found any potentially pathogenic changes, consistent with the ROHHAD clinical phenotype, and involving genes, regions or pathways shared between the two trios. To definitively rule out the genetic etiology, third-generation sequencing technologies (e.g., long-reads sequencing, optical mapping) should be applied, as well as other pathways, including those associated with immunological and autoimmune disorders, should be explored, making use not only of genomics but also of different -omic datasets.

Case report: Molecular characterisation of adipose-tissue derived cells from a patient with ROHHAD syndrome

There have been over 100 cases of Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome reported, but there is currently no curative treatment for children with this condition. We aimed to better characterise adipose cells from a child with ROHHAD syndrome. We isolated pre-adipocytes from a 4 year-old female patient with ROHHAD syndrome and assessed proliferation rate of these cells. We evaluated levels of DLP-Pref-1(pre-adipocyte marker) using western blotting, and concentrations of interleukin-6(IL-6) using ELISA. We performed next-generation sequencing (NGS) and bioinformatic analyses on these cells compared to tissue from an age/sex-matched control. The two most up-/down-regulated genes were validated using QPCR. We successfully isolated pre-adipocytes from a fat biopsy, by confirming the presence of Pref-1 and differentiated them to mature adipocytes. Interleukin 6, (Il-6) levels were 5.6-fold higher in ROHHAD cells compared to a control age/sex-matched biopsy. NGS revealed 25,703 differentially expressed genes (DEGs) from ROHHAD cells vs. control of which 2,237 genes were significantly altered. The 20 most significantly up/down-regulated genes were selected for discussion. This paper describes the first transcriptomic analysis of adipose cells from a child with ROHHAD vs. normal control adipose tissue as a first step in identifying targetable pathways/mechanisms underlying this condition with novel therapeutic interventions.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): a collaborative review of the current understanding

PURPOSE

To provide an overview of the discovery, presentation, and management of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD). To discuss a search for causative etiology spanning multiple disciplines and continents.

METHODS

The literature (1965-2022) on the diagnosis, management, pathophysiology, and potential etiology of ROHHAD was methodically reviewed. The experience of several academic centers with expertise in ROHHAD is presented, along with a detailed discussion of scientific discovery in the search for a cause.

RESULTS

ROHHAD is an ultra-rare syndrome with fewer than 200 known cases. Although variations occur, the acronym ROHHAD is intended to alert physicians to the usual sequence or unfolding of the phenotypic presentation, including the full phenotype. Nearly 60 years after its first description, more is known about the pathophysiology of ROHHAD, but the etiology remains enigmatic. The search for a genetic mutation common to patients with ROHHAD has not, to date, demonstrated a disease-defining gene. Similarly, a search for the autoimmune basis of ROHHAD has not resulted in a definitive answer. This review summarizes current knowledge and potential future directions.

CONCLUSION

ROHHAD is a poorly understood, complex, and potentially devastating disorder. The search for its cause intertwines with the search for causes of obesity and autonomic dysregulation. The care for the patient with ROHHAD necessitates collaborative international efforts to advance our knowledge and, thereby, treatment, to decrease the disease burden and eventually to stop, and/or reverse the unfolding of the phenotype.

Analysis and comparisons of gene expression changes in patient- derived neurons from ROHHAD, CCHS, and PWS

Background

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome is an ultra-rare neurocristopathy with no known genetic or environmental etiology. Rapid-onset obesity over a 3-12 month period with onset between ages 1.5-7 years of age is followed by an unfolding constellation of symptoms including severe hypoventilation that can lead to cardiorespiratory arrest in previously healthy children if not identified early and intervention provided. Congenital Central Hypoventilation syndrome (CCHS) and Prader-Willi syndrome (PWS) have overlapping clinical features with ROHHAD and known genetic etiologies. Here we compare patient neurons from three pediatric syndromes (ROHHAD, CCHS, and PWS) and neurotypical control subjects to identify molecular overlap that may explain the clinical similarities.

Methods

Dental pulp stem cells (DPSC) from neurotypical control, ROHHAD, and CCHS subjects were differentiated into neuronal cultures for RNA sequencing (RNAseq). Differential expression analysis identified transcripts variably regulated in ROHHAD and CCHS vs. neurotypical control neurons. In addition, we used previously published PWS transcript data to compare both groups to PWS patient-derived DPSC neurons. Enrichment analysis was performed on RNAseq data and downstream protein expression analysis was performed using immunoblotting.

Results

We identified three transcripts differentially regulated in all three syndromes vs. neurotypical control subjects. Gene ontology analysis on the ROHHAD dataset revealed enrichments in several molecular pathways that may contribute to disease pathology. Importantly, we found 58 transcripts differentially expressed in both ROHHAD and CCHS patient neurons vs. control neurons. Finally, we validated transcript level changes in expression of ADORA2A, a gene encoding for an adenosine receptor, at the protein level in CCHS neurons and found variable, although significant, changes in ROHHAD neurons.

Conclusions

The molecular overlap between CCHS and ROHHAD neurons suggests that the clinical phenotypes in these syndromes likely arise from or affect similar transcriptional pathways. Further, gene ontology analysis identified enrichments in ATPase transmembrane transporters, acetylglucosaminyltransferases, and phagocytic vesicle membrane proteins that may contribute to the ROHHAD phenotype. Finally, our data imply that the rapid-onset obesity seen in both ROHHAD and PWS likely arise from different molecular mechanisms. The data presented here describes important preliminary findings that warrant further validation.

ZSCAN1 Autoantibodies Are Associated with Pediatric Paraneoplastic ROHHAD

OBJECTIVE

Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), is a severe pediatric disorder of uncertain etiology resulting in hypothalamic dysfunction and frequent sudden death. Frequent co-occurrence of neuroblastic tumors have fueled suspicion of an autoimmune paraneoplastic neurological syndrome (PNS); however, specific anti-neural autoantibodies, a hallmark of PNS, have not been identified. Our objective is to determine if an autoimmune paraneoplastic etiology underlies ROHHAD.

METHODS

Immunoglobulin G (IgG) from pediatric ROHHAD patients (n = 9), non-inflammatory individuals (n = 100) and relevant pediatric controls (n = 25) was screened using a programmable phage display of the human peptidome (PhIP-Seq). Putative ROHHAD-specific autoantibodies were orthogonally validated using radioactive ligand binding and cell-based assays. Expression of autoantibody targets in ROHHAD tumor and healthy brain tissue was assessed with immunohistochemistry and mass spectrometry, respectively.

RESULTS

Autoantibodies to ZSCAN1 were detected in ROHHAD patients by PhIP-Seq and orthogonally validated in 7/9 ROHHAD patients and 0/125 controls using radioactive ligand binding and cell-based assays. Expression of ZSCAN1 in ROHHAD tumor and healthy human brain tissue was confirmed.

INTERPRETATION

Our results support the notion that tumor-associated ROHHAD syndrome is a pediatric PNS, potentially initiated by an immune response to peripheral neuroblastic tumor. ZSCAN1 autoantibodies may aid in earlier, accurate diagnosis of ROHHAD syndrome, thus providing a means toward early detection and treatment. This work warrants follow-up studies to test sensitivity and specificity of a novel diagnostic test. Last, given the absence of the ZSCAN1 gene in rodents, our study highlights the value of human-based approaches for detecting novel PNS subtypes. ANN NEUROL 2022;92:279-291.

Evolution of physiologic and autonomic phenotype in rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation over a decade from age at diagnosis

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare cause of syndromic obesity with risk of cardiorespiratory arrest and neural crest tumor. No ROHHAD-specific genetic test exists at present. Rapid weight gain of 20-30 pounds, typically between ages 2-7 years in an otherwise healthy child, followed by multiple endocrine abnormalities herald the ROHHAD phenotype. Vigilant monitoring for asleep hypoventilation (and later awake) is mandatory as hypoventilation and altered control of breathing can emerge rapidly, necessitating artificial ventilation as life support. Recurrent hypoxemia may lead to cor pulmonale and/or right ventricular hypertrophy. Autonomic dysregulation is variably manifest. Here we describe the disease onset with "unfolding" of the phenotype in a child with ROHHAD, demonstrating the presentation complexity, need for a well-synchronized team approach, and optimized management that led to notable improvement ("refolding") in many aspects of the child's ROHHAD phenotype over 10 years of care.

CITATION

Khaytin I, Stewart TM, Zelko FA, et al. Evolution of physiologic and autonomic phenotype in rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation over a decade from age at diagnosis. J Clin Sleep Med. 2022;18(3):937-944.

Images: Sleep-disordered breathing and hypoventilation in a child with obesity and hypothalamic dysfunction

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare and potentially lethal disorder of respiratory control, autonomic, and hypothalamic dysfunction of unknown etiology. We report a 15-year-old girl with ROHHAD who developed hyperphagia and rapid weight gain of 16 kg between 2.5 and 4 years of age and cardiorespiratory arrest at 4 years. Initial polysomnography showed central sleep apnea and severe oxygen desaturations without hypoventilation. Mild obstructive sleep apnea and intermittent hypoxemia were identified at 4.5 years, following which nocturnal bilevel positive airway pressure therapy was initiated. At 6 years, she developed sleep-related hypoventilation, and subsequent polysomnograms continued to show obstructive sleep apnea and hypoventilation requiring bilevel positive airway pressure. Clinicians interpreting polysomnograms should become familiar with the evolution of sleep-disordered breathing in ROHHAD and that hypoventilation may develop over time. Our case highlights the importance of serial polysomnography in patients with ROHHAD and optimal ventilatory management.

CITATION

Ghosh R, Malik M, Daley TC, Kasi AS. Images: Sleep-disordered breathing and hypoventilation in a child with obesity and hypothalamic dysfunction. J Clin Sleep Med. 2022;18(1):339-342.

Developmental disorders affecting the respiratory system: CCHS and ROHHAD

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) and Congenital Central Hypoventilation Syndrome (CCHS) are ultra-rare distinct clinical disorders with overlapping symptoms including altered respiratory control and autonomic regulation. Although both disorders have been considered for decades to be on the same spectrum with necessity of artificial ventilation as life-support, recent acquisition of specific knowledge concerning the genetic basis of CCHS coupled with an elusive etiology for ROHHAD have definitely established that the two disorders are different. CCHS is an autosomal dominant neurocristopathy characterized by alveolar hypoventilation resulting in hypoxemia/hypercarbia and features of autonomic nervous system dysregulation (ANSD), with presentation typically in the newborn period. It is caused by paired-like homeobox 2B (PHOX2B) variants, with known genotype-phenotype correlation but pathogenic mechanism(s) are yet unknown. ROHHAD is characterized by rapid weight gain, followed by hypothalamic dysfunction, then hypoventilation followed by ANSD, in seemingly normal children ages 1.5-7 years. Postmortem neuroanatomical studies, thorough clinical characterization, pathophysiological assessment, and extensive genetic inquiry have failed to identify a cause attributable to a traditional genetic basis, somatic mosaicism, epigenetic mechanism, environmental trigger, or other. To find the key to the ROHHAD pathogenesis and to improve its clinical management, in the present chapter, we have carefully compared CCHS and ROHHAD.

Case Report: COVID-19-Associated ROHHAD-Like Syndrome

It is known that the SARS-CoV-2 virus may cause neurologic damage. Rapid-onset obesity, hypoventilation, hypothalamus dysfunction, and autonomic dysregulation (ROHHAD) syndrome is a disease of unknown etiology with a progressive course and unclear outcomes. The etiology of ROHHAD syndrome includes genetic, epigenetic, paraneoplastic, and immune-mediated theories, but to our knowledge, viral-associated cases of the disease have not been described yet. Here we present the case of a 4-year-old girl who developed a ROHHAD syndrome-like phenotype after a COVID-19 infection and the results of 5 months of therapy. She had COVID-19 pneumonia, followed by electrolyte disturbances (hypernatremia and hyperchloremia), hypocorticism and hypothyroidism, central hypoventilation-requiring prolonged assisted lung ventilation-bulimia, and progressive obesity with hypertriglyceridemia, dyslipidemia, hyperuricemia, and hyperinsulinemia. The repeated MRI of the brain and hypothalamic-pituitary region with contrast enhancement showed mild post-hypoxic changes. Prader-Willi/Angelman syndrome as well as PHOX2B-associated variants was ruled out. Treatment with non-steroidal anti-inflammatory drugs and monthly courses of intravenous immunoglobulin led to a dramatic improvement. Herein the first description of ROHHAD-like syndrome is timely associated with a previous COVID-19 infection with possible primarily viral or immune-mediated hypothalamic involvement.

The Genetics of Sleep Disorders in Children: A Narrative Review

Sleep is a universal, highly preserved process, essential for human and animal life, whose complete functions are yet to be unravelled. Familial recurrence is acknowledged for some sleep disorders, but definite data are lacking for many of them. Genetic studies on sleep disorders have progressed from twin and family studies to candidate gene approaches to culminate in genome-wide association studies (GWAS). Several works disclosed that sleep-wake characteristics, in addition to electroencephalographic (EEG) sleep patterns, have a certain degree of heritability. Notwithstanding, it is rare for sleep disorders to be attributed to single gene defects because of the complexity of the brain network/pathways involved. Besides, the advancing insights in epigenetic gene-environment interactions add further complexity to understanding the genetic control of sleep and its disorders. This narrative review explores the current genetic knowledge in sleep disorders in children, following the International Classification of Sleep Disorders-Third Edition (ICSD-3) categorisation.

A Case Report of ROHHAD Syndrome in an 8-year-old Iranian Boy

INTRODUCTION

Rapid-onset obesity concurrently with hypoventilation, hypothalamic, autonomic dysregulation (ROHHAD) is an uncommon disease that presents with multiorgan disorders during early childhood, with fewer than 100 cases reported around the world. We aim to present a case of ROHHAD syndrome admitting with rare neurologic symptoms. We also present our treatment regimen.

CASE PRESENTATION

An 8-year-old boy was admitted to our department with ataxia and gait disturbance that led us to the final diagnosis after a thorough investigation. He had multiple admissions and was treated for other diagnoses. His first symptoms started from age 5 with obstructive apnea. He underwent an adenectomy surgery at that time, but the symptoms continued. A year after the surgery, he was admitted again due to his somnolence but was diagnosed only with hypothyroidism and anemia. At the age of 7 years and 8 months, he was admitted to our department with ataxia and abnormal gait from the past year with instability and numerous falls. He also had shown hyperphagia that had been resulted in 10 kilograms of weight gain in six months. He was experiencing gradual behavioral symptoms, including episodes of self and hetero aggression and impulsivity. His other symptoms included fatigue, somnolence, gastrointestinal dysmotility, hyperhidrosis, central hypothyroidism, polyuria, precocious puberty, and rapid obesity. His laboratory investigation revealed hyperprolactinemia.

CONCLUSIONS

Our case indicates that ROHHAD is a complex disease with divergent signs and symptoms that needs to be kept in mind for diagnosis and should be treated with a high level of collaboration of various medical specialties. Since late diagnosis of this syndrome leads to a magnificent increase in morbidity and mortality rates, it is vital to pay extreme attention to this syndrome. The diagnosis should be considered even more in children over two years old with rapid-onset obesity, which is accompanied by other symptoms. Here, our patient's complaint was ataxia that revealed the underlying cause after investigation.

ROHHAD (Rapid-onset Obesity with Hypoventilation, Hypothalamic Dysfunction, Autonomic Dysregulation) Syndrome-What Every Pediatrician Should Know About the Etiopathogenesis, Diagnosis and Treatment: A Review

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, autonomic dysregulation (ROHHAD) syndrome is a rare disease with unknown and debated etiology, characterized by precipitous obesity in young children, hypoventilation and autonomic dysregulation with various endocrine abnormalities. Neuroendocrine tumors can be associated in more than half of the cases. This rare condition has a severe outcome because of high morbidity and mortality. We provide a comprehensive description of the etiopathogenetic theories of the disease, clinical presentation, diagnostic workup and treatment possibilities.

ROHHAD(NET) Syndrome: Systematic Review of the Clinical Timeline and Recommendations for Diagnosis and Prognosis

CONTEXT

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation and neural crest tumor (ROHHHAD[NET]) is a rare and potentially fatal disease. No specific diagnostic biomarker is currently available, making prompt diagnosis challenging. Since its first definition in 2007, a complete clinical analysis leading to specific diagnosis and follow-up recommendations is still missing.

OBJECTIVE

The purpose of this work is to describe the clinical timeline of symptoms of ROHHAD(NET) and propose recommendations for diagnosis and follow-up.

DESIGN

We conducted a systematic review of all ROHHAD(NET) case studies and report a new ROHHAD patient with early diagnosis and multidisciplinary care.

METHODS

All the articles that meet the definition of ROHHAD(NET) and provide chronological clinical data were reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis individual patient data guidelines. The data were grouped into 7 categories: hypothalamic dysfunction, autonomic dysregulation, hypoventilation, NET, psychiatric symptoms, other clinical manifestations, and outcome.

RESULTS

Forty-three individual patient data descriptions were analyzed. The timeline of the disease shows rapid-onset obesity followed shortly by hypothalamic dysfunction. Dysautonomia was reported at a median age of 4.95 years and hypoventilation at 5.33 years, or 2.2 years after the initial obesity. A NET was reported in 56% of the patients, and 70% of these tumors were diagnosed within 2 years after initial weight gain.

CONCLUSION

Because early diagnosis improves the clinical management and the prognosis in ROHHAD(NET), this diagnosis should be considered for any child with rapid and early obesity. We propose guidance for systematic follow-up and advise multidisciplinary management with the aim of improving prognosis and life expectancy.

Natural history of ROHHAD syndrome: development of severe insulin resistance and fatty liver disease over time

Background

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare syndrome with unknown etiology. Metabolic abnormalities are not known to be part of the syndrome. We present one of the oldest cases reported in the literature, who developed severe metabolic abnormalities and hepatic disease suggesting that these features may be part of the syndrome.

Case presentation

A 27-year-old woman, diagnosed with ROHHAD syndrome at age 15, who previously developed diabetes insipidus, growth hormone deficiency, hyperprolactinemia, and hypothyroidism in her first decade of life. This was followed by insulin resistance, NAFLD, liver fibrosis, and splenomegaly before age 14 years. Her regimen included a short course of growth hormone, and cyclic estrogen and progesterone. Her metabolic deterioration continued despite treatment with metformin. Interestingly, she had a favorable response to liraglutide therapy despite having a centrally mediated cause for her obesity. At age 26, a 1.6 cm lesion was found incidentally in her liver. Liver biopsy showed hepatocellular carcinoma which was successfully treated with radiofrequency ablation.

Conclusion

Metabolic abnormalities, Insulin resistance and fatty liver disease are potentially part of the ROHHAD syndrome that may develop over time. GLP1 agonists were reasonably effective to treat insulin resistance and hyperphagia. Patients with ROHHAD may benefit from close follow up in regards to liver disease.

Electronic supplementary material

The online version of this article (10.1186/s40842-019-0082-y) contains supplementary material, which is available to authorized users.

Rapid-Onset Obesity with Hypoventilation, Hypothalamic, Autonomic Dysregulation, and Neuroendocrine Tumors (ROHHADNET) Syndrome: A Systematic Review

BACKGROUND AND AIM

ROHHADNET (rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, neuroendocrine tumor) syndrome is a rare disease with grave outcome. Although early recognition is essential, prompt diagnosis may be challenging due to its extreme rarity. This study aimed to systematically review its clinical manifestation and to identify genetic causes.

MATERIALS AND METHODS

We firstly conducted a systematic review on ROHHAD/NET. Electronic databases were searched using related terms. We secondly performed whole exome sequencing (WES) and examined copy number variation (CNV) in two patients to identify genetic causes.

RESULTS

In total, 46 eligible studies including 158 patients were included. There were 36 case reports available for individual patient data (IPD; 48 patients, 23 ROHHAD, and 25 ROHHADNET) and 10 case series available for aggregate patient data (APD; 110 patients, 71 ROHHAD, and 39 ROHHADNET). The median age at onset calculated from IPD was 4 years. Gender information was available in 100 patients (40 from IPD and 60 from APD) in which 65 females and 35 males were showing female preponderance. Earliest manifestation was rapid obesity, followed by hypothalamic symptoms. Most common types of neuroendocrine tumors were ganglioneuromas. Patients frequently had dysnatremia and hyperprolactinemia. Two patients were available for WES. Rare variants were identified in PIK3R3, SPTBN5, and PCF11 in one patient and SRMS, ZNF83, and KMT2B in another patient, respectively. However, there was no surviving variant shared by the two patients after filtering.

CONCLUSIONS

This study systematically reviewed the phenotype of ROHHAD/NET aiming to help early recognition and reducing morbidity. The link of variants identified in the present WES requires further investigation.

Anesthesia in a pediatric patient with ROHADD syndrome

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome is a rare entity that is characterised by its onset in healthy children at 2-4 years of age. It is a complex syndrome that includes, among other symptoms, rapid weight gain with hyperphagia, hypothalamic dysfunction, central hypoventilation, and autonomic dysregulation. The case is presented of a 10-year-old boy with a diagnosis of ROHHAD syndrome undergoing insertion of a port-a-cath under general anaesthesia, who developed complications during the anaesthetic procedure related to his illness. The peri-operative management of these patients represents a challenge for the anaesthetist, given the involvement of multiple systems and the frequent respiratory comorbidities associated with them. A summary is presented of some of the implications and anaesthetic considerations that must be taken into account in the management of these patients.

A systematic review of genetic syndromes with obesity

Syndromic monogenic obesity typically follows Mendelian patterns of inheritance and involves the co-presentation of other characteristics, such as mental retardation, dysmorphic features and organ-specific abnormalities. Previous reviews on obesity have reported 20 to 30 syndromes but no systematic review has yet been conducted on syndromic obesity. We searched seven databases using terms such as 'obesity', 'syndrome' and 'gene' to conduct a systematic review of literature on syndromic obesity. Our literature search identified 13,719 references. After abstract and full-text review, 119 relevant papers were eligible, and 42 papers were identified through additional searches. Our analysis of these 161 papers found that 79 obesity syndromes have been reported in literature. Of the 79 syndromes, 19 have been fully genetically elucidated, 11 have been partially elucidated, 27 have been mapped to a chromosomal region and for the remaining 22, neither the gene(s) nor the chromosomal location(s) have yet been identified. Interestingly, 54.4% of the syndromes have not been assigned a name, whereas 13.9% have more than one name. We report on organizational inconsistencies (e.g. naming discrepancies and syndrome classification) and provide suggestions for improvements. Overall, this review illustrates the need for increased clinical and genetic research on syndromes with obesity.

Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, autonomic dysregulation and neuroendocrine tumor syndrome with a homogenous enlargement of the pituitary gland: a case report

Background

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome is a rare pediatric disorder with a variable sequence of clinical presentations, undefined etiology, and high risk of mortality. Our patient presented an unusual course of the disease accompanied by a homogenous mild enlargement of her pituitary gland with an intact pituitary–endocrine axis which, to the best of our knowledge, represents a new finding in rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome.

Case presentation

We present a documented case of a 4 years and 8-month-old Syrian Arabic girl with a distinctive course of signs and symptoms of rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome accompanied by mature ganglioneuroma in her chest, a homogenous mild enlargement of her pituitary gland, generalized cortical brain atrophy, and seizures. Three months after her first marked symptoms were noted she had a sudden progression of severe respiratory distress that ended with her death.

Conclusions

The findings of this case could increase our understanding of the pathogenetic mechanisms of rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation, and place more emphases on pediatricians to consider rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome whenever early rapid onset of obesity, associated with any malfunction, is observed in children. This knowledge could be lifesaving for children with rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome.

Improved Behavior and Neuropsychological Function in Children With ROHHAD After High-Dose Cyclophosphamide

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare, generally progressive, and potentially fatal syndrome of unclear etiology. The syndrome is characterized by normal development followed by a sudden, rapid hyperphagic weight gain beginning during the preschool period, hypothalamic dysfunction, and central hypoventilation, and is often accompanied by personality changes and developmental regression, leading to substantial morbidity and mortality. We describe 2 children who had symptomatic and neuropsychological improvement after high-dose cyclophosphamide treatment. Our experience supports an autoimmune pathogenesis and provides the first neuropsychological profile of patients with rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation.

Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD syndrome): A case report and literature review

INTRODUCTION

ROHHAD syndrome (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) is a rare and complex disease, presenting in previously healthy children at the age of 2-4 years. Up to 40% of cases are associated with neural crest tumours.

DEVELOPMENT

We present the case of a 2-year-old girl with symptoms of rapidly progressing obesity, who a few months later developed hypothalamic dysfunction with severe electrolyte imbalance, behaviour disorder, hypoventilation, and severe autonomic dysregulation, among other symptoms. Although the pathophysiology of this syndrome remains unclear, an autoimmune hypothesis has been proposed for ROHHAD. Therefore, after obtaining a limited response to intravenous immunoglobulins, we decided to test the response to a high dose cyclophosphamide (low dose was not effective either). Unfortunately our patient experienced many severe complications (among them central pontine myelinolysis, from which the patient recovered, and failure to wean from the ventilator requiring tracheostomy and long term ventilation) that required a prolonged ICU stay. Although her behaviour improved, our patient unfortunately died suddenly at home at the age of 5 due to respiratory pathology.

CONCLUSIONS

ROHHAD syndrome is a rare and little-known disease which requires a multidisciplinary approach because it involves complex symptoms and multiple organ system involvement. Alveolar hypoventilation should be identified early and appropriate treatment should be started promptly for the best possible outcome. Immunomodulatory treatment with immunoglobulins, cyclophosphamide, or rituximab has previously resulted in symptom improvement in some cases. Because of the low incidence of the syndrome, multi-centre studies must be carried out in order to gather more accurate information about ROHHAD pathophysiology and design an appropriate therapeutic approach.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): Response to ventilatory challenges

Hypoventilation is a defining feature of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), a rare respiratory and autonomic disorder. This chronic hypoventilation has been explained as the result of dysfunctional chemosensory control circuits, possibly affecting peripheral afferent input, central integration, or efferent motor control. However, chemosensory function has never been quantified in a cohort of ROHHAD patients. Therefore, the purpose of this study was to assess the response to awake ventilatory challenge testing in children and adolescents with ROHHAD. The ventilatory, cardiovascular and cerebrovascular responses in 25 distinct comprehensive physiological recordings from seven unique ROHHAD patients to three different gas mixtures were analyzed at breath-to-breath and beat-to-beat resolution as absolute measures, as change from baseline, or with derived metrics. Physiologic measures were recorded during a 3-min baseline period of room air, a 3-min gas exposure (of 100% O2; 95% O2, 5% CO2; or 14% O2, 7% CO2 balanced with N2), and a 3-min recovery period. An additional hypoxic challenge was conducted which consisted of either five or seven tidal breaths of 100% N2. While ROHHAD cases showed a diminished VT and inspiratory drive response to hypoxic hypercapnia and absent behavioral awareness of the physiologic compromise, most ventilatory, cardiovascular, and cerebrovascular measures were similar to those of previously published controls using an identical protocol, suggesting a mild chemosensory deficit. Nonetheless, the high mortality rate, comorbidity and physiological fragility of patients with ROHHAD demand continued clinical vigilance.

Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD): exome sequencing of trios, monozygotic twins and tumours

BACKGROUND

Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) is thought to be a genetic disease caused by de novo mutations, though causative mutations have yet to be identified. We searched for de novo coding mutations among a carefully-diagnosed and clinically homogeneous cohort of 35 ROHHAD patients.

METHODS

We sequenced the exomes of seven ROHHAD trios, plus tumours from four of these patients and the unaffected monozygotic (MZ) twin of one (discovery cohort), to identify constitutional and somatic de novo sequence variants. We further analyzed this exome data to search for candidate genes under autosomal dominant and recessive models, and to identify structural variations. Candidate genes were tested by exome or Sanger sequencing in a replication cohort of 28 ROHHAD singletons.

RESULTS

The analysis of the trio-based exomes found 13 de novo variants. However, no two patients had de novo variants in the same gene, and additional patient exomes and mutation analysis in the replication cohort did not provide strong genetic evidence to implicate any of these sequence variants in ROHHAD. Somatic comparisons revealed no coding differences between any blood and tumour samples, or between the two discordant MZ twins. Neither autosomal dominant nor recessive analysis yielded candidate genes for ROHHAD, and we did not identify any potentially causative structural variations.

CONCLUSIONS

Clinical exome sequencing is highly unlikely to be a useful diagnostic test in patients with true ROHHAD. As ROHHAD has a high risk for fatality if not properly managed, it remains imperative to expand the search for non-exomic genetic risk factors, as well as to investigate other possible mechanisms of disease. In so doing, we will be able to confirm objectively the ROHHAD diagnosis and to contribute to our understanding of obesity, respiratory control, hypothalamic function, and autonomic regulation.

Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, autonomic dysregulation syndrome

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction and autonomic dysregulation syndrome is a rare disorder that presents with rapidly evolving obesity with several endocrine disorders during early childhood. We present here a documented case of a 6-year-old Syrian girl with the characteristic symptoms of rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation, associated with an abdominal mass (mature ganglioneuroma).

ROHHAD Syndrome: Reasons for Diagnostic Difficulties in Obesity

A very rare syndrome of rapid-onset obesity with hypoventilation, hypothalamic dysfunction and autonomic dysregulation (ROHHAD) has been recently described as causing morbidity due to hypothalamic dysfunction and respiratory arrest. Its prognosis is poor and often cardiac arrest occurs due to alveolar hypoventilation. This disorder can mimic genetic obesity syndromes and several endocrine disorders. We present a 13-year-old female patient who was reported to be healthy until the age of 3 years. She was admitted to our emergency department, presenting with respiratory distress. Features matching ROHHAD syndrome such as rapid-onset obesity, alveolar hypoventilation, central hypothyroidism, hyperprolactinemia, Raynaud phenomenon and hypothalamic hypernatremia were detected in the patient. In addition to these features, the patient was found to have hypergonadotropic hypogonadism and megaloblastic anemia. Because of its high mortality and morbidity, the possibility of ROHHAD syndrome needs to be considered in all pediatric cases of early- and rapid-onset obesity associated with hypothalamic-pituitary endocrine dysfunction.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation: review and update

PURPOSE OF REVIEW

The focus of this review is to compare and contrast two orphan disorders of late-onset hypoventilation. Specifically, rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) and congenital central hypoventilation syndrome (CCHS) are distinct in presentation, pathophysiology, and etiology.

RECENT FINDINGS

While limited new information is available, appreciation and understanding of rare disorders can be attained through case reports. Recent literature in ROHHAD has included case reports with new findings that may provide insight into pathophysiology involving possible aberrant immune process and dysregulation at the level of the orexinergic system.

SUMMARY

The etiology of ROHHAD continues to be elusive. The hope is that, with growing recognition, discussion, and investigation into the overlap of ROHHAD with disorders outside congenital central hypoventilation syndrome, further advancement will be made.

Hypocretin-1 deficiency in a girl with ROHHAD syndrome

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare and complex pediatric syndrome, essentially caused by dysfunction of 3 vital systems regulating endocrine, respiratory, and autonomic nervous system functioning. The clinical spectrum of ROHHAD is broad, but sleep/wake disorders have received relatively little attention so far, although the central hypothalamic dysfunction would make the occurrence of sleep symptoms likely. In this case report, we expand the phenotype of ROHHAD with a number of striking sleep symptoms that together can be classified as a secondary form of narcolepsy. We present a 7-year-old girl with ROHHAD who displayed the classic features of narcolepsy with cataplexy: excessive daytime sleepiness with daytime naps, visual hallucinations, and partial cataplexy reflected in intermittent loss of facial muscle tone. Nocturnal polysomnography revealed sleep fragmentation and a sleep-onset REM period characteristic for narcolepsy. The diagnosis was confirmed by showing an absence of hypocretin-1 in the cerebrospinal fluid. We discuss potential pathophysiological implications as well as symptomatic treatment options.

Congenital central hypoventilation syndrome and sudden infant death syndrome: disorders of autonomic regulation

Long considered a rare and unique disorder of respiratory control, congenital central hypoventilation syndrome has recently been further distinguished as a disorder of autonomic regulation. Similarly, more recent evidence suggests that sudden infant death syndrome is also a disorder of autonomic regulation. Congenital central hypoventilation syndrome typically presents in the newborn period with alveolar hypoventilation, symptoms of autonomic dysregulation and, in a subset of cases, Hirschsprung disease or tumors of neural crest origin or both. Genetic investigation identified PHOX2B, a crucial gene during early autonomic development, as disease defining for congenital central hypoventilation syndrome. Although sudden infant death syndrome is most likely defined by complex multifactorial genetic and environmental interactions, it is also thought to result from central deficits in the control of breathing and autonomic regulation. The purpose of this article is to review the current understanding of these autonomic disorders and discuss the influence of this information on clinical practice and future research directions.

Anesthetic considerations for rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction (ROHHAD) syndrome in children

Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction is an increasingly common diagnosis in patients who are being seen at tertiary care children's hospitals. We present two cases of anesthetics from the authors' own experience in addition to a comprehensive review of the disorder and anesthetic implications.

Genetic testing in patients with obesity

The obesity epidemic is associated with the recent availability of highly palatable and inexpensive caloric food as well as important changes in lifestyle. Genetic factors, however, play a key role in regulating energy balance and numerous twin studies have estimated the BMI heritability between 40 and 70%. While common variants, identified through genome-wide association studies (GWAS) point toward new pathways, their effect size are too low to be of any use in the clinic. This review therefore concentrates on genes and genomic regions associated with very high risks of human obesity. Although there are no consensus guidelines, we review how the knowledge on these "causal factors" can be translated into the clinic for diagnostic purposes. We propose genetic workups guided by clinical manifestations in patients with severe early-onset obesity. While etiological diagnoses are unequivocal in a minority of patients, new genomic tools such as Comparative Genomic Hybridization (CGH) array, have allowed the identification of novel "causal" loci and next-generation sequencing brings the promise of accelerated pace for discoveries relevant to clinical practice.