Central Hypoventilation Syndrome Research Articles

Tracheostomy and inpatient outcomes among children with congenital central hypoventilation syndrome: A kids' inpatient database study

Tracheostomy and inpatient outcomes among children with congenital central hypoventilation syndrome: A kids' inpatient database study

Clinical and Genetic Correlation in Neurocristopathies: Bridging a Precision Medicine Gap.

Neurocristopathies (NCPs) encompass a spectrum of disorders arising from issues during the formation and migration of neural crest cells (NCCs). NCCs undergo epithelial-mesenchymal transition (EMT) and upon key developmental gene deregulation, fetuses and neonates are prone to exhibit diverse manifestations depending on the affected area. These conditions are generally rare and often have a genetic basis, with many following Mendelian inheritance patterns, thus making them perfect candidates for precision medicine. Examples include cranial NCPs, like Goldenhar syndrome and Axenfeld-Rieger syndrome; cardiac-vagal NCPs, such as DiGeorge syndrome; truncal NCPs, like congenital central hypoventilation syndrome and Waardenburg syndrome; and enteric NCPs, such as Hirschsprung disease. Additionally, NCCs' migratory and differentiating nature makes their derivatives prone to tumors, with various cancer types categorized based on their NCC origin. Representative examples include schwannomas and pheochromocytomas. This review summarizes current knowledge of diseases arising from defects in NCCs' specification and highlights the potential of precision medicine to remedy a clinical phenotype by targeting the genotype, particularly important given that those affected are primarily infants and young children.

The Influence of Neurotrophins on the Brain-Lung Axis: Conception, Pregnancy, and Neonatal Period.

Neurotrophins (NTs) are four small proteins produced by both neuronal and non-neuronal cells; they include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). NTs can exert their action through both genomic and non-genomic mechanisms by interacting with specific receptors. Initial studies on NTs have identified them only as functional molecules of the nervous system. However, recent research have shown that some tissues and organs (such as the lungs, skin, and skeletal and smooth muscle) as well as some structural cells can secrete and respond to NTs. In addition, NTs perform several roles in normal and pathological conditions at different anatomical sites, in both fetal and postnatal life. During pregnancy, NTs are produced by the mother, placenta, and fetus. They play a pivotal role in the pre-implantation process and in placental and embryonic development; they are also involved in the development of the brain and respiratory system. In the postnatal period, it appears that NTs are associated with some diseases, such as sudden infant death syndrome (SIDS), asthma, congenital central hypoventilation syndrome (CCHS), and bronchopulmonary dysplasia (BPD).

Recurrence of CCHS-associated PHOX2B Poly-Alanine expansion variant due to paternal mosaicism

BackgroundPaired-like Homeobox 2B (PHOX2B) is considered the causative gene of Congenital Central Hypoventilation Syndrome (CCHS), a dominant genetic disorder characterized by impaired central respiratory control and subsequent hypoventilation during sleep. MethodsHerein, we present a family with recurrent severe CCHS. The potential causative genetic variant was confirmed through Whole-Exome Sequencing (WES), Sanger sequencing, and droplet digital PCR (ddPCR). Furthermore, prenatal diagnosis was performed on the proband's mother at 20 weeks of her fourth pregnancy upon request. ResultsThe proband and her brother were both carriers of the PHOX2B polyalanine expansion variant: c.744_758dupCGCGGCAGCGGCGGCGGCGGC. Sanger sequencing revealed that the proband's father had a small variant peak in the gene position, implying potential somatic mosaicism. In addition, ddPCR results showed that the proband's father had germline mosaicism, with a mosaicism proportion of 14.3%. Notably, the detect p.(Ala241[26]) variant was not detected in the fetus. ConclusionsThese findings have important implications for improving genetic counseling of CCHS families as they suggest that even parents without CCHS symptoms may have somatic chimerism, necessitating careful genetic counseling and consideration of prenatal testing for subsequent pregnancies.

Congenital central hypoventilation syndrome: A rare disorder in a neonate

No abstract available

Alternative low-populated conformations prompt phase transitions in polyalanine repeat expansions

Abnormal trinucleotide repeat expansions alter protein conformation causing malfunction and contribute to a significant number of incurable human diseases. Scarce structural insights available on disease-related homorepeat expansions hinder the design of effective therapeutics. Here, we present the dynamic structure of human PHOX2B C-terminal fragment, which contains the longest polyalanine segment known in mammals. The major α-helical conformation of the polyalanine tract is solely extended by polyalanine expansions in PHOX2B, which are responsible for most congenital central hypoventilation syndrome cases. However, polyalanine expansions in PHOX2B additionally promote nascent homorepeat conformations that trigger length-dependent phase transitions into solid condensates that capture wild-type PHOX2B. Remarkably, HSP70 and HSP90 chaperones specifically seize PHOX2B alternative conformations preventing phase transitions. The precise observation of emerging polymorphs in expanded PHOX2B postulates unbalanced phase transitions as distinct pathophysiological mechanisms in homorepeat expansion diseases, paving the way towards the search of therapeutics modulating biomolecular condensates in central hypoventilation syndrome.

An unusual ophthalmologic finding in a patient with congenital central hypoventilation syndrome.

Congenital Central Hypoventilation Syndrome (CCHS) is a rare disease due to a severely impaired central control of breathing and dysfunction of the autonomic nervous system. Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. We report a unique case of CCHS in association with monocular elevation deficit (MED) in a boy diagnosed with CCHS at birth. We report a case of a boy with a confirmed diagnosis of CCHS (complete sequencing of the paired-like homeobox 2b (PHOX2B) gene) after presenting little respiratory effort and cyanosis at birth. The ophthalmological examination shows an impaired elevation of the left eye, both in adduction and abduction, associated with mild and variable left ptosis. His mother has observed that the left eyelid elevates when the child feeds. A deviation in the primary gaze position or a chin-up position are not present. The funduscopic examination is normal. Given that deviation is limited to upgaze, the ptosis is mild and the patient's age, observation is decided. Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. To the best of our knowledge, this is the first report of MED in association with CCHS. Further studies are needed to determine if an association between MED and CCHS exists or is just a casual finding in this case.

Delineation of ADPRHL2 Variants: Report of Two New Patients with Review of the Literature.

ADPRHL2 is involved in posttranslational modification and is known to have a role in physiological functions such as cell signaling, DNA repair, gene control, cell death, and response to stress. Recently, a group of neurological disorders due to ADPRHL2 variants is described, characterized by childhood-onset, stress-induced variable movement disorders, neuropathy, seizures, and neurodegenerative course. We present the diagnostic pathway of two pediatric patients with episodic dystonia and ataxia, who later had a neurodegenerative course complicated by central hypoventilation syndrome due to the same homozygous ADPRHL2 variant. We conducted a systematic literature search and data extraction procedure following the Preferred Reporting Items for Systematic Review and Meta-Analysis 2020 statement in terms of patients with ADPRHL2 variants, from 2018 up to 3 February, 2023. In total, 12 articles describing 47 patients were included in the final analysis. Median age at symptom onset was 2 (0.7-25) years, with the most common presenting symptoms being gait problems (n = 19, 40.4%), seizures (n = 16, 34%), ataxia (n = 13, 27.6%), and weakness (n = 10, 21.2%). Triggering factors (28/47; 59.5%) and regression (28/43; 60.4%), axonal polyneuropathy (9/23; 39.1%), and cerebral and cerebellar atrophy with white matter changes (28/36; 77.7%) were the other clues. The fatality rate and median age of death were 44.6% (n = 21) and 7 (2-34) years, respectively. ADPRHL2 variants should be considered in the context of episodic, stress-induced pediatric and adult-onset movement disorders and seizures.

Monitoring of physiologic features and treatment aspects of children on home invasive mechanical ventilation.

Pediatric home invasive mechanical ventilation patients are a small but resource-intensive cohort, requiring close monitoring and multidisciplinary care. Patients are often dependent on their ventilator for life support, with any significant complications such as equipment failure, tracheostomy blockage, or accidental decannulation becoming potentially life-threatening if not identified quickly. This review discusses the indications and variations in practice worldwide, in terms of models of care, including home care provision, choice of equipment, and monitoring. With advances in technology, optimal monitoring strategies for home, continue to be debated: In-built ventilator alarms are often inadequately sensitive for pediatric patients, necessitating additional external monitoring devices to minimize risk. Pulse oximetry has been the preferred monitoring modality at home, though in some special circumstances such as congenital central hypoventilation syndrome, home carbon dioxide monitoring may be important to consider. Children should be under regular follow-up at specialist respiratory centers where clinical evaluation, nocturnal oximetry, and capnography monitoring and/or poly(somno)graphy and analysis of ventilator download data can be performed regularly to monitor progress. Recent exciting advances in technology, particularly in telemonitoring, which have potential to hugely benefit this complex group of patients are also discussed.

Revolutionizing congenital central hypoventilation syndrome screening: the potential of machine learning approaches

Revolutionizing congenital central hypoventilation syndrome screening: the potential of machine learning approaches

Defective exercise-related expiratory muscle recruitment in patients with PHOX2B mutations: A clue to neural determinants of the congenital central hypoventilation syndrome

Introduction and objectivesThe human congenital central hypoventilation syndrome (CCHS) is caused by mutations in the PHOX2B (paired-like homeobox 2B) gene. Genetically engineered PHOX2B rodents exhibit defective development of the brainstem retrotrapezoid nucleus (RTN), a carbon dioxide sensitive structure that critically controls expiratory muscle recruitment. This has been linked to a blunted exercise ventilatory response. Whether this can be extrapolated to human CCHS is unknown and represents the objective of this study. Materials and methodsThirteen adult CCHS patients and 13 healthy participants performed an incremental symptom-limited cycle cardiopulmonary exercise test. Responses were analyzed using guideline approaches (ventilation V'E, tidal volume VT, breathing frequency, oxygen consumption, carbon dioxide production) complemented by a breathing pattern analysis (i.e. expiratory and inspiratory reserve volume, ERV and IRV). ResultsA ventilatory response occurred in both study groups, as follows: V'E and VT increased in CCHS patients until 40 W and then decreased, which was not observed in the healthy participants (p<0.001). In the latter, exercise-related ERV and IRV decreases attested to concomitant expiratory and inspiratory recruitment. In the CCHS patients, inspiratory recruitment occurred but there was no evidence of expiratory recruitment (absence of any ERV decrease, p<0.001). ConclusionsAssuming a similar organization of respiratory rhythmogenesis in humans and rodents, the lack of exercise-related expiratory recruitment observed in our CCHS patients is compatible with a PHOX2B-related defect of a neural structure that would be analogous to the rodents' RTN. Provided corroboration, ERV recruitment could serve as a physiological outcome in studies aiming at correcting breathing control in CCHS.

Diagnosis and treatment of later onset congenital central hypoventilation syndrome in children

Diagnosis and treatment of later onset congenital central hypoventilation syndrome in children

Computer-aided diagnostic screen for Congenital Central Hypoventilation Syndrome with facial phenotype.

Congenital Central Hypoventilation Syndrome (CCHS) has devastating consequences if not diagnosed promptly. Despite identification of the disease-defining gene PHOX2B and a facial phenotype, CCHS remains underdiagnosed. This study aimed to incorporate automated techniques on facial photos to screen for CCHS in a diverse pediatric cohort to improve early case identification and assess a facial phenotype-PHOX2B genotype relationship. Facial photos of children and young adults with CCHS were control-matched by age, sex, race/ethnicity. After validating landmarks, principal component analysis (PCA) was applied with logistic regression (LR) for feature attribution and machine learning models for subject classification and assessment by PHOX2B pathovariant. Gradient-based feature attribution confirmed a subtle facial phenotype and models were successful in classifying CCHS: neural network performed best (median sensitivity 90% (IQR84%, 95%)) on 179 clinical photos (versus LR and XGBoost, both 85% (IQR75-76%, 90%)). Outcomes were comparable stratified by PHOX2B genotype and with the addition of publicly available CCHS photos (n = 104) using PCA and LR (sensitivity 83-89% (IQR67-76%, 92-100%). Utilizing facial features, findings suggest an automated, accessible classifier may be used to screen for CCHS in children with the phenotype and support providers to seek PHOX2B testing to improve the diagnostics. Facial landmarking and principal component analysis on a diverse pediatric and young adult cohort with PHOX2B pathovariants delineated a distinct, subtle CCHS facial phenotype. Automated, low-cost machine learning models can detect a CCHS facial phenotype with a high sensitivity in screening to ultimately refer for disease-defining PHOX2B testing, potentially addressing gaps in disease underdiagnosis and allow for critical, timely intervention.

Diaphragmatic pacing for respiratory failure in children

Diaphragm pacing is a ventilation strategy in respiratory failure. Most of the literature on pacing involves adults with common indications being spinal cord injury and amyotrophic lateral sclerosis (ALS). Previous reports in pediatric patients consist of case reports or small series; most describe direct phrenic nerve stimulation for central hypoventilation syndrome. This differs from adult reports that focus most commonly on spinal cord injuries and the rehabilitative nature of diaphragm pacing. This review describes the current state of diaphragm pacing in pediatric patients. Indications, current available technologies, surgical techniques, advantages, and pitfalls/problems are discussed.

[Research advances on late-onset congenital central hypoventilation syndrome].

[Research advances on late-onset congenital central hypoventilation syndrome].

A rare case of congenital central hypoventilation syndrome in a premature neonate with multiple coexisting morbidities: A comprehensive clinical analysis

A rare case of congenital central hypoventilation syndrome in a premature neonate with multiple coexisting morbidities: A comprehensive clinical analysis

Elevated transaminases in congenital central hypoventilation syndrome.

Patients with CCHS who also have Hirschsprung disease, elevated or low BMI, or pulmonary hypertension may be predisposed to elevated transaminases and may need periodic follow-up of their hepatic function https://bit.ly/3uW7AUG.

Characteristics and outcomes in children with congenital central hypoventilation syndrome on long-term mechanical ventilation in the Netherlands.

Our study results suggest that in our cohort, the genotype is not easily associated to the phenotype in CCHS. Consistent with these findings and international literature, we recommend a thorough annual evaluation for all patients with CCHS to ensure optimal management and follow-up. • The majority of CCHS patients are dependent on ventilatory support. • Variants in the PHOX2B gene are responsible for the characteristics of CCHS. • This study provides insight into the clinical course and long-term outcomes of CCHS patients in the Netherlands. • In CCHS, the genotype is not easily associated with the phenotype, requiring a thorough life-long follow-up for all patients.

KONJENİTAL SANTRAL HİPOVENTİLASYON SENDROMU VE SEREBRAL PALSİLİ OLGUDA FİZYOTERAPİ VE REHABİLİTASYON PROGRAMININ ETKİSİNİN İNCELENMESİ: BİR OLGU SUNUMU

Congenital Central Hypoventilation Syndrome is a rare genetic disorder that presents from birth and prevents automatic control of respiration. Our aim in this study was to examine the effectiveness of a 6-month physical therapy program applied to a patient with Congenital Central Hypoventilation Syndrome and cerebral palsy. A 6-month-old patient who was diagnosed with Congenital Central Hypoventilation Syndrome and subsequently developed Cerebral Palsy due to asphyxia was included in the study. The case was enrolled in a physical therapy program for 2 days a week for 6 months in the home environment where they lived. The case was evaluated before and after treatment. In our case, the Modified Ashworth Scale, the Alberta Infant Motor Scale, the Hammersmith Infant Neurological Examination, Test of Sensory Functions in Infants, and the Face, Legs, Activity, Cry, Consol ability scale were used. In our case, pre-treatment and post-treatment scores were as follows, respectively: Alberta Infant Motor Scale score 3-8, Hammersmith Infant Neurological Examination score 6-17, Test of Sensory Functions in Infants score 2-9, and Face, Legs, Activity, Cry, Consol ability scale score 8-3. In our case, there was a significant improvement in Modified Ashworth Scale scores before and after treatment. Additionally, at the conclusion of the study, it was noted that the heightened pain and sensitivity resulting from the patient's extended stay in the intensive care unit reduced with the treatment. We believe that the administered physiotherapy and rehabilitation program offered support to the patient in achieving neuro-motor and sensory integration, underscoring the essential role of physiotherapy in rare diseases.

P010 Delivery of volume assured pressure support (VAPS) through tracheostomy in paediatric patients

Abstract INTRODUCTION Volume assured pressure support (VAPS) allows the ventilator to deliver a constant pre-set tidal volume or alveolar ventilation by automatically adjusting the inspiratory pressures within a set range, providing targeted pressure support. Data on its use in children are limited. We describe a series of four children effectively and safely ventilated using VAPS mode through tracheostomy. METHODS Retrospective review of patient notes. PROGRESS TO DATE Four paediatric patients were identified in our cohort who were successfully and safely ventilated using the VAPS mode through tracheostomy. The patients were between 6-14 years of age inclusive, with four differing underlying disease processes – Prader-Willi syndrome, congenital central hypoventilation syndrome, Guillain-Barré syndrome and Moebius-type syndrome. INTENDED OUTCOME AND IMPACT Whilst there have been previous paediatric case reports and case series which have demonstrated efficacy of VAPS mode used non-invasively, the use of VAPS mode to provide effective and safe ventilation through tracheostomy in children has been described in only one recent case series. The advantages of its use over conventional bilevel positive airway pressure support include its ability to compensate for changes in tidal volume, which can occur with changes in lung compliance and during different stages of sleep. This case series highlights safe and effective use of VAPS mode in children with tracheostomy.