CHARGE syndrome

The child who lived: Down syndrome among Neanderthals?

Caregiving for disabled individuals among Neanderthals has been known for a long time, and there is a debate about the implications of this behavior. Some authors believe that caregiving took place between individuals able to reciprocate the favor, while others argue that caregiving was produced by a feeling of compassion related to other highly adaptive prosocial behaviors. The study of children with severe pathologies is particularly interesting, as children have a very limited possibility to reciprocate the assistance. We present the case of a Neanderthal child who suffered from a congenital pathology of the inner ear, probably debilitating, and associated with Down syndrome. This child would have required care for at least 6 years, likely necessitating other group members to assist the mother in childcare.

Prevalence and descriptive epidemiology of choanal atresia and stenosis in Texas, 1999-2018

Choanal atresia and stenosis are common causes of congenital nasal obstruction, but their epidemiology is poorly understood. Compared to bilateral choanal atresia/stenosis, unilateral choanal atresia/stenosis is generally diagnosed later and might be under-ascertained in birth defect registries. Data from the population-based Texas Birth Defects Registry and Texas vital records, 1999-2018, were used to assess the prevalence of choanal atresia/stenosis. Poisson regression models were used to evaluate associations with infant and maternal characteristics in two analytic groups: isolated choanal atresia/stenosis (n = 286) and isolated, bilateral choanal atresia/stenosis (n = 105). The overall prevalence of choanal atresia/stenosis was 0.92/10,000, and the prevalence of isolated choanal atresia/stenosis was 0.37/10,000 livebirths. Variables associated with choanal atresia/stenosis in one or both analytic groups included infant sex, pregnancy plurality, maternal race/ethnicity, maternal age, and maternal residence on the Texas-Mexico border. In general, adjusted prevalence ratios estimated from the two analytic groups were in the same direction but tended to be stronger in the analyses restricted to isolated, bilateral defects. Epidemiologic studies of isolated choanal atresia/stenosis should consider focusing on cases with bilateral defects, and prioritizing analyses of environmental, social, and structural factors that could account for the association with maternal residence on the Texas-Mexico border.

CHD7 regulates craniofacial cartilage development via controlling HTR2B expression

Mutations in the Chromodomain helicase DNA-binding protein 7 - coding gene (CHD7) cause CHARGE syndrome (CS). Although craniofacial and skeletal abnormalities are major features of CS patients, the role of CHD7 in bone and cartilage development remain largely unexplored. Here, using a zebrafish (Danio rerio) CS model, we show that chd7-/- larvae display abnormal craniofacial cartilage development and spinal deformities. The craniofacial and spine defects are accompanied by a marked reduction of bone mineralization. At the molecular level, we show that these phenotypes are associated with significant reduction in the expression levels of osteoblast differentiation markers. Additionally, we detected a marked depletion of collagen 2α1 in the cartilage of craniofacial regions and vertebrae, along with significantly reduced number of chondrocytes. Chondrogenesis defects are at least in part due to downregulation of htr2b, which we found to be also dysregulated in human cells derived from an individual with CHD7 mutation-positive CS. Overall, this study thus unveils an essential role for CHD7 in cartilage and bone development, with potential clinical relevance for the craniofacial defects associated with CS.

The multifaceted links between hearing loss and chronic kidney disease

Hearing loss affects nearly 1.6 billion people and is the third-leading cause of disability worldwide. Chronic kidney disease (CKD) is also a common condition that is associated with adverse clinical outcomes and high health-care costs. From a developmental perspective, the structures responsible for hearing have a common morphogenetic origin with the kidney, and genetic abnormalities that cause familial forms of hearing loss can also lead to kidney disease. On a cellular level, normal kidney and cochlea function both depend on cilial activities at the apical surface, and kidney tubular cells and sensory epithelial cells of the inner ear use similar transport mechanisms to modify luminal fluid. The two organs also share the same collagen IV basement membrane network. Thus, strong developmental and physiological links exist between hearing and kidney function. These theoretical considerations are supported by epidemiological data demonstrating that CKD is associated with a graded and independent excess risk of sensorineural hearing loss. In addition to developmental and physiological links between kidney and cochlear function, hearing loss in patients with CKD may be driven by specific medications or treatments, including haemodialysis. The associations between these two common conditions are not commonly appreciated, yet have important implications for research and clinical practice.

Fetal Phenotype of CHARGE Syndrome with a Molecular Confirmation: A Series of 13 Cases

INTRODUCTION

CHARGE syndrome is an autosomal dominant genetic disorder with known pattern of features. The aim of the study was to present the fetal features of CHARGE syndrome to gain awareness that the antenatal characteristics can be very nonspecific.

CASE PRESENTATION

This was a retrospective study of 13 cases with CHARGE syndrome diagnosed by prenatal or postnatal genetic testing and physical examination. Two (15.4%; 2/13) had normal ultrasound scans during pregnancy. One (7.7%; 1/13) with first-trimester cystic hygroma presented intrauterine fetal demise at 16 weeks gestation. The remaining 10 (76.9%; 10/13) cases had abnormal ultrasound features in utero; among these, 1 had an increased nuchal translucency in the first trimester, 5 had second-trimester abnormal ultrasounds including micrognathia, cardiac defects, and facial defects, and 4 third-trimester abnormal ultrasounds including micrognathia, isolated fetal growth restriction, and polyhydramnios. Among the 11 cases with abnormal prenatal ultrasound scans, no fetus could reach the diagnostic criteria of CHARGE syndrome if only based on the results of ultrasound. However, the diagnosis was made in all cases when CHD7 defects were detected.

DISCUSSION/CONCLUSION

The CHARGE syndrome presents non-specific abnormal ultrasound markers in utero. Exome sequencing in the genetic workup will aid in prenatal diagnosis of this syndrome.

The Incidence and Outcomes for Children with Cleft Palate and/or Lip and CHARGE Syndrome

OBJECTIVES

Published literature on children with cleft palate and/or lip (CP + /-L) and CHARGE syndrome (CS) is limited. This study investigated cleft characteristics including surgery, and feeding and communication outcomes in children identified with CP + /-L and CS.

DESIGN

Retrospective cross-sectional review.

SETTING

Regional Referral Centre for Paediatric Cleft Surgery.

PATIENTS

All children diagnosed with CP + /-L and CS (based on clinical features and/or CHD7 mutation testing) between 1989-2019.

MAIN OUTCOME MEASURES

Cleft type, timing of CP + /-L repair, reasons for 'delayed' repair, feeding methods and communication modality.

RESULTS

Twenty-two children with CP + /-L and CS were identified. Cleft sub-types (%) were: Eleven (50%) had bilateral cleft lip and palate (BCLP), six (27%) had unilateral cleft lip and palate (UCLP) and five (23%) had cleft palate (CP). Cleft repair was delayed compared to protocol care for non-syndromic children with CP + /-L. Median age for lip repair + /- vomerine flap was 9 months (range 4-22 months), and palate repair was 21 months (range 11-40 months). Median age for isolated CP repair was 13 months (range 7-23). Surgery for cardiac anomalies (36%) before cleft repair, and (59%) were classed as having severe systemic disease at the time of cleft surgery. Only 27% of the children in this study had both full oral feeding and verbal communication.

CONCLUSIONS

Children with CP + /-L and CS had severe cleft types and complex medical problems leading to delayed cleft surgery. Feeding and speech outcomes were better in the children aged over ten years.

CHARGE syndrome with early fetal ear abnormalities: A case report

Key Clinical Message

CHARGE syndrome is a rare genetic disorder characterized by several distinct features. The presence of fetal ear abnormalities could be the early indicator of CHARGE syndrome. Subsequent prenatal diagnosis is essential to confirm the disorder. This is significant because the patient may receive genetic counseling and appropriate disposal based on the accurate diagnosis.

Abstract

CHARGE syndrome is a rare genetic disorder with multiple specific clinical features. The prenatal diagnosis is crucial but rarely achieved. We report a fetus with fetal external ear abnormality detected by ultrasound at 22nd week of gestation. Postnatal examination revealed an external ear abnormality, a mild atrial septal defect, and other clinical signs of CHARGE syndrome. A de novo pathogenic nonsense mutation in the CHD7 gene (c.406C > T, p.Q136X in exon 2) was identified to cause the disorder. Our study demonstrated that prenatal diagnosis and genetic testing were recommended to obtain a solid diagnosis of CHARGE syndrome when fetal external ear abnormality was detected by ultrasound examination.

Effects of 4 Testing Arena Sizes and 11 Types of Embryo Media on Sensorimotor Behaviors in Wild-Type and chd7 Mutant Zebrafish Larvae

The larval zebrafish is a highly versatile model across research disciplines, and the expanding use of behavioral analysis has contributed to many advances in neuropsychiatric, developmental, and toxicological studies, often through large-scale chemical and genetic screens. In the absence of standardized approaches to larval zebrafish behavior analysis, however, it is critical to understand the impact on behavior of experimental variables such as the size of testing arenas and the choice of embryo medium. Using a custom-built, modular high-throughput testing system, we examined the effects of 4 testing arena sizes and 11 types of embryo media on conserved sensorimotor behaviors in zebrafish larvae. Our data show that testing arena size impacts acoustic startle sensitivity and kinematics, as well as spontaneous locomotion and thigmotaxis, with fish tested in larger arenas displaying reduced startle sensitivity and increased locomotion. We also find that embryo media can dramatically affect startle sensitivity, kinematics, habituation, and prepulse inhibition, as well as spontaneous swimming, turning, and overall activity. Common medium components such as methylene blue and high calcium concentration consistently reduced startle sensitivity and locomotion. To further address how the choice of embryo medium can impact phenotype expression in zebrafish models of disease, we reared chd7 mutant larvae, a model of CHARGE syndrome with previously characterized morphological and behavioral phenotypes, in five different types of media and observed impacts on all phenotypes. By defining the effects of these key extrinsic factors on larval zebrafish behavior, these data can help researchers select the most appropriate conditions for their specific research questions, particularly for genetic and chemical screens.

Ocular manifestations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) are among the most common birth defects worldwide and a major cause of kidney failure in children. Extra-renal manifestations are also common. This study reviewed diseases associated with the Genomics England CAKUT-associated gene panel for ocular anomalies. In addition, each gene was examined for expression in the human retina and an ocular phenotype in mouse models using the Human Protein Atlas and Mouse Genome Informatics databases, respectively. Thirty-four (54%) of the 63 CAKUT-associated genes (55 'green' and 8 'amber') had a reported ocular phenotype. Five of the 6 most common CAKUT-associated genes (PAX2, EYA1, SALL1, GATA3, PBX1) that represent 30% of all diagnoses had ocular features. The ocular abnormalities found with most CAKUT-associated genes and with five of the six commonest were coloboma, microphthalmia, optic disc anomalies, refraction errors (astigmatism, myopia, and hypermetropia), and cataract. Seven of the CAKUT-associated genes studied (11%) had no reported ocular features but were expressed in the human retina or had an ocular phenotype in a mouse model, which suggested further possibly-unrecognised abnormalities. About one third of CAKUT-associated genes (18, 29%) had no ocular associations and were not expressed in the retina, and the corresponding mouse models had no ocular phenotype. Ocular abnormalities in individuals with CAKUT suggest a genetic basis for the disease and sometimes indicate the affected gene. Individuals with CAKUT often have ocular abnormalities and may require an ophthalmic review, monitoring, and treatment to preserve vision.

Human Genetics of Tetralogy of Fallot and Double-Outlet Right Ventricle

Tetralogy of Fallot (TOF) and double-outlet right ventricle (DORV) are conotruncal defects resulting from disturbances of the second heart field and the neural crest, which can occur as isolated malformations or as part of multiorgan syndromes. Their etiology is multifactorial and characterized by overlapping genetic causes. In this chapter, we present the different genetic alterations underlying the two diseases, which range from chromosomal abnormalities like aneuploidies and structural mutations to rare single nucleotide variations affecting distinct genes. For example, mutations in the cardiac transcription factors NKX2-5, GATA4, and HAND2 have been identified in isolated TOF cases, while mutations of TBX5 and 22q11 deletion, leading to haploinsufficiency of TBX1, cause Holt-Oram and DiGeorge syndrome, respectively. Moreover, genes involved in signaling pathways, laterality determination, and epigenetic mechanisms have also been found mutated in TOF and/or DORV patients. Finally, genome-wide association studies identified common single nucleotide polymorphisms associated with the risk for TOF.

Genetic Underpinnings and Audiological Characteristics in Children With Unilateral Sensorineural Hearing Loss

OBJECTIVE

Unilateral sensorineural hearing loss (USNHL) is a condition commonly encountered in otolaryngology clinics. However, its molecular pathogenesis remains unclear. This study aimed to investigate the genetic underpinnings of childhood USNHL and analyze the associated audiological features.

STUDY DESIGN

Retrospective analysis of a prospectively recruited cohort.

SETTING

Tertiary referral center.

METHODS

We enrolled 38 children with USNHL between January 1, 2018, and December 31, 2021, and performed physical, audiological, imaging, and congenital cytomegalovirus (cCMV) examinations as well as genetic testing using next-generation sequencing (NGS) targeting 30 deafness genes. The audiological results were compared across different etiologies.

RESULTS

Causative genetic variants were identified in 8 (21.1%) patients, including 5 with GJB2 variants, 2 with PAX3 variants, and 1 with the EDNRB variant. GJB2 variants were found to be associated with mild-to-moderate USNHL in various audiogram configurations, whereas PAX3 and EDNRB variants were associated with profound USNHL in flat audiogram configurations. In addition, whole-genome sequencing and extended NGS targeting 213 deafness genes were performed in 2 multiplex families compatible with autosomal recessive inheritance; yet no definite causative variants were identified. Cochlear nerve deficiency and cCMV infection were observed in 9 and 2, respectively, patients without definite genetic diagnoses.

CONCLUSION

Genetic underpinnings can contribute to approximately 20% of childhood USNHL, and different genotypes are associated with various audiological features. These findings highlight the utility of genetic examinations in guiding the diagnosis, counseling, and treatment of USNHL in children.

Syndromic Hearing Loss in Children

Pattern recognition of specific temporal bone radiological phenotypes, in association with abnormalities in other organ systems, is critical in the diagnosis and management of syndromic causes of hearing loss. Several recent publications have demonstrated the presence of specific radiological appearances, allowing precise genetic and/or syndromic diagnosis, in the right clinical context. This review article aims to provide an extensive but practical guide to the radiologist dealing with syndromic causes of hearing loss.

AI-based diagnosis in mandibulofacial dysostosis with microcephaly using external ear shapes

Introduction

Mandibulo-Facial Dysostosis with Microcephaly (MFDM) is a rare disease with a broad spectrum of symptoms, characterized by zygomatic and mandibular hypoplasia, microcephaly, and ear abnormalities. Here, we aimed at describing the external ear phenotype of MFDM patients, and train an Artificial Intelligence (AI)-based model to differentiate MFDM ears from non-syndromic control ears (binary classification), and from ears of the main differential diagnoses of this condition (multi-class classification): Treacher Collins (TC), Nager (NAFD) and CHARGE syndromes.

Methods

The training set contained 1,592 ear photographs, corresponding to 550 patients. We extracted 48 patients completely independent of the training set, with only one photograph per ear per patient. After a CNN-(Convolutional Neural Network) based ear detection, the images were automatically landmarked. Generalized Procrustes Analysis was then performed, along with a dimension reduction using PCA (Principal Component Analysis). The principal components were used as inputs in an eXtreme Gradient Boosting (XGBoost) model, optimized using a 5-fold cross-validation. Finally, the model was tested on an independent validation set.

Results

We trained the model on 1,592 ear photographs, corresponding to 1,296 control ears, 105 MFDM, 33 NAFD, 70 TC and 88 CHARGE syndrome ears. The model detected MFDM with an accuracy of 0.969 [0.838-0.999] (p < 0.001) and an AUC (Area Under the Curve) of 0.975 within controls (binary classification). Balanced accuracies were 0.811 [0.648-0.920] (p = 0.002) in a first multiclass design (MFDM vs. controls and differential diagnoses) and 0.813 [0.544-0.960] (p = 0.003) in a second multiclass design (MFDM vs. differential diagnoses).

Conclusion

This is the first AI-based syndrome detection model in dysmorphology based on the external ear, opening promising clinical applications both for local care and referral, and for expert centers.

Effects of 4 testing arena sizes and 11 types of embryo media on sensorimotor behaviors in wild-type and chd7 mutant zebrafish larvae: Media and arena size impact zebrafish behavior

The larval zebrafish is a highly versatile model across research disciplines, and the expanding use of behavioral analysis has contributed to many advances in neuro-psychiatric, developmental, and toxicological studies, often through large-scale chemical and genetic screens. In the absence of standardized approaches to larval zebrafish behavior analysis, however, it is critical to understand the impact on behavior of experimental variables such as the size of testing arenas and the choice of embryo medium. Using a custom-built, modular high-throughput testing system, we examined the effects of 4 testing arena sizes and 11 types of embryo media on conserved sensorimotor behaviors in zebrafish larvae. Our data show that testing arena size impacts acoustic startle sensitivity and kinematics as well as spontaneous locomotion and thigmotaxis, with fish tested in larger arenas displaying reduced startle sensitivity and increased locomotion. We also find that embryo media can dramatically affect startle sensitivity, kinematics, habituation, and pre-pulse inhibition, as well as spontaneous swimming, turning, and overall activity. Common media components such as methylene blue and high calcium concentration consistently reduced startle sensitivity and locomotion. To further address how the choice of embryo medium can impact phenotype expression in zebrafish models of disease, we reared chd7 mutant larvae, a model of CHARGE syndrome with previously characterized morphological and behavioral phenotypes, in 5 different types of media and observed impacts on all phenotypes. By defining the effects of these key extrinsic factors on larval zebrafish behavior, these data can help researchers select the most appropriate conditions for their specific research questions, particularly for genetic and chemical screens.

Clinical Presentations and Diagnostic Imaging of VACTERL Association

Background: VACTERL association consists of Vertebral, Anorectal, Cardiac, Tracheo-Esophageal, Renal, and Limb defects. The diagnosis depends on the presence of at least three of these structural abnormalities. Methods: The clinical presentation and diagnostic prenatal imaging of VACTERL association are comprehensively reviewed. Results: The most common feature is a vertebral anomaly, found in 60-80% of cases. Tracheo-esophageal fistula is seen in 50-80% of cases and renal malformations in 30% of patients. Limb defects including thumb aplasia/hypoplasia, polydactyly, and radial agenesis/hypoplasia are present in 40-50% of cases. Anorectal defects, like imperforate anus/anal atresia, are challenging to detect prenatally. Conclusion: The diagnosis of VACTERL association mostly relies on imaging techniques such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis should exclude similar diseases such as CHARGE and Townes-Brocks syndromes and Fanconi anemia. New insights into genetic etiology have led to recommendations of chromosomal breakage investigation for optimal diagnosis and counseling.

Chromatin regulators in the TBX1 network confer risk for conotruncal heart defects in 22q11.2DS

Congenital heart disease (CHD) affecting the conotruncal region of the heart, occurs in 40-50% of patients with 22q11.2 deletion syndrome (22q11.2DS). This syndrome is a rare disorder with relative genetic homogeneity that can facilitate identification of genetic modifiers. Haploinsufficiency of TBX1, encoding a T-box transcription factor, is one of the main genes responsible for the etiology of the syndrome. We suggest that genetic modifiers of conotruncal defects in patients with 22q11.2DS may be in the TBX1 gene network. To identify genetic modifiers, we analyzed rare, predicted damaging variants in whole genome sequence of 456 cases with conotruncal defects and 537 controls, with 22q11.2DS. We then performed gene set approaches and identified chromatin regulatory genes as modifiers. Chromatin genes with recurrent damaging variants include EP400, KAT6A, KMT2C, KMT2D, NSD1, CHD7 and PHF21A. In total, we identified 37 chromatin regulatory genes, that may increase risk for conotruncal heart defects in 8.5% of 22q11.2DS cases. Many of these genes were identified as risk factors for sporadic CHD in the general population. These genes are co-expressed in cardiac progenitor cells with TBX1, suggesting that they may be in the same genetic network. The genes KAT6A, KMT2C, CHD7 and EZH2, have been previously shown to genetically interact with TBX1 in mouse models. Our findings indicate that disturbance of chromatin regulatory genes impact the TBX1 gene network serving as genetic modifiers of 22q11.2DS and sporadic CHD, suggesting that there are some shared mechanisms involving the TBX1 gene network in the etiology of CHD.

Morphological and sensorimotor phenotypes in a zebrafish CHARGE syndrome model are domain-dependent

CHARGE syndrome is a heterogeneous disorder characterized by a spectrum of defects affecting multiple tissues and behavioral difficulties such as autism, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety, and sensory deficits. Most CHARGE cases arise from de novo, loss-of-function mutations in chromodomain-helicase-DNA-binding-protein-7 (CHD7). CHD7 is required for processes such as neuronal differentiation and neural crest cell migration, but how CHD7 affects neural circuit function to regulate behavior is unclear. To investigate the pathophysiology of behavioral symptoms in CHARGE, we established a mutant chd7 zebrafish line that recapitulates multiple CHARGE phenotypes including ear, cardiac, and craniofacial defects. Using a panel of behavioral assays, we found that chd7 mutants have specific auditory and visual behavior deficits that are independent of defects in sensory structures. Mauthner cell-dependent short-latency acoustic startle responses are normal in chd7 mutants, while Mauthner-independent long-latency responses are reduced. Responses to sudden decreases in light are also reduced in mutants, while responses to sudden increases in light are normal, suggesting that the retinal OFF pathway may be affected. Furthermore, by analyzing multiple chd7 alleles we observed that the penetrance of morphological and behavioral phenotypes is influenced by genetic background but that it also depends on the mutation location, with a chromodomain mutation causing the highest penetrance. This pattern is consistent with analysis of a CHARGE patient dataset in which symptom penetrance was highest in subjects with mutations in the CHD7 chromodomains. These results provide new insight into the heterogeneity of CHARGE and will inform future work to define CHD7-dependent neurobehavioral mechanisms.

phox2ba: The Potential Genetic Link behind the Overlap in the Symptomatology between CHARGE and Central Congenital Hypoventilation Syndromes

CHARGE syndrome typically results from mutations in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7). CHD7 is involved in regulating neural crest development, which gives rise to tissues of the skull/face and the autonomic nervous system (ANS). Individuals with CHARGE syndrome are frequently born with anomalies requiring multiple surgeries and often experience adverse events post-anesthesia, including oxygen desaturations, decreased respiratory rates, and heart rate abnormalities. Central congenital hypoventilation syndrome (CCHS) affects ANS components that regulate breathing. Its hallmark feature is hypoventilation during sleep, clinically resembling observations in anesthetized CHARGE patients. Loss of PHOX2B (paired-like homeobox 2b) underlies CCHS. Employing a chd7-null zebrafish model, we investigated physiologic responses to anesthesia and compared these to loss of phox2b. Heart rates were lower in chd7 mutants compared to the wild-type. Exposure to tricaine, a zebrafish anesthetic/muscle relaxant, revealed that chd7 mutants took longer to become anesthetized, with higher respiratory rates during recovery. chd7 mutant larvae demonstrated unique phox2ba expression patterns. The knockdown of phox2ba reduced larval heart rates similar to chd7 mutants. chd7 mutant fish are a valuable preclinical model to investigate anesthesia in CHARGE syndrome and reveal a novel functional link between CHARGE syndrome and CCHS.

Expanding the reproductive organ phenotype of CHD7-spectrum disorder

CHD7 disorder is a multiple congenital anomaly syndrome with a highly variable phenotypic spectrum, and includes CHARGE syndrome. Internal and external genital phenotypes frequently seen in CHD7 disorder include cryptorchidism and micropenis in males, and vaginal hypoplasia in females, both thought to be secondary to hypogonadotropic hypogonadism. Here, we report 14 deeply phenotyped individuals with known CHD7 variants (9 pathogenic/likely pathogenic and 5 VOUS) and a range of reproductive and endocrine phenotypes. Reproductive organ anomalies were observed in 8 of 14 individuals and were more commonly noted in males (7/7), most of whom presented with micropenis and/or cryptorchidism. Kallmann syndrome was commonly observed among adolescents and adults with CHD7 variants. Remarkably, one 46,XY individual presented with ambiguous genitalia, cryptorchidism with Müllerian structures including uterus, vagina and fallopian tubes, and one 46,XX female patient presented with absent vagina, uterus and ovaries. These cases expand the genital and reproductive phenotype of CHD7 disorder to include two individuals with genital/gonadal atypia (ambiguous genitalia), and one with Müllerian aplasia.

Early Steps towards Hearing: Placodes and Sensory Development

Sensorineural hearing loss is the most prevalent sensory deficit in humans. Most cases of hearing loss are due to the degeneration of key structures of the sensory pathway in the cochlea, such as the sensory hair cells, the primary auditory neurons, and their synaptic connection to the hair cells. Different cell-based strategies to replace damaged inner ear neurosensory tissue aiming at the restoration of regeneration or functional recovery are currently the subject of intensive research. Most of these cell-based treatment approaches require experimental in vitro models that rely on a fine understanding of the earliest morphogenetic steps that underlie the in vivo development of the inner ear since its initial induction from a common otic-epibranchial territory. This knowledge will be applied to various proposed experimental cell replacement strategies to either address the feasibility or identify novel therapeutic options for sensorineural hearing loss. In this review, we describe how ear and epibranchial placode development can be recapitulated by focusing on the cellular transformations that occur as the inner ear is converted from a thickening of the surface ectoderm next to the hindbrain known as the otic placode to an otocyst embedded in the head mesenchyme. Finally, we will highlight otic and epibranchial placode development and morphogenetic events towards progenitors of the inner ear and their neurosensory cell derivatives.

The spectrum of cochlear malformations in CHARGE syndrome and insights into the role of the CHD7 gene during embryogenesis of the inner ear

PURPOSE

We reviewed the genotypes and the imaging appearances of cochleae in CHARGE patients from two large tertiary centres and analysed the observed cochlear anomalies, providing detailed anatomical description and a grading system. The goal was to gain insight into the spectrum of cochlear anomalies in CHARGE syndrome, and thus, in the role of the CHD7 gene in otic vesicle development.

METHODS

We retrospectively reviewed CT and/or MR imaging of CHARGE patients referred to our institutions between 2005 and 2022. Cochlear morphology was analysed and, when abnormal, divided into 3 groups in order of progressive severity. Other radiological findings in the temporal bone were also recorded. Comparison with the existing classification system of cochlear malformation was also attempted.

RESULTS

Cochlear morphology in our CHARGE cohort ranged from normal to extreme hypoplasia. The most common phenotype was cochlear hypoplasia in which the basal turn was relatively preserved, and the upper turns were underdeveloped. All patients in the cohort had absent or markedly hypoplastic semicircular canals and small, misshapen vestibules. Aside from a stenotic cochlear aperture (fossette) being associated with a hypoplastic or absent cochlear nerve, there was no consistent relationship between cochlear nerve status (normal, hypoplasia, or aplasia) and cochlear morphology.

CONCLUSION

Cochlear morphology in CHARGE syndrome is variable. Whenever the cochlea was abnormal, it was almost invariably hypoplastic. This may shed light on the role of CHD7 in cochlear development. Accurate morphological description of the cochlea contributes to proper clinical diagnosis and is important for planning surgical treatment options.

Patterns of co-occurring birth defects in children with anotia and microtia

Many infants with anotia or microtia (A/M) have co-occurring birth defects, although few receive syndromic diagnoses in the perinatal period. Evaluation of co-occurring birth defects in children with A/M could identify patterns indicative of undiagnosed/unrecognized syndromes. We obtained information on co-occurring birth defects among infants with A/M for delivery years 1999-2014 from the Texas Birth Defects Registry. We calculated observed-to-expected ratios (OER) to identify birth defect combinations that occurred more often than expected by chance. We excluded children diagnosed with genetic or chromosomal syndromes from analyses. Birth defects and syndromes/associations diagnosed ≤1 year of age were considered. We identified 1310 infants with non-syndromic A/M, of whom 38% (N = 492) were diagnosed with co-occurring major defects. Top combinations included: hydrocephalus, ventricular septal defect, and spinal anomalies (OER 58.4); microphthalmia and anomalies of the aorta (OER 55.4); and cleft lip with or without cleft palate and rib or sternum anomalies (OER 32.8). Some combinations observed in our study may represent undiagnosed/atypical presentations of known A/M associations or syndromes, or novel syndromes yet to be described in the literature. Careful evaluation of infants with multiple birth defects including A/M is warranted to identify individuals with potential genetic or chromosomal syndromes.

Predicting the clinical trajectory of feeding and swallowing abilities in CHARGE syndrome

To date, the feeding and oral-motor abilities of patients with CHARGE syndrome (CS) have not been longitudinally assessed. This study aims to investigate the level of these abilities at different ages and evaluate how they evolve during growth. We retrospectively analysed oral-motor features of 16 patients with molecularly confirmed CS (age range 4-21 years old; mean 11 years; SD 6 years; median 10 years). Nearly 100% of CS new-borns had weak sucking at birth, and half of them demonstrated poor coordination between breathing and swallowing. Over time, the percentages of children with tube feeding dependence (60% at birth) faced a slow but steady decrease (from 33% at 6 months, 25% at 12 months, to 13% at school age) in tandem with the decreasing risk of aspiration. The ability of eating foods requiring chewing was achieved at school age, after the acquisition of an adequate oral sensory processing. A mature chewing pattern with a variety of food textures was not achieved by more than half of patients, including those requiring artificial enteral nutrition. Most patients started prolonged oral-motor treatments with speech language therapists in early childhood.

CONCLUSIONS

Although feeding and swallowing disorders are constant features in CS patients, a slow and gradual development of feeding abilities occurs in most cases. Rehabilitation plays a key role in overcoming structural and functional difficulties and attaining appropriate eating skills.

WHAT IS KNOWN

• Feeding problems and swallowing dysfunction have been noted in CHARGE syndrome. • The involvement of multiple factors, including structural problems in the mouth, throat, or esophagus, and neurological impairment, make feeding a complicated task in CHARGE individuals.

WHAT IS NEW

• Dysphagia gradually improves in most CHARGE children over time, though with a wide interindividual variability. • The percentages of children with tube feeding dependence decrease over time from 60% at birth to 33% at 6 months and 13% at school age.

The role of the pregnancy heart team in clinical practice

Significant maternal and fetal morbidity and mortality risk has been shown to be associated with cardiovascular disease in pregnancy. Several determinants, such as the increasing number of females with corrected congenital heart disease in reproductive age, a more advanced maternal age associated with cardiovascular risk factors, and a greater prevalence of preexisting comorbidities related to cardiac disorders such as cancer and COVID-19), lead to a higher incidence of cardiac complications in pregnancy in the last few decades. However, adopting a multidisciplinary strategy may influence maternal and neonatal outcomes. This review aims at assessing the role of the Pregnancy Heart Team, which should ensure careful pre-pregnancy counseling, pregnancy monitoring, and delivery planning for both congenital and other cardiac or metabolic disorders, addressing several emerging aspects in the multidisciplinary team-based approach.

Factors associated with nonsyndromic anotia and microtia, Texas, 1999-2014

BACKGROUND

Few risk factors have been identified for nonsyndromic anotia/microtia (A/M).

METHODS

We obtained data on cases and a reference population of all livebirths in Texas for 1999-2014 from the Texas Birth Defects Registry (TBDR) and Texas vital records. We estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) for A/M (any, isolated, nonisolated, unilateral, and bilateral) using Poisson regression. We evaluated trends in prevalence rates using Joinpoint regression.

RESULTS

We identified 1,322 cases, of whom 982 (74.3%) had isolated and 1,175 (88.9%) had unilateral A/M. Prevalence was increased among males (PR: 1.3, 95% CI: 1.2-1.4), offspring of women with less than high school education (PR: 1.3, 95% CI: 1.1-1.5), diabetes (PR: 2.0, 95% CI: 1.6-2.4), or age 30-39 versus 20-29 years (PR: 1.2, 95% CI: 1.0-1.3). The prevalence was decreased among offspring of non-Hispanic Black versus White women (PR: 0.6, 95% CI: 0.4-0.8) but increased among offspring of Hispanic women (PR: 2.9, 95% CI: 2.5-3.4) and non-Hispanic women of other races (PR: 1.7, 95% CI: 1.3-2.3). We observed similar results among cases with isolated and unilateral A/M. Sex disparities were not evident for nonisolated or bilateral phenotypes, nor did birth prevalence differ between offspring of non-Hispanic Black and non-Hispanic White women. Maternal diabetes was more strongly associated with nonisolated (PR: 4.5, 95% CI: 3.2-6.4) and bilateral A/M (PR: 5.0, 95% CI: 3.3-7.7). Crude prevalence rates increased throughout the study period (annual percent change: 1.82).

CONCLUSION

We identified differences in the prevalence of nonsyndromic A/M by maternal race/ethnicity, education, and age, which may be indicators of unidentified social/environmental risk factors.

Chromatin remodeler CHD7 targets active enhancer region to regulate cell type-specific gene expression in human neural crest cells

A mutation in the chromatin remodeler chromodomain helicase DNA-binding 7 (CHD7) gene causes the multiple congenital anomaly CHARGE syndrome. The craniofacial anomalies observed in CHARGE syndrome are caused by dysfunctions of neural crest cells (NCCs), which originate from the neural tube. However, the mechanism by which CHD7 regulates the function of human NCCs (hNCCs) remains unclear. We aimed to characterize the cis-regulatory elements governed by CHD7 in hNCCs by analyzing genome-wide ChIP-Seq data and identifying hNCC-specific CHD7-binding profiles. We compared CHD7-binding regions among cell types, including human induced pluripotent stem cells and human neuroepithelial cells, to determine the comprehensive properties of CHD7-binding in hNCCs. Importantly, analysis of the hNCC-specific CHD7-bound region revealed transcription factor AP-2α as a potential co-factor facilitating the cell type-specific transcriptional program in hNCCs. CHD7 was strongly associated with active enhancer regions, permitting the expression of hNCC-specific genes to sustain the function of hNCCs. Our findings reveal the regulatory mechanisms of CHD7 in hNCCs, thus providing additional information regarding the transcriptional programs in hNCCs.

Characteristics of Choanal Atresia in Patients With Congenital Anomalies: A Retrospective Study

Introduction

Choanal atresia (CA) is an uncommon congenital anomaly. There are various syndromes that are associated with CA. The purpose of this study is to determine the differences in CA's presentation and outcome when associated with other congenital anomalies and syndromes.

Method

This is a retrospective review study of all children (18 years and younger) who underwent CA repair in a tertiary referral healthcare center from January 2005 to April 2022. Demographics, comorbidities, radiological testing, operative reports, and outpatient reports were collected. Success was determined as a child with bilateral patent choana that is able to breathe from both nostrils comfortably.

Result

Twenty-four patients met the criteria for inclusion in this study. Bilateral CA was present in 15 (62.5%) patients. Mixed CA was the most common variant. There were various congenital anomalies in association with CA patients who are yet to be classified into a syndrome. The most common congenital anomaly was cleft lip and palate. Bony and mixed types were significantly associated with non-syndromic patients (p<0.05). Twenty patients (83%) were diagnosed with CA at age of less than one year, and four patients were diagnosed after one year of age. There were 36 surgeries performed on 24 patients, of which 27 were endoscopic and nine were using Hugher dilator. The overall success rate for CA repair was 50%. The median number of revisions per patient was 0.5.

Conclusion

CA is a challenging anomaly to repair. There are various factors that influence the outcome of children with CA. Otolaryngologists should counsel the patient and their families regarding possible need for revision especially in those with other craniofacial anomalies.

Eyes on CHARGE syndrome: Roles of CHD7 in ocular development

The development of the vertebrate visual system involves complex morphogenetic interactions of cells derived from multiple embryonic lineages. Disruptions in this process are associated with structural birth defects such as microphthalmia, anophthalmia, and coloboma (collectively referred to as MAC), and inherited retinal degenerative diseases such as retinitis pigmentosa and allied dystrophies. MAC and retinal degeneration are also observed in systemic congenital malformation syndromes. One important example is CHARGE syndrome, a genetic disorder characterized by coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Mutations in the gene encoding Chromodomain helicase DNA binding protein 7 (CHD7) cause the majority of CHARGE syndrome cases. However, the pathogenetic mechanisms that connect loss of CHD7 to the ocular complications observed in CHARGE syndrome have not been identified. In this review, we provide a general overview of ocular development and congenital disorders affecting the eye. This is followed by a comprehensive description of CHARGE syndrome, including discussion of the spectrum of ocular defects that have been described in this disorder. In addition, we discuss the current knowledge of CHD7 function and focus on its contributions to the development of ocular structures. Finally, we discuss outstanding gaps in our knowledge of the role of CHD7 in eye formation, and propose avenues of investigation to further our understanding of how CHD7 activity regulates ocular and retinal development.

[Antenatal ear examination: When, how and why?]

Antenatal ear examination is an integral part of the thorough examination of the fetal face. The discovery of an anomaly, whether it is made by chance or during a complementary in-depth examination, leads the practitioner to determine its isolated or associated character, in order to characterise its possible belonging to a syndromic entity. In this context, the realization of genetic analysis more precise and wider allowing a return of the results in a time compatible with an evolutive pregnancy, gives to the geneticist a central role in the management of these couples. The main challenge lies in obtaining a set of concordant clinical and biological clues, enabling the genetic results identified to be interpreted correctly, the optimised functioning of the ultrasound practitioner - geneticist duo is therefore fundamental. This results in a complex information to deliver, in the fact that the clinical translation of an ear anomaly in antenatal can go from an isolated aesthetic anomaly to a genetic syndrome with neurodevelopmental disorder. The objective of this work is to describe, from a methodological analysis of antenatal ears, the accessible malformative entities, isolated or associated, and to discuss the problems in the need or not to propose their screening.

Genetic mouse models of autism spectrum disorder present subtle heterogenous cardiac abnormalities

Autism spectrum disorder (ASD) and congenital heart disease (CHD) are linked on a functional and genetic level. Most work has investigated CHD‐related neurodevelopmental abnormalities. Cardiac abnormalities in ASD have been less studied. We investigated the prevalence of cardiac comorbidities relative to ASD genetic contributors. Using high frequency ultrasound imaging, we screened 9 ASD‐related genetic mouse models (Arid1b^(+/−), Chd8^(+/−), 16p11.2 (deletion), Sgsh^(+/−), Sgsh^(−/−), Shank3 Δexon 4–9^(+/−), Shank3 Δexon 4–9^(−/−), Fmr1^(−/−), Vps13b^(+/−)), and pooled wild‐type littermates (WTs). We measured heart rate (HR), aorta diameter (AoD), thickness and thickening of the left‐ventricular (LV) anterior and posterior walls, LV chamber diameter, fractional shortening, stroke volume and cardiac output, mitral inflow Peak E and A velocity ratio, ascending aorta velocity time integral (VTI). Mutant groups presented small‐scale alterations in cardiac structure and function compared to WTs (LV anterior wall thickness and thickening, chamber diameter and fractional shortening, HR). A greater number of significant differences was observed among mutant groups than between mutant groups and WTs. Mutant groups differed primarily in structural measures (LV chamber diameter and anterior wall thickness, HR, AoD). The mutant groups with most differences to WTs were 16p11.2 (deletion), Fmr1^(−/−), Arid1b^(+/−). The mutant groups with most differences from other mutant groups were 16p11.2 (deletion), Sgsh^(+/−), Fmr1^(−/−). Our results recapitulate the associated clinical findings. The characteristic ASD heterogeneity was recapitulated in the cardiac phenotype. The type of abnormal measures (morphological, functional) can highlight common underlying mechanisms. Clinically, knowledge of cardiac abnormalities in ASD can be essential as even non‐lethal abnormalities impact normal development.

[CHARGE syndrome in children with congenital choanal atresia]

One of the most commonly associated genetic syndromes with congenital choanal atresia is CHARGE syndrome, which includes multiple congenital anomalies with variable phenotypic manifestations. The article presents data on the history of the study, prevalence, etiology and clinical criteria of this pathology.

OBJECTIVE

To determine the frequency of detection and features of clinical manifestations of CHARGE syndrome in children with congenital choanal atresia.

MATERIAL AND METHODS

Based on the literature data and our own research, the features of the clinical manifestations of CHARGE syndrome in children with congenital choanal atresia are presented.

RESULTS

The association of malformations, which in most cases had bilateral localization, was detected in 27 (18.8%) patients with congenital choanal atresia. In 20 children, the analysis for the presence of the CHD7 mutation was carried out by sequencing, while CHD7 mutations were detected in 18 (90%) patients meeting the clinical criteria of CHARGE syndrome. The absence of mutations of the CHD7 gene in the remaining patients indicates the genetic heterogeneity of this syndrome.

CONCLUSION

The detection of CHARGE syndrome in children with congenital choanal atresia is of great clinical importance, since timely diagnosis and correction of other pathology minimizes the chance of complications during surgical treatment and allows for the formation of individual routing of patients for treatment and rehabilitation. Therefore, the examination and management of children with congenital choanal atresia associated with other malformations should be carried out on the basis of an interdisciplinary approach.

An aborted case suspected to CHARGE Syndrome; A rare case with cardiac, intestinal and kidney abnormalities

Background

CHARGE syndrome is a life-threatening congenital anomaly. The syndrome associations consist of coloboma, heart disease, atresia of the choanae, retarded growth and development, genital hypoplasia/genitourinary anomalies, and ear anomalies and or hearing loss. The aim of this paper is to describe and discuss a rare case of CHARGE syndrome.

Case presentation

During the routine dissection, atrial septal defect, overriding aorta from both ventricles, patent ductus arteriosus, duodenal anomaly, absent pancreas, right side descending and sigmoid, intestinal herniation in lesser sac, and left kidney anomaly were observed.

Conclusions

This rare case is of importance in re-considering the criteria of CHARGE and understanding the importance of the orchestrated morphologic driving forces of embryonic development.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Affordances for Motor Development in the Home Environment for Young Children with and without CHARGE Syndrome

Affordances in the home environment are critical to early motor development. Currently, the home environment has not been examined in children with deafblindness or severe disabilities. The present study examined differences in, and relationships between, the home environment and motor development in children with and without CHARGE syndrome. CHARGE syndrome is a low-incidence, complex disorder with sensory and motor impairments. Participants included 28 parents of children with CHARGE syndrome and 32 parents of children without disabilities. Children with CHARGE syndrome achieved motor milestones significantly later and had fewer outside space affordances than children without disabilities. Older children had a greater variety of stimulation and fine motor toys, and those that achieved independent walking later had more outside space and fine and gross motor toys. Early experiences may be more important for children with CHARGE syndrome than children without disabilities. Moreover, parents can play a vital role in their children’s motor development to help them reach their motor milestones.

[Cochlear implant and surgical intervention for CHARGE syndrome with laryngeal airway lesions]

Objective:To evaluate the clinical efficacy of surgical intervention for laryngeal airway lesions with concurrent cochlear implantation in CHARGE syndrome concomitant laryngeal airway lesions, and provide clinical data for cochlear implantation in children with CHARGE syndrome concomitant laryngeal airway lesions. Methods:The medical records of five cases diagnosed with CHARGE syndrome were retrospectively reviewed, two of them treated with surgical intervention for laryngeal airway lesions and concurrent cochlear implantation. One child treated with balloon dilatation of laryngeal stenosis and Cochlear implant, and another case received with modified supraglottoplasty for laryngeal malacia and Cochlear implant. Results:Two cases of CHARGE syndrome concomitant laryngeal airway disease, who underwent Cochlear implant and concurrent surgical intervention, recovered well after treatment. The remining three cases treated with Cochlear implant, who previously received deformity-correction surgery. All of the five cases presented with CHD7 mutation. Conclusion:Cochlear implant concurrent with surgical intervention of laryngeal airway lesions for the treatment of CHARGE syndrome concomitant laryngeal airway disease was safe and efficient, which could be a treatment option for children in this situation.

CHARGE syndrome: A case report of two new CDH7 gene mutations

CHARGE syndrome is a genetic disorder comprising the following clinical features: coloboma, heart defects, choanal atresia, retardation (of growth and development), as well as genitourinary and ear abnormalities. This syndrome is caused by mutations in the CDH7 gene, located on chromosome 8 (8q12). We present two new gene mutations in two patients with CHARGE syndrome, not previously reported in the scientific literature. Both of these patients clearly demonstrate the difference in the clinical expression of this syndrome, with patient 1 having a greater clinical severity compared to patient 2. We conclude that although in the scientific literature to date there is no clear correlation between a patient's genotype and phenotype expression, we can assume from the cases we present that a correlation does in fact exist. Specifically, missense mutations (as in case of patient 2) are associated with milder clinical expression, whereas mutations which result in truncation of the CDH7 protein (as in the case of patient 1 having a nonsense mutation) may be associated with a more severe clinical expression.

Modeling human congenital disorders with neural crest developmental defects using patient-derived induced pluripotent stem cells

The neural crest is said to be the fourth germ layer in addition to the ectoderm, mesoderm and endoderm because of its ability to differentiate into a variety of cells that contribute to the various tissues of the vertebrate body. Neural crest cells (NCCs) can be divided into three functional groups: cranial NCCs, cardiac NCCs and trunk NCCs. Defects related to NCCs can contribute to a broad spectrum of syndromes known as neurocristopathies. Studies on the neural crest have been carried out using animal models such as Xenopus, chicks, and mice. However, the precise control of human NCC development has not been elucidated in detail due to species differences. Using induced pluripotent stem cell (iPSC) technology, we developed an in vitro disease model of neurocristopathy by inducing the differentiation of patient-derived iPSCs into NCCs and/or neural crest derivatives. It is now possible to address complicated questions regarding the pathogenetic mechanisms of neurocristopathies by characterizing cellular biological features and transcriptomes and by transplanting patient-derived NCCs in vivo. Here, we provide some examples that elucidate the pathophysiology of neurocristopathies using disease modeling via iPSCs.

New Feeding Assessment Scale for individuals with genetic syndromes: Validity and reliability in the CHARGE syndrome population

AIM

To develop a feeding scale for parents/care givers of individuals of all ages with genetic syndromes experiencing extensive feeding and swallowing problems. Second, to assess its validity and reliability in CHARGE syndrome.

METHODS

The new Feeding Assessment Scale (FAS) was adapted from a scale for children who need prolonged tube feeding (Paediatric Assessment Scale for Severe Feeding Problems, PASSFP). Ten parents piloted the new scale before it was sent out with the PASSFP and feeding history questions. A subset completed the new scale again 4-8 weeks later.

RESULTS

One hundred parents of individuals with CHARGE syndrome participated from around the world. The new scale had good construct validity, with a significant effect for an increased number of feeding risk factors having higher scale scores (P < 0.001). Face validity was high, as scores significantly differed between individuals whose parents identified their feeding difficulties as very mild, mild, moderate, severe and very severe (P < 0.001). Test-retest reliability (r = 0.94, P < 0.001) and internal consistency (Cronbach's alpha 0.91) were both high. There was significant convergent validity between the new scale and the PASSFP (r = -0.79, P < 0.001).

CONCLUSIONS

This new tool is reliable and valid for parents/care givers of individuals with CHARGE syndrome. It can be used to assess the current severity of feeding difficulties and to track progress before and after treatment. It expands upon previous existing tools in that it can be used in both individuals who are not tube fed, as well as in those who are, as well as across the life-span.

A national study of choanal atresia in tertiary care centers in Canada - part I: clinical presentation

Background

To evaluate the clinical presentation of choanal atresia (CA) in tertiary centers across Canada.

Methods

Multi-centre case series involving six tertiary care pediatric hospitals across Canada. Retrospective chart review of patients born between 1980 and 2010 diagnosed with CA at a participating center.

Results

The health charts of 215 patients (59.6% female) with CA were reviewed and included in this study. The mean age of patients at time of CA presentation was 0.4 months (range 0.1 to 7.2 months) for bilateral CA and 37.8 months (range 0.1 to 164.1 months) for unilateral cases. The most common presenting symptoms for bilateral CA in decreasing order were respiratory distress (96.4%), feeding difficulties (68.2%), and rhinorrhea (65.5%), and for unilateral cases in decreasing order were rhinorrhea (92.0%), feeding difficulties (24.7%), and respiratory distress (18.0%). For the majority of patients (73.2%), the obstruction comprised mixed bony and membranous tissue, with only 10.5% presenting with a purely membranous obstruction. Familial history of CA was confirmed in only 3.3% of cases. One half of patients with CA presented with one or more associated anomalies and 30.6% had a syndrome.

Conclusions

The present investigation is the first national multi-institutional study evaluating the clinical presentation of CA over three decades. The present cohort of CA patients presented with a breadth of co-morbidities with highly variable presentations, with bilateral cases being more severely affected than unilateral cases. Further investigation into hereditary linkages to CA development is warranted.

Graphical abstract

Advances in Genetic Diagnosis of Kallmann Syndrome and Genetic Interruption

Kallmann syndrome (KS) is a rare hereditary disease with high phenotypic and genetic heterogeneity. Congenital hypogonadotropic hypogonadism and hyposmia/anosmia are the two major characterized phenotypes of KS. Besides, mirror movements, dental agenesis, digital bone abnormalities, unilateral renal agenesis, midline facial defects, hearing loss, and eye movement abnormalities can also be observed in KS patients. Because of the phenotypic heterogeneity, genetic diagnosis become increasingly valuable to distinguish KS from other disorders including normosmic congenital hypogonadotropic hypogonadism, constitutional delay of growth and puberty, CHARGE syndrome, and functional hypogonadotropic hypogonadism. Application of next-generation sequencing has promoted the discovery of novel pathogenic genes in KS pedigrees. Prenatal diagnosis is an effective method in clinical settings to decrease birth defects and block transmission of genetic disorders. However, pregnant women may suffer from physical and psychological distress when fetuses are diagnosed with congenital defects. Preimplantation genetic testing (PGT) is a prospective approach during the in vitro fertilization process that helps to interrupt transmission of hereditary diseases to offspring at an early stage. Thus, genetic testing and counseling are recommended to KS patients with family histories, prenatal diagnosis and PGT are considered to be useful options.

Bilateral Choanal Atresia and Endoscopic Surgery: A Chance for CHARGE Patients

Bilateral choanal atresia (CA) is a rare congenital malformation frequently associated with other anomalies. CHARGE association is closely linked to bilateral CA. The aim of this study was to describe the outcomes of the endoscopic repair in bilateral CA, and to assess the role of postoperative nasal stenting in two cohorts of CHARGE-associated and non-syndromic CA. Thirty-nine children were retrospectively analyzed (16 patients had CHARGE-associated CA). The rate of postoperative neochoanal restenosis was 31.3% in the CHARGE population, and 47.8% in the non-syndromic CA cohort. Data on postoperative synechiae and granulation tissue formation, need for endonasal toilette and dilation procedures, and number of procedures per patient were presented. Stent positioning led to a higher number of postoperative dilation procedures per patient in the non-syndromic cohort (p = 0.018), and to a higher rate of restenosis both in the CHARGE-associated, and non-syndromic CA populations. Children with CHARGE-associated and non-syndromic bilateral CA benefitted from endonasal endoscopic CA correction. The postoperative application of an endonasal stent should be carefully evaluated.

Transition readiness among adolescents with rare endocrine conditions

OBJECTIVE

Adolescents and young adults (AYA) with common endocrine disorders show a high dropout (up to 50%) after the transfer from paediatric to adult endocrinology. Little is known about transition readiness in rare endocrine conditions (rEC). This study aims to assess medical self-management skills (SMS) among AYA with rEC in relation to age and gender, in order to understand dropout and increase transition readiness.

DESIGN

Cross-sectional study using web-based medical self-management questionnaires.

METHODS

Questionnaires consisting of 54 questions in seven domains were filled out by the adolescents before the first shared appointment with both paediatric and adult endocrinologist.

RESULTS

Fifty-seven patients (median age 17 years, 25/57 females) participated and generally scored well on most items. However, one out of seven did not know the name of their disorder, one sixth of the glucocorticoid users did not know that dose should be adapted in case of illness or surgery, over one-fifth had never ordered their repeat prescriptions themselves and two-thirds had never had a conversation alone with their doctor.

CONCLUSIONS

Several SMS among patients with rEC are insufficient, with regard to medical knowledge, practical skills and communication. As SMS are only weakly related to non-modifiable factors, such as age and gender, we recommend focussing on other factors to increase transition readiness. The timing, amount and 'mode' of medical information should be individualised. Transition checklists should be used to detect shortcomings in practical skills and communication, which can subsequently be trained with the help of parents, caregivers and/or e-technology.

Otopathologic Abnormalities in CHARGE Syndrome

OBJECTIVE

To perform an otopathologic analysis of temporal bones (TBs) with CHARGE syndrome.

STUDY DESIGN

Otopathologic study of human TB specimens.

SETTING

Otopathology laboratories.

METHODS

From the otopathology laboratories at the University of Minnesota and Massachusetts Eye and Ear Infirmary, we selected TBs from donors with CHARGE syndrome. These TBs were serially sectioned at a thickness of 20 µm, and every 10th section was stained with hematoxylin and eosin. We performed otopathologic analyses of the external ear, middle ear (middle ear cleft, mucosal lining, ossicles, mastoid, and facial nerve), and inner ear (cochlea, vestibule, internal auditory canal, and cochlear and vestibular nerves). The gathered data were statistically analyzed.

RESULTS

Our study included 12 TBs from 6 donors. We found a high prevalence of abnormalities affecting the ears. The most frequent findings were stapes malformation (100%), aberrant course of the facial nerve (100%) with narrow facial recess (50%), sclerotic and hypodeveloped mastoids (50%), cochlear (100%) and vestibular (83.3%) hypoplasia with aplasia of the semicircular canals, hypoplasia and aplasia of the cochlear (66.6%) and vestibular (91.6%) nerves, and narrowing of the bony canal of the cochlear nerve (66.6%). The number of spiral ganglion and Scarpa's ganglion neurons were decreased in all specimens (versus normative data).

CONCLUSIONS

In our study, CHARGE syndrome was associated with multiple TB abnormalities that may severely affect audiovestibular function and rehabilitation.

Rare Diseases of the Salivary Glands and of Facial Nerve

Salivary gland diseases are rare. In the European Union (EU) a disease is considered to be rare if not more than 5 of 10,000 people are affected by it. According to estimates in Germany are about 4 million people with a rare disease. In the EU are about 30 million people with rare diseases [1]. In the present work most of the described diseases of salivary glands and of the facial nerve fall in this category. They form a very heterogeneous group whose treatment takes place mainly in specialized centers. Still, it is essential for the otolaryngologist to identify and to diagnose these diseases in order to initiate the right therapeutic steps. The work is a compilation of innate andacquired rare salivary gland disorders and of rare facial nerve disorders. The etiologies of inflammatory diseases, autoimmune disorders and tumors are taken into account. For the individual topics, the current literature, if available, was evaluated and turned into summarized facts. In this context the development of new processes, diagnostics, imaging and therapy are considered. Genetic backgrounds of salivary gland tumors and the trends in the treatment of tumorous lesions of the facial nerve are picked up. Furthermore, also rare diseases of the salivary glands in childhood are described. Some of them can occur in adults as well, but differ in frequency and symptoms. Due to the rarity of these diseases, it is recommended to tread these in centers with special expertise for it. Finally, the difficulties of initiation of studies and the problems of establishing disease registries concerning salivary gland disorders are discussed. This is very relevant because these pathologies are comparatively seldom.

Semaphorin Regulation by the Chromatin Remodeler CHD7: An Emerging Genetic Interaction Shaping Neural Cells and Neural Crest in Development and Cancer

CHD7 is a chromatin remodeler protein that controls gene expression via the formation of multi-protein complexes with specific transcription factors. During development, CHD7 controls several differentiation programs, mainly by acting on neural progenitors and neural crest (NC) cells. Thus, its roles range from the central nervous system to the peripheral nervous system and the organs colonized by NC cells, including the heart. Accordingly, mutated CHD7 is linked to CHARGE syndrome, which is characterized by several neuronal dysfunctions and by malformations of NC-derived/populated organs. Altered CHD7 has also been associated with different neoplastic transformations. Interestingly, recent evidence revealed that semaphorins, a class of molecules involved in developmental and pathological processes similar to those controlled by CHD7, are regulated by CHD7 in a context-specific manner. In this article, we will review the recent insights that support the existence of genetic interactions between these pathways, both during developmental processes and cancer progression.

Pulmonary Manifestations of Immunodeficiency and Immunosuppressive Diseases Other than Human Immunodeficiency Virus

Immune deficiencies may alter normal lung function and protective mechanisms, resulting in a myriad of pulmonary manifestations. Primary immunodeficiencies involve multiple branches of the immune system, and defects may predispose to recurrent upper and lower respiratory infections by common pathogens; opportunistic infections; and autoimmune, inflammatory, and malignant processes that may result in interstitial pneumonias. Secondary immunodeficiencies may result from neoplasms or their treatment, organ transplant and immunosuppression, and from autoimmune diseases and their treatments. Primary and secondary immunodeficiencies and their pulmonary manifestations may be difficult to diagnose and treat. A multidisciplinary approach to evaluation is essential.

Sporadic Case of CHARGE Syndrome With Chromodomain-Helicase-DNA-Binding Protein 7 (CDH7) Gene Mutation

CHARGE syndrome with chromodomain-helicase-DNA-binding protein 7 (CDH7) gene mutation is a genetic disease with an autosomal dominant gene. This syndrome involves a combination of six congenital anomalies (heart anomalies, coloboma of the eye, retardation of the growth or development, atresia of the choana, ear anomalies, and genital anomalies). Here, we present a case of a 15-month-old male child who was born to a 23-year-old healthy mother with no history of any exposure to teratogenic materials or drugs. The patient was delivered by cesarean section because of the failure of progression at 39 weeks of pregnancy with several health problems that started with the respiratory system right after birth. On examination, he was found to be suffering from several congenital anomalies, including heart, face, eyes, ears, and genitalia. A genetic analysis was performed for the patient, and a mutation in the CDH7 gene was found. The patient was diagnosed as a sporadic case of CHARGE syndrome. The patient's treatment plan is a multidisciplinary team effort to alleviate his quality of life and further increase life expectancy.

CHD7 regulates cardiovascular development through ATP-dependent and -independent activities

CHD7 encodes an ATP-dependent chromatin remodeling factor. Mutation of this gene causes multiple developmental disorders, including CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth/development, Genital abnormalities, and Ear anomalies) syndrome, in which conotruncal anomalies are the most prevalent form of heart defects. How CHD7 regulates conotruncal development remains unclear. In this study, we establish that deletion of Chd7 in neural crest cells (NCCs) causes severe conotruncal defects and perinatal lethality, thus providing mouse genetic evidence demonstrating that CHD7 cell-autonomously regulates cardiac NCC development, thereby clarifying a long-standing controversy in the literature. Using transcriptomic analyses, we show that CHD7 fine-tunes the expression of a gene network that is critical for cardiac NCC development. To gain further molecular insights into gene regulation by CHD7, we performed a protein-protein interaction screen by incubating recombinant CHD7 on a protein array. We find that CHD7 directly interacts with several developmental disorder-mutated proteins including WDR5, a core component of H3K4 methyltransferase complexes. This direct interaction suggested that CHD7 may recruit histone-modifying enzymes to target loci independently of its remodeling functions. We therefore generated a mouse model that harbors an ATPase-deficient allele and demonstrates that mutant CHD7 retains the ability to recruit H3K4 methyltransferase activity to its targets. Thus, our data uncover that CHD7 regulates cardiovascular development through ATP-dependent and -independent activities, shedding light on the etiology of CHD7-related congenital disorders. Importantly, our data also imply that patients carrying a premature stop codon versus missense mutations will likely display different molecular alterations; these patients might therefore require personalized therapeutic interventions.