Adolescent and adult issues in CHARGE syndrome

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.

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.

Epigenetics of cognition and behavior: insights from Mendelian disorders of epigenetic machinery

Epigenetics, one mechanism by which gene expression can change without any changes to the DNA sequence, was described nearly a century ago. However, the importance of epigenetic processes to neurodevelopment and higher order neurological functions like cognition and behavior is only now being realized. A group of disorders known as the Mendelian disorders of the epigenetic machinery are caused by the altered function of epigenetic machinery proteins, which consequently affects downstream expression of many genes. These disorders almost universally have cognitive dysfunction and behavioral issues as core features. Here, we review what is known about the neurodevelopmental phenotypes of some key examples of these disorders divided into categories based on the underlying function of the affected protein. Understanding these Mendelian disorders of the epigenetic machinery can illuminate the role of epigenetic regulation in typical brain function and can lead to future therapies and better management for a host of neurodevelopmental and neuropsychological disorders.

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.

Phenotypic characteristics and variability in CHARGE syndrome: a PRISMA compliant systematic review and meta-analysis

Background

CHARGE syndrome (OMIM #214800) is a phenotypically complex genetic condition characterised by multi-system, multi-sensory impairments. Behavioural, psychological, cognitive and sleep difficulties are not well delineated and are likely associated with biopsychosocial factors.

Methods

This meta-analysis investigated the prevalence of clinical features, physical characteristics and conditions, behavioural, psychological, cognitive and sleep characteristics in CHARGE syndrome, and statistically evaluated directional associations between these characteristics. Pooled prevalence estimates were calculated using reliable, prespecified quality weighting criteria, and meta-regression was conducted to identify associations between characteristics.

Results

Of the 42 eligible studies, data could be extracted for 1675 participants. Prevalence estimates were highest for developmental delay (84%), intellectual disability (64%), aggressive behaviour (48%), self-injurious behaviour (44%) and sleep difficulties (45%). Meta-regression indicated significant associations between intellectual disability and choanal atresia, intellectual disability and inner ear anomalies, sleep difficulties and growth deficiency, and sleep difficulties and gross motor difficulties.

Conclusions

Our comprehensive review of clinical features, behavioural, psychological, cognitive and physical characteristics, conditions and comorbidities in CHARGE syndrome provides an empirically based foundation to further research and practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09459-5.

Prevalence of anxiety symptomatology and diagnosis in syndromic intellectual disability: A systematic review and meta-analysis

Individuals with syndromic intellectual disability are at increased risk of experiencing anxiety. Comparing prevalence estimates of anxiety will allow the identification of at-risk groups and inform causal pathways of anxiety. No known study has explored estimates of anxiety symptomatology and diagnosis, including specific anxiety profiles, across groups whilst accounting for methodological quality of studies. This systematic review and meta-analysis aimed to fill this gap. Prior to review completion, methodology and analysis plans were registered and documented in a protocol (CRD42019123561). Data from 83 papers, involving a pooled sample of 13,708 across eight syndromes were synthesised using a random effects model. Anxiety prevalence ranged from 9 % (95 % CI: 4-14) in Down syndrome to 73% in Rett syndrome (95 % CI: 70-77). Anxiety prevalence across syndromic intellectual disability was higher than for intellectual disability of mixed aetiology and general population estimates. Substantial variability between syndromes identified groups at higher risk than others. The identification of high-risk groups is crucial for early intervention, allowing us to refine models of risk and identify divergent profiles.

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.

Care of Children with DiGeorge Before and After Cultured Thymus Tissue Implantation

Background

Children with complete DiGeorge anomaly (cDGA) have congenital athymia plus a myriad of other challenging clinical conditions. The term cDGA encompasses children with congenital athymia secondary to 22q11.2DS, CHARGE syndrome (coloboma, heart defects, choanal atresia, growth or mental retardation, genital abnormalities, and ear abnormalities and/or deafness), and other genetic abnormalities. Some children have no known genetic defects. Since 1993, more than 100 children with congenital athymia have been treated with cultured thymus tissue implantation (CTTI). Naïve T cells develop approximately 6 to 12 months after CTTI. Most of the children had significant comorbidities such as heart disease, hypoparathyroidism, and infections requiring complex clinical care post cultured thymus tissue implantation (CTTI).

Objective

The purpose of this guidance is to assist multidisciplinary teams in caring for children with cDGA both before and after CTTI.

Methods

Thirty-one specialists, in addition to the authors, were asked to share their experience in caring for children with cDGA at Duke University Health System, before and after CTTI. These specialists included physicians, nurses, dentists, therapists, and dieticians.

Results

The goal of a multidisciplinary approach is to have children in the best possible condition for receiving CTTI and provide optimal care post CTTI through development of naïve T cells and beyond. The CTT (cultured thymus tissue) must be protected from high doses of steroids which can damage CTT. Organs must be protected from adverse effects of immunosuppression.

Conclusion

Creating a multidisciplinary team and a detailed plan of care for children with cDGA is important for optimal outcomes.

Parent survey of sleep problems among children with CHARGE syndrome

Sleep problems are common among children, especially those with developmental disabilities, visual impairments, and behavioral problems. Past research has indicated a particularly high prevalence of clinically-relevant sleep problems for children with CHARGE syndrome, who often possess all three of these qualities. To gather additional information regarding the nature of these sleep problems and how they are most commonly treated amongst parents, an explorative survey was conducted with 30 parents of children with CHARGE syndrome with comorbid sleep problems using the Sleep Disturbance Scale for Children, as well as demographic and sleep questionnaires developed for use in this study. Our findings indicated that problems of sleep initiation and maintenance were most commonly reported, consistent with previous research. Parents most often reported the following factors suspected of contributing to sleep problems: self-regulation difficulties, teeth grinding, hormonal imbalance, problem behaviors, and anxiety. The most commonly administered treatments were reported to be the use of positive bedtime routines, melatonin treatment, the use of a weighted blanket, and prescription medications, respectively. While parents reported overall that they felt all three of these intervention strategies were slightly effective at improving their child's sleep problem, the use of positive bedtime routines and melatonin treatment were perceived as more effective by parents. These results aid professionals in the selection of future research and intervention strategies to recommend for parents of children with CHARGE syndrome.

Growth in CHARGE syndrome: optimizing care with a multidisciplinary approach

CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital hypoplasia, Ear anomalies including hearing loss) syndrome is a rare syndrome with an incidence of approximately 1:15,000 newborns. It is caused by pathogenic variants in the CHD7 gene and clinically characterized by a wide range of anomalies with variable expression. Growth retardation affects 60-72% of children with CHARGE syndrome, making it one of the most prominent medical issues in the syndrome. Growth retardation in CHARGE syndrome is thought to be multifactorial and can be influenced by almost all co-morbidities, requiring a multidisciplinary approach to the different medical problems. In this systematic review, we describe what is currently known about growth in CHARGE syndrome and how it is influenced by commonly seen clinical problems including feeding difficulties, hypogonadotropic hypogonadism and growth hormone deficiency. Furthermore, we provide recommendations for a multidisciplinary approach.

Identifying pain in children with CHARGE syndrome

Background and aims The objective was to conduct the first investigation to identify the frequency and intensity of pain experiences for individuals with CHARGE syndrome and to review the use of two established non-vocal pain assessments with children with CHARGE, the NCCPC-R (Non-Communicating Children's Pain Checklist-Revised) and the PPP (Pediatrics Pain Profile). Methods Parents of children with CHARGE were enrolled. Participants completed a pain questionnaire and the NCCPC-R and PPP twice, once for a baseline measure and second during a painful experience for their child. Results A moderate negative correlation between the mean intensity of pain and the mean duration of pain among individuals with CHARGE was found, ρ=-0.34. There was a tendency for intensity of pain to increase for sources of pain that were of shorter duration. The NCCPC-R and PPP were found to identify pain when compared to baseline performance (no pain) with a large effect, d=1.3. For the NCCPC-R, the difference between these ratings was significant beyond the 0.05 level, t (40)=8.15, p=0.000, 95% CI [16.93, 28.10]. Similarly, for the PPP, the mean pain ratings were significantly greater than the mean ratings for no pain, with significance beyond the 0.05 level, t (51)=9.59, p=0.000, CI 95% [11.74, 17.96]. Conclusions Evidence exists that children with CHARGE experience pain. While the NCCPC-R and PPP were found to identify pain; future research should consider the development of a pain assessment individualized to pain behaviors present in CHARGE syndrome, given this population's unique expression of pain.

Gastrointestinal and feeding difficulties in CHARGE syndrome: A review from head-to-toe

CHARGE syndrome is an autosomal dominant genetic condition that is primarily diagnosed based on clinical features, with genetic testing available for confirmation. The CHARGE mnemonic stands for some of the common characteristics: coloboma, heart defects, atresia/stenosis of the choanae, retardation of growth/development, genitourinary anomalies, and ear abnormalities (CHARGE). However, many of the common clinical features are not captured by this mnemonic, including cranial nerve dysfunction, considered by some to be one of the major diagnostic criteria. Over 90% of individuals experience feeding and gastrointestinal dysfunction, which carries great morbidity and mortality. The aim of this review is to examine the nature of gastrointestinal (GI) symptoms and feeding difficulties in CHARGE syndrome, focusing on their underlying pathology, associated investigations, and available treatment options. We also provide information on available tools (for parents, clinicians, and researchers) that are important additions to the lifelong healthcare management of every individual with CHARGE syndrome. We review how cranial nerve dysfunction is one of the most important characteristics underlying the pervasive GI and feeding dysfunction, and discuss the need for future research on gut innervation and motility in this genetic disorder.

Behavior in CHARGE syndrome

Unusual behavior is often associated with genetic syndromes, and may constitute a behavioral phenotype. In contrast to providing a psychiatric diagnosis, a behavioral phenotype describes what is unique to the behavior associated with different syndromes. While behaviors in CHARGE are as complex and variable as other aspects of the syndrome, there are some commonalities that raise the question of common sources for these behaviors. This article addresses how pain, sensory issues, and anxiety may impact the behavior of individuals with CHARGE syndrome, and how the development of self-regulation skills might help to mitigate some of the behaviors.

Quality of life in adolescents and adults with CHARGE syndrome

Health-related Quality of Life and the Impact of Childhood Neurologic Disability Scale were collected for 53 patients with CHARGE syndrome aged 13-39 years with a mean academic level of 4th grade. The most prevalent new and ongoing issues included bone health issues, sleep apnea, retinal detachment, anxiety, and aggression. Sleep issues were significantly correlated with anxiety, self-abuse, conduct problems, and autistic-like behaviors. Problems with overall health, behavior, and balance most affected the number of social activities in the individual's life. Sensory impairment most affected relationships with friends. Two contrasting case studies are presented and demonstrate that the quality of life exists on a broad spectrum in CHARGE syndrome, just as its physical features range from mild to very severe. A multitude of factors, including those beyond the physical manifestations, such as anxiety and sleep problems, influence quality of life and are important areas for intervention. © 2016 Wiley Periodicals, Inc.

Packing and Problematic Feeding Behaviors in CHARGE Syndrome: A Qualitative Analysis

OBJECTIVE

To understand packing and problematic feeding behaviors during mealtime in individuals with CHARGE syndrome. Packing, or holding food in one's cheeks without swallowing, is an adverse feeding behavior that has been described in children with autism and Down syndrome, and in those transitioning from tube to oral feeding. It has never been described in detail in CHARGE syndrome, a genetic disorder with a high prevalence of feeding difficulties, tube feeding, and otorhinolaryngological issues.

METHODS

A mixed methods approach used descriptive and qualitative content analysis of interviews with parents of children, adolescents, and adults with CHARGE syndrome. Individuals had previously or were currently experiencing packing or overstuffing one's mouth with food during eating.

RESULTS

Twenty parents completed a phone interview, describing their child/adult's (2-32 years) adverse feeding behaviors. Individuals had a higher proportion of cleft palates (40%) in comparison to the general CHARGE population (15-20%). Parents reported food packing most commonly with bread and pasta (33%), and reported that food was held in cheeks for hours after a meal had ended (35%). Packing was reported to prolong mealtimes for over an hour (30%). Parents were worried about choking during eating (30%). Food packing was also reported in individuals who had never needed G/J tube feeding or feeding therapy, in addition to those who had needed both.

CONCLUSION

This study provides an in-depth description of parents' experiences with packing and adverse feeding behaviors in individuals with CHARGE syndrome. These feeding behaviors are an important addition to the knowledge of the highly prevalent feeding difficulties in this genetic disorder. Individualized evaluation of feeding behavior should be a part of the standard otolaryngologic and feeding team practice for these patients.

Newly Emerging Feeding Difficulties in a 33-Year-Old Adult With CHARGE Syndrome

Feeding and swallowing difficulties are common among individuals with CHARGE syndrome. Many children require gastrostomy tube feeding in their early years and often undergo a delay in feeding and oral-motor skill development. There is little information available on adults with CHARGE syndrome, and the feeding difficulties they face. The present case describes newly emerging mouth over-stuffing feeding behaviors and feeding difficulties in a 33-year-old adult with CHARGE syndrome who had not undergone feeding therapy since childhood.

CHARGE syndrome and Cochlear implantation: difficulties and outcomes in the paediatric population

OBJECTIVES

CHARGE syndrome is a complex cluster of congenital abnormalities, these children may have absent or hypoplastic auditory nerves. Our objective was to assess preoperative factors and outcomes for paediatric cochlear implant recipients with CHARGE syndrome, to enable better surgical preparation and family counselling.

METHODS

The Sydney Cochlear Implant Centre database was searched for children with CHARGE syndrome who had received a cochlear implant at ages 16 and less. Data were collected regarding clinical history; hearing assessments; MRI and CT scan findings; preoperative transtympanic electrical Auditory Brainstem Response (ABR); intraoperative findings and intraoperative electrical ABR and Neural Response Telemetry; and language outcomes in terms of main language used and Categories of Auditory Performance scores (0-7 ranking).

RESULTS

Ten children were identified. All seven prelingual profoundly deaf children with CHARGE syndrome had hypoplastic or absent auditory nerves bilaterally on MRI scans. Middle ear anatomy was often abnormal, affecting surgical landmarks and making identification of the cochlea very difficult in some cases. Three cases required repeated surgery to obtain successful cochlear implant insertion, one under CT scan image guided technique. All seven children used sign language, or simpler gestures, as their main mode of communication. Two children of of these children, who were implanted early, also attained some spoken language. CAP scores ranged from 0 to 6. The three children with CHARGE syndrome and progressive sensorineural hearing loss had a normal auditory nerve in at least one ear on MRI scans. All had preoperative verbal language, with CAP scores of 6, and continued with CAP scores of 6 following receipt of the cochlear implant.

CONCLUSION

Children with CHARGE and congenital profound hearing loss all had hypoplasia or absent auditory nerves, affecting their outcomes with cochlear implants. They often had markedly abnormal middle ear anatomy and CT image guided surgery can be helpful. These children should be offered a bilingual early intervention approach, using sign language and verbal language, to ensure best language outcomes. Children with CHARGE syndrome and progressive profound hearing loss did well with cochlear implants and continue to be able to use verbal language.

Obstructive Sleep Apnea in a Patient with CHARGE Syndrome

CHARGE syndrome is a genetic disorder characterized by choanal atresia, coloboma of the eye, and ear and cranial nerve abnormalities. We report a child with CHARGE syndrome and obstructive sleep apnea. We highlight difficulties in discerning obstructive sleep apnea-related symptoms from typical features of CHARGE syndrome. Treatment options are discussed with regard to our patient. Tonsillectomy and adenoidectomy improved physical symptoms of obstructive sleep apnea in the patient.

Development and characteristics of children with Usher syndrome and CHARGE syndrome

OBJECTIVE

Individuals with Usher syndrome or CHARGE syndrome are faced with a number of difficulties concerning hearing, vision, balance, and language development. The aim of the study is to describe the developmental characteristics of children with Usher syndrome and CHARGE syndrome, respectively.

METHOD

Data about the developmental characteristics of 26 children with Usher syndrome and 17 children with CHARGE syndrome was obtained. Associations between deafblindness (dual sensory loss), motor development (age of walking), language abilities, and intellectual outcome of these children were explored for each group independently.

RESULTS

Both groups of children face a number of difficulties associated with vision, hearing, language, balance and intellectual outcome. Intellectual disability and/or language delay was found among 42% of the children with Usher syndrome and among 82% of the children with CHARGE syndrome. Intellectual disability was associated with language delay and age of walking for both groups.

CONCLUSIONS

Even though Usher and CHARGE are two different genetic syndromes, both groups are challenged with a number of similar developmental delays. Clinicians need to be aware of several developmental issues in order to offer adequate support to children with Usher or CHARGE syndrome.

Understanding obstructive sleep apnea in children with CHARGE syndrome

OBJECTIVE

CHARGE syndrome occurs in approximately 1 in 8500 live births and is diagnosed clinically by combinations of major characteristics: choanal atresia, coloboma, characteristic ears, cranial nerve abnormalities and distinct temporal bone anomalies. More than 50% of children with CHARGE syndrome experience sleep disturbances, with obstructive sleep apnea being one diagnosis. Objectives of this study were to develop a better understanding of the prevalence, symptomatology and treatments of sleep apnea in CHARGE syndrome. Secondary aims were to determine the usefulness of questionnaires examining obstructive sleep apnea in a CHARGE syndrome population.

METHODS

Parents of 51 children with CHARGE syndrome (aged 0-14 years) were recruited between May 2010 and July 2011. Genetic testing and/or clinical criteria confirmed diagnosis of CHARGE syndrome. Questionnaires completed by parents included one covering CHARGE characteristics and three previously validated questionnaires: the Brouilette Score Questionnaire, the Pediatric Sleep Questionnaire and the OSA-18 Quality of Life Questionnaire. SPSS 19.0 was used for statistical calculations.

RESULTS

Previous diagnosis of obstructive sleep apnea was present in 65% of the study population. Treatments included continuous positive airway pressure, tonsillectomy and/or adenoidectomy, and tracheostomy. Brouilette scores identified the presence of obstructive sleep apnea in the CHARGE syndrome population studied and indicated statistically significant (p=<0.001) improvements following treatment, which were comparable to the general population. Only the subscales of snoring and daytime sleepiness were useful in identifying obstructive sleep apnea using the Pediatric Sleep Questionnaire. The OSA-18 Questionnaire indicated that residual symptoms affecting quality of life may be present in the CHARGE syndrome population after treatment for obstructive sleep apnea.

CONCLUSIONS

Obstructive sleep apnea appears to be prevalent in children with CHARGE syndrome. All conventional treatments for obstructive sleep apnea reduce symptomatology. Brouilette scores are useful in identifying obstructive sleep apnea in the CHARGE syndrome population. The Pediatric Sleep Questionnaire could be useful once modified. The OSA-18 Questionnaire would be most useful as a means to measure quality of life gains following treatment.

Anosmia predicts hypogonadotropic hypogonadism in CHARGE syndrome

OBJECTIVE

To test the hypothesis that a smell test could predict the occurrence of hypogonadotropic hypogonadism (HH) in patients with CHARGE syndrome, which is a variable combination of ocular coloboma, heart defects, choanal atresia, retardation of growth/development, genital hypoplasia, and ear anomalies or hearing loss caused by mutations in the CHD7 (chromodomain helicase DNA binding protein 7) gene.

STUDY DESIGN

We performed endocrine studies and smell testing (University of Pennsylvania Smell Identification Test) in 35 adolescent patients with molecularly confirmed CHARGE syndrome.

RESULTS

Complete data on smell and puberty were available for 15 patients; 11 patients had both anosmia and HH, whereas 4 patients had normosmia/hyposmia and spontaneous puberty. In addition, 7 boys were highly suspected of having HH (they were too young for definite HH diagnosis, but all had cryptorchidism, micropenis, or both) and had anosmia. The type of CHD7 mutation could not predict HH because a father and daughter with the same CHD7 mutation were discordant for HH and anosmia.

CONCLUSION

Anosmia and HH were highly correlated in our cohort, and therefore smell testing seems to be an attractive method for predicting the occurrence of HH in patients with CHARGE syndrome. The use of this test could prevent delay of hormonal pubertal induction, resulting in an age-appropriate puberty.

Parenting Stress in CHARGE Syndrome and the Relationship with Child Characteristics

This study investigates the parental perception of stress related to the upbringing of children with CHARGE syndrome and its association with behavioral and physical child characteristics. Parents of 22 children completed the Nijmegen Parenting Stress Index-Short, Developmental Behavior Checklist, and Dutch Vineland Screener 0-12 and reported their child's problems with hearing, vision and ability to speak. Parenting stress was high in 59% of the subjects. Behavioral problems on the depression, autism, self-absorbed and disruptive behavior scales correlated positively with parenting stress. A non-significant trend was found, namely higher stress among the parents of non-speaking children. No associations were found with other child characteristics, i.e. level of adaptive functioning and intellectual disability, auditory and visual problems, deafblindness, gender, and age. Raising a child with CHARGE syndrome is stressful; professional support is therefore essential for this population. More research into other possible influencing characteristics is needed to improve family-oriented interventions. Since CHARGE is a rare syndrome, closer international collaboration is needed, not only to expand the group of study subjects to increase statistical power, but also to harmonize research designs and measurement methods to improve the validity, the reliability, and the generalization of the findings.

Sleep disturbances in CHARGE syndrome: types and relationships with behavior and caregiver well-being

Children with CHARGE syndrome frequently develop moderate to severe behavior difficulties and are often diagnosed with obsessive-compulsive disorder, attention deficit disorder, Tourette syndrome, and autism. Anecdotal reports have indicated that sleep is also affected. However, the prevalence and types of sleep disturbance have not been identified. This study investigated sleep disturbances in 87 children with CHARGE syndrome, aged 6 to 18 years (mean 11y, SD 3y 8mo). There were 52 males and 35 females represented. Instruments included measures of sleep (Sleep Disturbances Scale for Children [SDSC]), behavior (Developmental Behaviour Checklist [DBC]), and carer well-being (Malaise Inventory). On the SDSC, 57.5% received scores considered significant for sleep disturbances, with disorders of initiating and maintaining sleep, sleep breathing, and sleep-wake transition being the most common. The SDSC was significantly correlated with the DBC (p=0.010) and the Malaise Inventory (p=0.003). Regression analysis found that both problem behavior and sleep disturbances contributed to the prediction of scores on the Malaise Inventory. Being both deaf and blind (p=0.001), experiencing frequent middle-ear infections (p=0.015), and starting to walk at an older age (p=0.007) were associated with more sleep disturbance. Craniofacial anomalies were not. The study highlights the importance of addressing the sleep difficulties associated with CHARGE syndrome relating both to airway management and to disorders of initiating sleep.

Postoperative airway events of individuals with CHARGE syndrome

OBJECTIVE

CHARGE syndrome is a heterogeneous genetic disorder comprising multiple congenital anomalies. Major clinical diagnostic criteria include ocular coloboma, choanal atresia/stenosis, characteristic ear abnormalities, and cranial nerve abnormalities. CHARGE syndrome is caused by a mutation in the gene CHD7 located on chromosome 8. Patients with CHARGE syndrome require multiple anesthetics for surgical and otorhinolaryngology procedures. This study describes the postoperative anesthetic related airway events (i.e. re-intubations for apneas and desaturations, airway obstruction due to excessive secretions) of nine individuals with CHARGE syndrome.

METHODS

Detailed chart audits were performed on nine patients diagnosed clinically with CHARGE syndrome who had undergone surgery at a single tertiary health centre. The CHARGE characteristics present in each individual, the number and types of surgeries and anesthetics, and the related postoperative airway events were determined.

RESULTS

The mean+/-age of the population at chart review was 11.8 years (+/-8.0). The total number of anesthetics was 147, with a mean of 16.2(+/-8.4). Of the 215 surgical procedures (mean 21.9, +/-12.2), 30% were otorhinolaryngological. Postoperative airway events occurred after 35% of anesthetics. Surgeries resulting in the most airway events involved the heart (65%), the gastrointestinal tract (39%), and airway diagnostic scopes, i.e., bronchoscopy, laryngoscopy, and nasopharyngoscopy (36%). Combining multiple surgical procedures under one anesthetic did not increase the risk of postoperative airway events. As individuals aged, they had fewer surgeries and anesthetics, as well as a lower risk of postoperative airway events.

CONCLUSION

Individuals with CHARGE syndrome face a significant risk of postoperative airway events with anesthesia, and this is exacerbated by the high number of surgeries they require. Surgeons and anesthesiologists should be aware of potential for postoperative airway events in individuals with CHARGE syndrome and plan accordingly.

Mutations in CHD7, encoding a chromatin-remodeling protein, cause idiopathic hypogonadotropic hypogonadism and Kallmann syndrome

CHARGE syndrome and Kallmann syndrome (KS) are two distinct developmental disorders sharing overlapping features of impaired olfaction and hypogonadism. KS is a genetically heterogeneous disorder consisting of idiopathic hypogonadotropic hypogonadism (IHH) and anosmia, and is most commonly due to KAL1 or FGFR1 mutations. CHARGE syndrome, a multisystem autosomal-dominant disorder, is caused by CHD7 mutations. We hypothesized that CHD7 would be involved in the pathogenesis of IHH and KS (IHH/KS) without the CHARGE phenotype and that IHH/KS represents a milder allelic variant of CHARGE syndrome. Mutation screening of the 37 protein-coding exons of CHD7 was performed in 101 IHH/KS patients without a CHARGE phenotype. In an additional 96 IHH/KS patients, exons 6-10, encoding the conserved chromodomains, were sequenced. RT-PCR, SIFT, protein-structure analysis, and in situ hybridization were performed for additional supportive evidence. Seven heterozygous mutations, two splice and five missense, which were absent in > or = 180 controls, were identified in three sporadic KS and four sporadic normosmic IHH patients. Three mutations affect chromodomains critical for proper CHD7 function in chromatin remodeling and transcriptional regulation, whereas the other four affect conserved residues, suggesting that they are deleterious. CHD7's role is further corroborated by specific expression in IHH/KS-relevant tissues and appropriate developmental expression. Sporadic CHD7 mutations occur in 6% of IHH/KS patients. CHD7 represents the first identified chromatin-remodeling protein with a role in human puberty and the second gene to cause both normosmic IHH and KS in humans. Our findings indicate that both normosmic IHH and KS are mild allelic variants of CHARGE syndrome and are caused by CHD7 mutations.

Risk factors for poor bone health in adolescents and adults with CHARGE syndrome

CHARGE syndrome, is associated with genital hypoplasia, feeding difficulties and delayed puberty. In this study we examined the prevalence of risk factors for poor bone health in adolescents and adults with CHARGE. Questionnaires assessing fracture history, dietary intake of calcium and vitamin D, pubertal status and activity level using the Habitual Activity Estimation Scale (HAES) were completed by caregivers. Control data were collected for the HAES. When available, reports from dual-energy X-ray absorptiometry (DEXA) were obtained. Thirty individuals with CHARGE syndrome (n = 15 males; n = 15 females; age range 13 to 34 years; mean age 19.6 years) were recruited. Traumatic bony fractures were identified in 30% of the population. The recommended nutritional intake (RNI) for calcium and vitamin D were not met by 41% and 87% of the population, respectively, and 53% required past tube feeding. Delayed puberty was experienced by 87% with only 4 individuals (2 female, 2 males) having experienced normal puberty. Hormone replacement therapy (HRT) was taken by 33% of females and 60% of males. According to the HAES, adolescents with CHARGE syndrome (13-18 years) were significantly less active than controls. Individuals with CHARGE syndrome age 19 and older were also less active than controls, although this difference was not significant. DEXA scan data was obtained, however, due to small sample size (n = 10) and confounding variables (i.e., short stature, pubertal stage, height, weight), it was difficult to draw meaningful conclusions. Feeding difficulties, inactivity and hypogonadism are predisposing factors for the development of poor bone health among individuals with CHARGE syndrome. Education is necessary to raise awareness regarding the importance of HRT, proper nutrition and weight-bearing activity for healthy bone development and maintenance in individuals with CHARGE syndrome.

CHARGE syndrome: an update

CHARGE syndrome is a rare, usually sporadic autosomal dominant disorder due in 2/3 of cases to mutations within the CHD7 gene. The clinical definition has evolved with time. The 3C triad (Coloboma-Choanal atresia-abnormal semicircular Canals), arhinencephaly and rhombencephalic dysfunctions are now considered the most important and constant clues to the diagnosis. We will discuss here recent aspects of the phenotypic delineation of CHARGE syndrome and highlight the role of CHD7 in its pathogeny. We review available data on its molecular pathology as well as cytogenetic and molecular evidences for genetic heterogeneity within CHARGE syndrome.

CHARGE syndrome

CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies/deafness). In 1998, an expert group defined the major (the classical 4C's: Choanal atresia, Coloboma, Characteristic ears and Cranial nerve anomalies) and minor criteria of CHARGE syndrome. Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome. However, there have been individuals genetically identified with CHARGE syndrome without the classical choanal atresia and coloboma. The reported incidence of CHARGE syndrome ranges from 0.1-1.2/10,000 and depends on professional recognition. Coloboma mainly affects the retina. Major and minor congenital heart defects (the commonest cyanotic heart defect is tetralogy of Fallot) occur in 75-80% of patients. Choanal atresia may be membranous or bony; bilateral or unilateral. Mental retardation is variable with intelligence quotients (IQ) ranging from normal to profound retardation. Under-development of the external genitalia is a common finding in males but it is less apparent in females. Ear abnormalities include a classical finding of unusually shaped ears and hearing loss (conductive and/or nerve deafness that ranges from mild to severe deafness). Multiple cranial nerve dysfunctions are common. A behavioral phenotype for CHARGE syndrome is emerging. Mutations in the CHD7 gene (member of the chromodomain helicase DNA protein family) are detected in over 75% of patients with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management as well as numerous surgical interventions. They also need multidisciplinary follow up. Some of the hidden issues of CHARGE syndrome are often forgotten, one being the feeding adaptation of these children, which needs an early aggressive approach from a feeding team. As the child develops, challenging behaviors become more common and require adaptation of educational and therapeutic services, including behavioral and pharmacological interventions.

Phenotypic spectrum of CHARGE syndrome in fetuses with CHD7 truncating mutations correlates with expression during human development

BACKGROUND

The acronym CHARGE refers to a non-random cluster of malformations including coloboma, heart malformation, choanal atresia, retardation of growth and/or development, genital anomalies, and ear anomalies. This set of multiple congenital anomalies is frequent, despite rare patients with normal intelligence, and prognosis remains poor. Recently, CHD7 gene mutations have been identified in CHARGE patients; however, the function of CHD7 during development remains unknown.

METHODS

We studied a series of 10 antenatal cases in whom the diagnosis of CHARGE syndrome was suspected, considering that a careful pathological description would shed light on the CHD7 function during development. CHD7 sequence analysis and in situ hybridisation were employed.

RESULTS

The diagnosis of CHARGE syndrome was confirmed in all 10 fetuses by the identification of a CHD7 heterozygous truncating mutation. Interestingly, arhinencephaly and semi-circular canal agenesis were two constant features which are not included in formal diagnostic criteria so far. In situ hybridisation analysis of the CHD7 gene during early human development emphasised the role of CHD7 in the development of the central nervous system, internal ear, and neural crest of pharyngeal arches, and more generally showed a good correlation between specific CHD7 expression pattern and the developmental anomalies observed in CHARGE syndrome.

CONCLUSIONS

These results allowed us to further refine the phenotypic spectrum of developmental anomalies resulting from CHD7 dysfunction.