Influence of hearing loss and cognitive abilities on language development in CHARGE 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.

To speak may draw on epigenetic writing and reading: Unravelling the complexity of speech and language outcomes across chromatin-related neurodevelopmental disorders

Speech and language development are complex neurodevelopmental processes that are incompletely understood, yet current evidence suggests that speech and language disorders are prominent in those with disorders of chromatin regulation. This review aimed to unravel what is known about speech and language outcomes for individuals with chromatin-related neurodevelopmental disorders. A systematic literature search following PRISMA guidelines was conducted on 70 chromatin genes, to identify reports of speech/language outcomes across studies, including clinical reports, formal subjective measures, and standardised/objective measures. 3932 studies were identified and screened and 112 were systematically reviewed. Communication impairment was core across chromatin disorders, and specifically, chromatin writers and readers appear to play an important role in motor speech development. Identification of these relationships is important because chromatin disorders show promise as therapeutic targets due to the capacity for epigenetic modification. Further research is required using standardised and formal assessments to understand the nuanced speech/language profiles associated with variants in each gene, and the influence of chromatin dysregulation on the neurobiology of speech and language development.

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.

Frühe Prädiktoren der Sprachentwicklung von Kindern mit permanenter Hörstörung

Zusammenfassung. Theoretischer Hintergrund: Sprachentwicklungsverläufe bei Kindern mit Hörstörungen zeigen eine hohe und überwiegend ungeklärte Varianz. Fragestellung und Methode: Unsere Übersichtsarbeit präsentiert aktuelle Evidenz zu frühen Prädiktoren der Sprachentwicklung. Ergebnisse und Diskussion: Trotz deutlicher positiver Trends erreicht nur jedes zweite Kind ein Sprachentwicklungsniveau im Normbereich. Der Literaturüberblick ergibt signifikante kindbezogene und familiäre Prädiktoren mit eher geringer Beeinflussbarkeit. Als hoch prädiktiv für sprachliche Ergebnisse und zudem der Intervention zugänglich erweisen sich die frühe Erkennung und technische Versorgung mit Hörgeräten oder -implantaten und Aufnahme in die Frühförderung, konsistente Hörtechnikverwendung und/oder früher Zugang zur Gebärdensprache. Zudem zeigt sich die Qualität der täglichen Eltern-Kind-Interaktion als hocheffektiv für die Sprachentwicklung. Schlussfolgerung: Es bestätigt sich die Wirksamkeit aktueller Best Practice früher Erkennung, Versorgung und familienzentrierter Frühförderung.

Auditory Skills following Cochlear Implantation in Children with the Charge Syndrome

OBJECTIVES

To assess the auditory outcomes and skills of pediatric cochlear implant (CI) users with the CHARGE syndrome. To determine the influence of inner ear malformations on the surgical procedure and speech understanding outcomes in this population.

STUDY DESIGN

Observational, retrospective study.

MATERIALS AND METHODS

Imaging, auditory testing, intraoperative findings, complications, and postoperative auditory skills and outcomes of pediatric CI users with CHARGE syndrome were recorded.

RESULTS

6 children (8 ears) were included, 5 of whom had prelingual deafness. Their mean age at implantation was 37 months. Six of the 8 ears presented cochlear malformation; the most frequent was hypoplasia type III. Intraoperatively, the transmastoid facial recess approach was used in 5 ears, and abnormalities of facial nerve anatomy were found in 5 ears. All electrode insertions were complete. All children were, to a varying degree, able to detect and identify sound. Verbalization skills were developed by 2 children, 1 of whom used oral language as his primary mode of communication.

CONCLUSIONS

Cochlear implantation performed by an experienced surgeon in patients with the CHARGE syndrome is a safe procedure with adequate treatment planning. All children had improved auditory skills although the improvement was variable.

Evaluation and management of syndromic congenital hearing loss

PURPOSE OF REVIEW

The purpose of this review is to review the evaluation and management of children with syndromic hearing loss. Specific syndromes and the impact of those syndromes on managing hearing loss will be discussed.

RECENT FINDINGS

Improved molecular testing has increased the ability to identify syndromes-associated hearing loss. Accurate diagnosis of syndromic hearing loss can guide discussions regarding prognosis and appropriate management options for the hearing impairment.

SUMMARY

A significant portion of childhood hearing loss is associated with a syndrome. Depending on the syndrome, surgical intervention including a bone-anchored hearing aid or cochlear implant may be helpful. In the future, targeted gene therapies may become a viable option for treating syndromic hearing loss.

Distinct cerebellar foliation anomalies in a CHD7 haploinsufficient mouse model of CHARGE syndrome

Mutations in the gene encoding the ATP dependent chromatin‐remodeling factor, CHD7 are the major cause of CHARGE (Coloboma, Heart defects, Atresia of the choanae, Retarded growth and development, Genital‐urinary anomalies, and Ear defects) syndrome. Neurodevelopmental defects and a range of neurological signs have been identified in individuals with CHARGE syndrome, including developmental delay, lack of coordination, intellectual disability, and autistic traits. We previously identified cerebellar vermis hypoplasia and abnormal cerebellar foliation in individuals with CHARGE syndrome. Here, we report mild cerebellar hypoplasia and distinct cerebellar foliation anomalies in a Chd7 haploinsufficient mouse model. We describe specific alterations in the precise spatio‐temporal sequence of fissure formation during perinatal cerebellar development responsible for these foliation anomalies. The altered cerebellar foliation pattern in Chd7 haploinsufficient mice show some similarities to those reported in mice with altered Engrailed, Fgf8 or Zic1 gene expression and we propose that mutations or polymorphisms in these genes may modify the cerebellar phenotype in CHARGE syndrome. Our findings in a mouse model of CHARGE syndrome indicate that a careful analysis of cerebellar foliation may be warranted in patients with CHARGE syndrome, particularly in patients with cerebellar hypoplasia and developmental delay.

Inner ear manifestations in CHARGE: Abnormalities, treatments, animal models, and progress toward treatments in auditory and vestibular structures

The inner ear contains the sensory organs for hearing and balance. Both hearing and balance are commonly affected in individuals with CHARGE syndrome (CS), an autosomal dominant condition caused by heterozygous pathogenic variants in the CHD7 gene. Semicircular canal dysplasia or aplasia is the single most prevalent feature in individuals with CHARGE leading to deficient gross motor skills and ambulation. Identification of CHD7 as the major gene affected in CHARGE has enabled acceleration of research in this field. Great progress has been made in understanding the role of CHD7 in the development and function of the inner ear, as well as in related organs such as the middle ear and auditory and vestibular neural pathways. The goals of current research on CHD7 and CS are to (a) improve our understanding of the pathology caused by CHD7 pathogenic variants and (b) to provide better tools for prognosis and treatment. Current studies utilize cells and whole animals, from flies to mammals. The mouse is an excellent model for exploring mechanisms of Chd7 function in the ear, given the evolutionary conservation of ear structure, function, Chd7 expression, and similarity of mutant phenotypes between mice and humans. Newly recognized developmental functions for mouse Chd7 are shedding light on how abnormalities in CHD7 might lead to CS symptoms in humans. Here we review known human inner ear phenotypes associated with CHD7 pathogenic variants and CS, summarize progress toward diagnosis and treatment of inner ear-related pathologies, and explore new avenues for treatment based on basic science discoveries.