Translational Research and Clinical Implications Regarding Communication Outcomes in Neurogenetic Disorders

Neurogenetic disorders are a heterogeneous group of known genetic disorders.[1] [2] These genetic mutations, additions, and/or deletions affect brain development, resulting in a cascading effect on other domains of development (i.e., cognition, language, social and emotional skills, and behavior). Each neurogenetic disorder is associated with a syndrome-specific pattern of behavior referred to as a behavioral phenotype.[3] [4] A behavioral phenotype is defined as “the heightened probability or likelihood that people with a given syndrome will exhibit certain behavioral or developmental sequelae relative to those without the syndrome.”[3] ^(p.523) Although this means that certain behaviors and developmental characteristics are more common to many people with the disorder, not all individuals will display these features. Furthermore, not all of these features are completely unique to the disorder.[3] [5] [6] [7] One common feature across individuals with neurogenetic disorders is the presence of intellectual disability, with more than 1,300 genes associated with intellectual disability.[2] [8] [9] Importantly, neurogenetic disorders can be diagnosed early in development (i.e., pre-, peri-, or postnatally), providing early opportunities for intervention. Because many children with neurogenetic disorders also have language and communication disorders, they begin to receive speech-language pathology services starting at an early age. Furthermore, these difficulties with language and communication can be lifelong, requiring intervention and support for successful participation and independence.

In this special issue of Seminars in Speech and Language, we provide readers with translational research about two common neurogenetic disorders, Down syndrome and fragile X syndrome, including clinical implications that can support current treatment efforts. We focused on these two neurogenetic disorders due to their prevalence, their associated language and communication disorders, and the recent increase in research efforts to support these individuals (e.g., NIH Down syndrome Research Plan, NIH Fragile X Research Plan). Also, Down syndrome is the leading genetic cause of intellectual disability, and fragile X syndrome is the leading inherited cause of intellectual disability.

As is now the standard, family-centered intervention services are key for supporting early development in children with neurogenetic disorders. Given the inherited nature of fragile X syndrome, the article in this issue by Bangert, Moser, Friedman, and Klusek provides a discussion of how mothers of children with fragile X syndrome, who are genetic carriers, present with their own unique language and cognitive characteristics that may impact their children's language outcomes. This is an important consideration, especially with the rise of parent-implemented language interventions for children with neurogenetic disorders. In fact, in the past 6 years, there has been an increase in responsive parenting interventions for children with fragile X syndrome. Bullard and Abbeduto summarize the current research on these responsive parenting interventions and discuss how the use of telehealth procedures can bridge the research-to-practice gap.

Building on the importance of responsive parenting for language development of children with neurogenetic disorders, Mattie and Hadley identify the linguistic, conceptual, and interactive features of high-quality maternal language input. In doing so, they provide clinicians with a new way to examine and enrich caregiver input to promote word learning for children with neurogenetic disorders. Echoing the important role of caregivers in language development, Channell and Bosley describe mental state language use by children with Down syndrome and the active role caregivers play in the acquisition of these skills. In addition to summarizing ways to assess and provide intervention for mental state language use in this population, they provide an important reminder to clinicians that common intervention strategies such as shared book reading may continue to be appropriate contexts for children with neurogenetic disorders at later chronological ages. A similar approach is also needed for supporting reading development in Down syndrome (i.e., using abilities instead of chronological age to determine intervention targets). Although the ability to read is a key concern expressed by parents, Loveall and Barton-Hulsey highlight the limited evidence base in this area. Nonetheless, they provide clinicians with a road map for using Chall's[10] stage-based theory of reading development for supporting youth with Down syndrome. Lastly, Barton-Hulsey, Phinney, and Collins summarize the utility of augmentative and alternative communication in supporting language and literacy interventions for children with Down syndrome or autism spectrum disorders.

Together, the articles in this issue highlight the shifting focus of research on children with neurogenetic disorders from basic descriptions toward translational and intervention research. One common theme across these articles is the inclusion of recommendations and considerations for how clinicians can best support their clients with neurogenetic disorders. It is my sincere hope that clinicians who read these articles will know that, as researchers, we want to support them and their clients. It is critical to promote continued efforts to break down the research and clinical silos—efforts that will lead to more collaborations that support children with neurogenetic disorders and their families.

Financial

No relevant relationships exist for the author.

Nonfinancial

No relevant relationships exist for the author.

Publication History

Article published online:
26 July 2021

• References

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