Genetic testing in intellectual disability psychiatry: Opinions and practices of UK child and intellectual disability psychiatrists

Do we care? Reporting of genetic diagnoses in multidisciplinary intellectual disability care: a retrospective chart review

BACKGROUND

Advances in understanding the etiology of intellectual disability (ID) has led to insights in potential (targeted) treatments and personalized care. Implications of ID on health are often complex and require a multidisciplinary approach. The aim was to investigate the reporting of genetic diagnoses in multidisciplinary ID care and to identify associated clinical and demographic factors.

METHODS

A retrospective chart review was performed on a randomly selected sample of individuals (n = 380) of a large ID care organization in the Netherlands. Data on genetic etiology, including genetic testing and diagnoses, and clinical and demographic characteristics were collected from files held by multidisciplinary team members.

RESULTS

Reports on genetic etiology were available in 40% of the study sample (n = 151), with a genetic diagnosis recorded in 34% (n = 51), which is 13% of the total sample. In those with reported genetic diagnoses, this was reported in 90% of medical, 39% of psychodiagnostic, and 75% of professional caregivers' files. Older age, mild ID, and the legal representative not being a family member were associated with less reported information on genetic etiology.

CONCLUSIONS

This study revealed that genetic diagnoses were often not reported in ID care files. Recommendations were formulated to reduce delay in diagnosis, and enable personalized care for individuals with ID.

Genetics of Attention-Deficit Hyperactivity Disorder

Attention-Deficit Hyperactivity Disorder (ADHD) has long been recognized as being a highly heritable condition and our understanding of the genetic contributions to ADHD has grown over the past few decades. This chapter will discuss the studies that have examined its heritability and the efforts to identify specific genetic risk-variants at the molecular genetic level. We outline the various techniques that have been used to characterize genetic contributions to ADHD, describing what we have learnt so far, what there is still to learn and the methodologies that can be used to further our knowledge. In doing so we will discuss research into rare and common genetic variants, polygenic risk scores, and gene-environment interplay, while also describing what genetic studies have revealed about the biological processes involved in ADHD and what they have taught us about the overlap between ADHD and other psychiatric and somatic disorders. Finally, we will discuss the strengths and limitations of the current methodologies and clinical implications of genetic research to date.

Genetic Testing on Patients with Developmental Delay: A Preliminary Study from the Perspective of Physicians

This study aimed to discover and propose solutions to various decision-making problems, including obtaining consent, encountered by physicians when administering genetic testing to patients with disabilities. A preliminary survey and focus group interviews (FGIs) were conducted with 27 specialists who had 5–25 years of clinical experience in rehabilitation medicine, pediatrics, and obstetrics and gynecology, regarding their experience in providing genetic testing to people with developmental disabilities. This included the “role of medical staff in the patient’s decision-making process”, “difficulty of the consent process for genetic testing”, and so forth. Some limitations were identified in the genetic testing communication process for patients with disabilities. Although providing information corresponding to the level of understanding of each person and accurately evaluating the correct consenting ability is important, the usage rate of auxiliary tools, such as booklets and videos, was only 50.0%. Additionally, there were concerns regarding the marriage prospects of people with disabilities. For people with developmental disabilities to provide consent for genetic testing, legal consent forms and explanation aids that consider individual characteristics are necessary. Moreover, education on disability awareness throughout society, including cost support, is needed.

Challenges and opportunities for integrating genetic testing into a diagnostic workflow: heritable long QT syndrome as a model

BACKGROUND

An increasing number of diagnostic evaluations incorporate genetic testing to facilitate accurate and timely diagnoses. The increasing number and complexity of genetic tests continue to pose challenges in deciding when to test, selecting the correct test(s), and using results to inform medical diagnoses, especially for medical professionals lacking genetic expertise. Careful consideration of a diagnostic workflow can be helpful in understanding the appropriate uses of genetic testing within a broader diagnostic workup.

CONTENT

The diagnosis of long QT syndrome (LQTS), a life-threatening cardiac arrhythmia, provides an example for this approach. Electrocardiography is the preferred means for diagnosing LQTS but can be uninformative for some patients due to the variable presentation of the condition. Family history and genetic testing can augment physiological testing to inform a diagnosis and subsequent therapy. Clinical and laboratory professionals informed by peer- reviewed literature and professional recommendations constructed a generalized LQTS diagnostic workflow. This workflow served to explore decisions regarding the use of genetic testing for diagnosing LQTS.

SUMMARY AND OUTLOOK

Understanding the complexities and approaches to integrating genetic testing into a broader diagnostic evaluation is anticipated to support appropriate test utilization, optimize diagnostic evaluation, and facilitate a multidisciplinary approach essential for achieving accurate and timely diagnoses.

Genetic Testing in Neurodevelopmental Disorders

Neurodevelopmental disorders are the most prevalent chronic medical conditions encountered in pediatric primary care. In addition to identifying appropriate descriptive diagnoses and guiding families to evidence-based treatments and supports, comprehensive care for individuals with neurodevelopmental disorders includes a search for an underlying etiologic diagnosis, primarily through a genetic evaluation. Identification of an underlying genetic etiology can inform prognosis, clarify recurrence risk, shape clinical management, and direct patients and families to condition-specific resources and supports. Here we review the utility of genetic testing in patients with neurodevelopmental disorders and describe the three major testing modalities and their yields - chromosomal microarray, exome sequencing (with/without copy number variant calling), and FMR1 CGG repeat analysis for fragile X syndrome. Given the diagnostic yield of genetic testing and the potential for clinical and personal utility, there is consensus that genetic testing should be offered to all patients with global developmental delay, intellectual disability, and/or autism spectrum disorder. Despite this recommendation, data suggest that a minority of children with autism spectrum disorder and intellectual disability have undergone genetic testing. To address this gap in care, we describe a structured but flexible approach to facilitate integration of genetic testing into clinical practice across pediatric specialties and discuss future considerations for genetic testing in neurodevelopmental disorders to prepare pediatric providers to care for patients with such diagnoses today and tomorrow.

The composition and capacity of the clinical genetics workforce in high-income countries: a scoping review

As genetics becomes increasingly integrated into all areas of health care and the use of complex genetic tests continues to grow, the clinical genetics workforce will likely face greatly increased demand for its services. To inform strategic planning by health-care systems to prepare to meet this future demand, we performed a scoping review of the genetics workforce in high-income countries, summarizing all available evidence on its composition and capacity published between 2010 and 2019. Five databases (MEDLINE, Embase, PAIS, CINAHL, and Web of Science) and gray literature sources were searched, resulting in 162 unique studies being included in the review. The evidence presented includes the composition and size of the workforce, the scope of practice for genetics and nongenetics specialists, the time required to perform genetics-related tasks, case loads of genetics providers, and opportunities to increase efficiency and capacity. Our results indicate that there is currently a shortage of genetics providers and that there is a lack of consensus about the appropriate boundaries between the scopes of practice for genetics and nongenetics providers. Moreover, the results point to strategies that may be used to increase productivity and efficiency, including alternative service delivery models, streamlining processes, and the automation of tasks.

Parent perceptions, beliefs, and fears around genetic treatments and cures for children with Angelman syndrome

Genetic therapies have shown recent promise in alleviating some of the cognitive issues associated with some genetic disorders; however, these therapies may come with significant health and socio-ethical concerns, particularly when they involve child participants. Little is known about what parents of children with genetic disorders think about genetic therapies, or about their knowledge of how genetic-based therapy might treat their child's symptoms. Forty-two parents of children with Angelman syndrome (AS) and 27 parents of a mixed etiology comparison group completed an online survey reporting on their perceptions of, and priorities for, genetic therapy. Almost all parents of children with AS (95%) and the comparison group (89%) agreed that treatments aiming to reduce symptoms associated with their child's syndrome were positive. However, significantly more parents of children with AS (95%) than the comparison group (56%) felt that genetic treatment trials aiming to "cure" their child should be a research priority. AS parent priorities for the focus of clinical trials were neurology/seizures, communication skills, and motor skills/mobility. For the comparison group, the priorities were IQ, immune response, and expressive speech. Parents of both groups did not want treatments to change their child's personality or their happiness. Global assumptions cannot be made about targets for therapy between syndromes, about parental understanding of genetics, or about research evidence across syndromes. This study highlights the need for true family and patient engagement in all stages of the research design and treatment evaluation.

Improving access to genetic testing for adults with intellectual disability: A literature review and lessons from a quality improvement project in East London

Recent advances in genetic research have led to an increased focus on genetic causes of intellectual disability (ID) and have raised new questions about how and when clinicians offer genetic testing and the nature of communication around this decision with patients and carers. Determining the right approach to such discussions is complicated by complexities of communication, consent, and capacity and ethical concerns about genetic testing in this population. In this article, we briefly discuss the recent advances in genetic research relevant to people with intellectual disability, highlighting the challenges that might arise when undertaking genetic testing in this population. We then describe how we have used a Quality Improvement methodology to develop a clinical pathway for routine genetic testing for adults with intellectual disability in a clinical setting in East London.

Process evaluation of a randomised controlled trial of PBS-based staff training for challenging behaviour in adults with intellectual disability

BACKGROUND

Positive Behaviour Support (PBS) for challenging behaviour is a complex intervention. Process evaluation is pivotal in fully understanding the mechanisms and contextual factors that impact on participant outcomes.

AIMS

To conduct a process evaluation of a national clinical trial investigating the impact of PBS-based staff training on the level of challenging behaviour in adults with intellectual disability.

METHOD

The Medical Research Council guidance for process evaluation of complex interventions was followed. Semi-structured interviews with 62 stakeholders from the intervention arm (service users, family and paid carers, service managers, staff who delivered the intervention and PBS trainers), quantitative data from the study database and an external evaluation of the quality of the PBS plans were used.

RESULTS

Twenty-one health staff volunteered to be trained in delivering PBS. Available log data from 17 therapists revealed that they worked with 63 participants a median of 11.50 hours (IQR 8-32). Only 33 out of 108 reports had included all elements of the intervention. Another 47 reports had some elements of the intervention. All PBS plans were rated weak, indicating insufficient quality to impact challenging behaviour. Stakeholders reported an appreciation of PBS and its potential to impact quality of care and engagement with the participant. However, they also identified important challenges including managing PBS-related caseloads, paid carer turnover and service commitment to the delivery of PBS.

CONCLUSIONS

PBS-based staff training was well received, but therapists found it difficult to undertake all the elements of the intervention in routine care. Implementing a workforce training strategy is important to better define the active components of PBS, and resource implications if the intervention is no better than usual care.

Genetic testing in children and adolescents with intellectual disability

PURPOSE OF REVIEW

Investigation for genetic causes of intellectual disability has advanced rapidly in recent years. We review the assessment of copy number variants (CNVs) and the use of next-generation sequencing based assays to identify single nucleotide variation in intellectual disability. We discuss the diagnostic yields that can be expected with the different assays. There is high co-morbidity of intellectual disability and psychiatric disorders. We review the relationship between variants which are pathogenic for intellectual disability and the risk of child and adolescent onset psychiatric disorders.

RECENT FINDINGS

The diagnostic yields from genome wide CNV analysis and whole exome sequence analysis are high - in the region of 15 and 40%, respectively - but vary according to exact referral criteria. Many variants pathogenic for intellectual disability, notably certain recurrent CNVs, have emerged as strong risk factors for other neurodevelopmental disorders such as autism spectrum disorders, attention deficit hyperactivity disorder, and schizophrenia.

SUMMARY

It is now conceivable that etiological variants could be identified in the majority of children presenting with intellectual disability using next-generation sequencing based assays. However, challenges remain in assessment of the pathogenicity of variants, reporting of incidental findings in children and determination of prognosis, particularly in relation to psychiatric disorders.

A hypomorphic inherited pathogenic variant in DDX3X causes male intellectual disability with additional neurodevelopmental and neurodegenerative features

Background

Intellectual disability (ID) is a common condition with a population prevalence frequency of 1–3% and an enrichment for males, driven in part by the contribution of mutant alleles on the X-chromosome. Among the more than 500 genes associated with ID, DDX3X represents an outlier in sex specificity. Nearly all reported pathogenic variants of DDX3X are de novo, affect mostly females, and appear to be loss of function variants, consistent with the hypothesis that haploinsufficiency at this locus on the X-chromosome is likely to be lethal in males.

Results

We evaluated two male siblings with syndromic features characterized by mild-to-moderate ID and progressive spasticity. Quad-based whole-exome sequencing revealed a maternally inherited missense variant encoding p.R79K in DDX3X in both siblings and no other apparent pathogenic variants. We assessed its possible relevance to their phenotype using an established functional assay for DDX3X activity in zebrafish embryos and found that this allele causes a partial loss of DDX3X function and thus represents a hypomorphic variant.

Conclusions

Our genetic and functional data suggest that partial loss of function of DDX3X can cause syndromic ID. The p.R79K allele affects a region of the protein outside the critical RNA helicase domain, offering a credible explanation for the observed retention of partial function, viability in hemizygous males, and lack of pathology in females. These findings expand the gender spectrum of pathology of this locus and suggest that analysis for DDX3X variants should be considered relevant for both males and females.

Electronic supplementary material

The online version of this article (10.1186/s40246-018-0141-y) contains supplementary material, which is available to authorized users.

Genetic testing in intellectual disability psychiatry: Opinions and practices of UK child and intellectual disability psychiatrists

Background

An increasing number of genetic causes of intellectual disabilities (ID) are identifiable by clinical genetic testing, offering the prospect of bespoke patient management. However, little is known about the practices of psychiatrists and their views on genetic testing.

Method

We undertook an online survey of 215 psychiatrists, who were contacted via the Royal College of Psychiatrist's Child and Adolescent and Intellectual Disability Psychiatry mailing lists.

Results

In comparison with child and adolescent psychiatrists, intellectual disability psychiatrists ordered more genetic tests, referred more patients to genetic services, and were overall more confident in the genetic testing process. Respondents tended to agree that genetic diagnoses can help patient management; however, management changes were infrequently found in clinical practice.

Conclusions

Differences are apparent in the existing views and practices of child and adolescent and intellectual disability psychiatrists. Developing training and collaboration with colleagues working in genetic services could help to reduce discrepancies and improve clinical practice.