Closing gaps in care and knowledge for adults with complex genetic conditions

KEY POINTS

• Solutions are needed in Canada to meet the health care needs of the growing number of adults with complex genetic neurodevelopmental conditions who have aged out of pediatric systems into adult systems where supports are lacking.

• Adapting existing interprofessional pediatric care models into adult care would support those with the highest needs, reducing the burden on family and caregivers and on primary care.

• Supporting physicians to conduct and seek genetic testing for eligible adults would increase etiologic diagnoses for adults with complex genetic conditions.

• Improved, inclusive, population-level data can enable studies about longitudinal outcomes of genetic diseases and their impact on health care systems and could lead to better anticipatory care and interventions throughout a patient’s lifespan.

Advances in pediatric care have led to improved survival and the emergence of models of care for children with complex chronic conditions,¹ including those associated with neurodevelopmental conditions. Data suggest that these patients comprise less than 1% of children but account for about 33% of pediatric health care costs in Canada.² Advances in genomics mean that an increasing number of such children receive genetic diagnoses.³ Nearly 3000 of these children per year,⁴ and unknown numbers of others not formally identified, turn 18 and age into health care systems in Canada, where resources and prognostic data are inadequate to provide high-quality care. As people age, additional challenges accrue. To address the gaps in care and knowledge for this emerging group of adults, health systems for adults should adapt existing integrative models of care, practitioners should ensure that adult patients receive genetic testing when indicated, and the collection of population-level data for adults with genetic diseases must improve in Canada.

Complex genetic diseases associated with neurodevelopmental conditions (e.g., intellectual disability) involve lifelong medical and neuropsychiatric complexity. Few currently have genetic-specific treatments. Pediatricians are often involved in the care of children with these conditions, and multidisciplinary complex care teams have emerged in many parts of Canada in response to the need for pediatric care coordination,¹ but there is no comparable model for these same individuals upon reaching adulthood. We propose an etiologically informed approach.^3,5

A major challenge at transition to and throughout adult care for this vulnerable group is the need for patients and their caregivers to navigate adult health care systems. To reduce burden on patients and their family members or caregivers, and on the individual practitioner striving to care for adults with multisystem complexity, an obvious starting point is to adapt integrative models of pediatric care to adult medicine. An adult complex care program would require a skilled interprofessional team, along the lines of an internal medicine outpatient clinic for adults with complex rare genetic syndromes that was recently established in The Netherlands,⁶ and using elements from world-leading, Canadian, disease-specific programs for multisystem and complex genetic conditions (e.g., the Toronto Adult Cystic Fibrosis Centre [https://torontoadultcf.com/your-centre/your-team/], and the Dalglish Family 22q Clinic for adults with 22q11.2 deletion syndrome [https://www.22q.ca/]).⁵

Implementation of dedicated interprofessional teams would integrate adult-focused care with expertise and knowledge about disease natural history and optimal management, genetic testing and counselling, supported and shared decision-making, and available supports. Given the breadth of health issues involved, physician services may be best provided by a generalist with ready access to subspecialists, including geneticists and psychiatrists, and allied health professionals, such as social workers, physiotherapists, and dieticians. Others — e.g., pharmacists — may be needed as disease-specific treatments come on board. Patients graduating from pediatric centres with multiple specialists and ongoing care coordination needs, but with no primary care practitioner or access to a disease-specific adult program, could be prioritized. Expansion and sustainability could involve integration with family health teams and shared care with primary care practitioners. Improved funding models that include compensation commensurate with the time and skills necessary to manage evolving complexity would be important enablers of this model of care.

Many adults with genetic diseases did not receive a molecular or etiologic diagnosis in childhood owing to the relative recency of advances in genetic testing capabilities. Clinical genetic testing should be provided to adults with a history of neurodevelopmental or learning disorder of unknown etiology.⁷ Some clinicians may question the value of genetic testing, particularly if disease-specific therapies are not available. However, receiving an etiologic diagnosis ends the often distressing and prolonged diagnostic odyssey, and provides the circle of care with the possibility of anticipatory guidance and other supports.^7,8 As more people receive genetic diagnoses, data on natural history for shared molecular diagnoses can provide information to families about what to expect over a person’s lifespan. Practitioners can better understand how diagnosis can change management and, importantly, new treatment strategies may be developed. Notably, insurance and employment protections respecting genetic testing are now afforded by the Genetic Non-discrimination Act (2017).

Calls are increasing for medical education to build capacity in genetics at all levels and across specialties.⁸ When genetic testing is indicated, nongeneticist clinicians can often order the standard first-line test — i.e., genome-wide microarray for people with neurodevelopmental disorders. Referral to genetics can be considered; for example, to determine need for further testing. Standard scripts for pretest counselling, and modified requisition forms and test reports to increase clarity, would reduce barriers for busy clinicians. Electronic medical record alerts flagging patients for whom genetic testing is indicated could also assist with implementation.

The population prevalence and natural history of many genetic conditions are unknown. Information on outcomes has not kept pace with that of advances in genetic diagnostics that are predominantly applied in pediatrics.⁹ Canadian health administrative data (e.g., Canadian Institute for Health Information, or linkable provincial and territorial data) represent an opportunity to study the natural history of genetic diseases on a population level, and complement and broaden data obtained from clinic-based populations, including disease registries. Population-level information is crucial for estimating incidence and prevalence, tracking outcomes, and planning and assessing health services (e.g., interventions such as complex care programs). One example — examining outcomes for a model complex genetic condition — shows accrual of common late-onset conditions in young adulthood and far higher health care costs than population norms, indicating public health implications.⁵

Implementing such knowledge gains from administrative data requires International Classification of Diseases (ICD) codes, but few exist for rare genetic disease diagnoses.^5,10 Given the long timelines involved in creating new ICD codes,¹⁰ other options are required. Linking clinical genetic test results to health administrative data is a feasible possibility. Another could be linkage to genetic data from biobanks that are representative of the population, and inclusive of people with genetic diseases, facilitated by patient–family partnerships. These measures will facilitate impact and longitudinal outcome research.

Policies that enable adult complex care teams, genetic testing in adults, and population-based data collection and linkage can assist in improving care and knowledge for adults with complex genetic diseases in Canada. Studying adults with shared genetic changes could also yield insights for the common chronic diseases that affect Canada’s aging population.⁵