Archive for November 8th, 2018

From Down Syndrome World Issue 3 2018

As one of the lead authors of the Medical Care Guidelines for Adults with Down Syndrome, George T. Capone, M.D., is continuing his life’s work of improving evidence-based medical care for people with Down syndrome.

FOR THE PAST 30 YEARS, George T. Capone, M.D., has specialized in providing quality care for patients with Down syndrome, always pushing for better evidence-based treatment and interventions. As a research scientist, Director of the Kennedy Krieger Institute’s Down Syndrome Clinic and Research Center (DSCRC), and Associate Professor of Pediatrics at the Johns Hopkins University School of Medicine, he has seen more than 2,500 patients, ranging in age from infants to seniors. Dr. Capone has contributed to improved care since the 1980s, and he continues to be concerned about health care for adults with Down syndrome.

Dr. Capone’s extensive knowledge, experience, and passion to improve care are the primary reasons he was tapped to join a team of physicians and researchers updating the Medical Care Guidelines for Adults with Down Syndrome, a project funded by the Global Down Syndrome Foundation.

AN EARLY SUPPORTER OF TRANSLATIONAL RESEARCH

Dr. Capone’s career treating people with Down syndrome took root in 1988, when he began a neurobiology fellowship at Johns Hopkins University School of Medicine. At the time, researchers at Johns Hopkins, including his mentor Joseph T. Coyle, M.D., were conducting groundbreaking genetic research on the link between Down syndrome and Alzheimer’s disease. Among the many projects he saw occurring in Dr. Coyle’s lab was research that used TS16 mouse models to investigate the impact that three copies of chromosome 21 — the defining characteristic of Down syndrome — has on early-onset Alzheimer’s disease. It was some of the earliest research on the subject.

This article was published in the award-winning Down Syndrome World™ magazine. Become a member to read all the articles and get future issues delivered to your door!

The time spent in Dr. Coyle’s lab helped lay the foundation for Dr. Capone’s interest in how that research could be directly applied to the health and well-being of patients. In the early 1990s, Dr. Capone joined the Kennedy Krieger Institute. There, he recognized that the DSCRC provided ample opportunity to develop hypotheses and research questions on the neurobiological and neurobehavioral basis of cognitive impairment associated with Down syndrome. The clinic’s diverse patient population allowed for “person-centered clinical research focusing on the medical and mental health conditions we see on a daily basis.” Such research, he knew, would benefit not only people with Down syndrome but also patients with its co-occurring conditions, such as Alzheimer’s disease, sleep apnea, and heart conditions.

Under Dr. Capone’s leadership, the DSCRC has conducted studies on a range of conditions, including autism-spectrum disorders and attention-deficit/hyperactivity disorder. His research has led to the characterization of autism in children with Down syndrome, uncommon neurobehavioral and developmental profiles of children and teenagers with Down syndrome, and developmental regression in people of all ages with the condition.

He has also designed and conducted several clinical pharmacology trials for drugs intended to improve memory and cognition in both children and adults, including risperidone, guanfacine, and rivastigmine.

“The science is fascinating, and the associated medical conditions are complex and perplexing,” Dr. Capone said. “The families I work with are the best, and the children and adults I interact with always amaze me.”

FORGING NEW PATHS FOR ADULT MEDICAL CARE

Dr. Capone agrees that the increased knowledge and advocacy among parents and healthcare professionals, the establishment of specialized clinics such as the DSCRC, and advancements in medical-surgical care for children have all progressed health for people with Down syndrome. Yet, despite contributions to the field of care for people with Down syndrome, more research is necessary to improve lives.

“We need to better understand the etiology-pathogenesis and risk factors associated with certain medical conditions, as well as what treatment approaches and prevention strategies are most beneficial to our patients,” Dr. Capone explained. “We also need a more organized approach to managing data sets to improve clinical decision-making, patient and caretaker outcomes, and quality of life.”

The Medical Care Guidelines for Adults with Down Syndrome will go a long way toward improving clinical decision-making and health outcomes. The current guidelines available for adults with Down syndrome were last updated in 2001 and do not adequately reflect the more than doubling of life span for people with Down syndrome since the 1980s. As adults with Down syndrome are living longer, they require care specific to their unique aging experience and risk factors.

“Many physicians in adult medicine do not have adequate training to care for people with genetic and neurodevelopmental conditions,” Dr. Capone said. “The medical conditions experienced by adults with Down syndrome can appear overwhelming and beyond the reach of many physicians, but with sufficient resources and training, we can teach primary care and other adult healthcare providers how to provide this care with confidence.

“Coming up with medical care guidelines will expose how little we really know about ‘best practices’ when caring for aging adults with Down syndrome and chronic medical conditions,” he added. “I hope it will stimulate further interest and investigation into this often neglected aspect of clinical research.”

To learn more about the Medical Care Guidelines for Adults with Down Syndrome, please visit globaldownsyndrome.org/medical-care-guidelines.   

ADVICE FOR FAMILIES AND SELF-ADVOCATES

George T. Capone, M.D., Director of the Down Syndrome Clinic and Research Center at Kennedy Krieger Institute and Associate Professor of Pediatrics at the Johns Hopkins University School of Medicine, has some advice, learned over a 30-year career, to pass along to people with Down syndrome and their families.

Don’t get caught up in comparisons.

“If your child seems different compared to other children you know with Down syndrome, don’t despair,” Dr. Capone said. “All our children are unique, and we should rejoice in these differences.”

Exercise body and mind.

“Stay physically and mentally active once you leave high school or post-secondary school,” he said. “Find your own means of self-expression through the performing arts, fitness, hobbies, and fun social activities.”

Connect.

“Stay informed and connected to the larger Down syndrome community of families and selfadvocates,” he advised.

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From Down Syndrome World Issue 3 2018

How does an extra copy of chromosome 21 drive the developmental and clinical features of Down syndrome? This question has been the subject of many investigations since 1958, when Jérôme Lejeune reported the Presence of trisomy 21 in cells of people with Down syndrome. The answer has remained elusive.

NOW, RESEARCH FROM the Linda Crnic Institute for Down Syndrome points to dysregulation of the immune system as a mechanism by which the extra chromosome would cause this multiorgan, multi-system condition. The implications of these results are profound, because they not only provide a new conceptual framework for future research, but also illuminate avenues for the development of novel diagnostic and therapeutic opportunities to improve health outcomes in Down syndrome. Of the more than 20,000 genes encoded in the human genome, chromosome 21 carries fewer than 300, the lowest number of genes on any human chromosome. While consensus among scientists is that Down syndrome is a “polygenic condition,” a condition caused by increased activity of more than one gene, it is also agreed that not all genes on chromosome 21 would contribute equally to the condition. If one were to select a random group of 300 genes, it is recognized that only a few genes would be master regulators of cellular and organismal function. What then are the master regulator genes on chromosome 21 with the greatest impact on human biology? To address this question, scientists at the Crnic Institute employed an approach known as functional genomics, which involves measurements of the activity of thousands of genes across the entire genome, to identify the gene networks most impacted by trisomy 21.

OVERACTIVE IMMUNE SYSTEMS?

The first set of results from the analysis of cells of people with Down syndrome (Sullivan et al., 2016) revealed that trisomy 21 causes constitutive activation of the gene network known as the Interferon response, a key branch of the immune system responsible for fighting off viral infections. In cells from typical people, the Interferon response was dormant, but cells from people with Down syndrome seemed to be fighting off a viral infection that just wasn’t there. These results immediately drove attention to four genes on chromosome 21 known as the Interferon receptors, which are required for cells and tissues to respond to a viral infection and whose triplication could potentially trigger constant activation of this arm of the immune system.

The second set of results from the analysis of blood samples (Sullivan et al., 2017) revealed signs of chronic autoinflammation in people with Down syndrome. Measurements of approximately 4,000 different proteins in the blood identified about 300 that are differentially abundant between people with and without Down syndrome, with about half of those 300 proteins being involved in the immune system. Importantly, this study revealed signs of both constant activation and exhaustion of different aspects of the immune system, with obvious ties to the Interferon response. It is well established that the Interferon response enhances anti-viral defenses, but too much Interferon activity eventually weakens antibacterial defenses. Indeed, the results of the blood analysis were consistent with a type of immune dysregulation caused by lifelong hyperactivation of the Interferon response.

Noteworthy, both studies revealed, among people with Down syndrome, strong inter-individual variation in the degree of activation of the Interferon response and autoinflammation, which could potentially be linked to the obvious clinical diversity in this population.

This article was published in the award-winning Down Syndrome World™ magazine. Become a member to read all the articles and get future issues delivered to your door!

GREATER INSIGHTS AND POTENTIAL TREATMENTS

These results have triggered a flurry of activity at the Crnic Institute to answer key follow-up questions: Which of the symptoms of Down syndrome could be explained by the observed immune dysregulation? To what degree is the immune dysregulation caused by triplication of the four Interferon receptors versus other genes on chromosome 21? What would be the diagnostic value of measuring immune dysregulation to predict the risk of the same person developing certain co-occurring diseases or conditions? What would be the therapeutic value of medications that inhibit the Interferon response and accompanying inflammatory process?

Several key facts are generating much enthusiasm in the pursuit of these answers. First, it is well established that a hyperactive Interferon response has negative effects on human development, as illustrated by type I Interferonopathies, a newly recognized class of genetic conditions caused by gene mutations that lead to activation of the Interferon response and share many symptoms with Down syndrome. Second, the pharmaceutical industry has developed many medications that inhibit the Interferon response, some of which are approved for the treatment of autoinflammatory conditions, such as rheumatoid arthritis, and are currently being tested for the treatment of autoimmune conditions more prevalent in Down syndrome, such as alopecia areata and vitiligo. Third, pioneer studies in mouse models of Down syndrome completed by Lenny Maroun, Ph.D., currently at the Crnic Institute, demonstrated that reducing the Interferon response improves the development of these mice (Maroun et al., 2000).

Altogether, this body of research justifies a strong investment in the study of the immune system in Down syndrome, with the obvious potential to develop diagnostic and therapeutic strategies to improve the well-being of those living with trisomy 21.

To learn more about research at the Crnic Institute, visit globaldownsyndrome.org/our-story/linda-crnic-institute.

References:

Maroun, L.E., Heffernan, T.N., and Hallam, D.M. Partial IFN-alpha/ beta and IFN-gamma receptor knockout trisomy 16 mouse fetuses show improved growth and cultured neuron viability. Journal of Interferon & Cytokine Research: the Official Journal of the International Society for Interferon and Cytokine Research. 2000; 20, 197–203.

Sullivan, K.D., Evans, D., Pandey, A., Hraha, T.H., Smith, K.P., Markham, N., Rachubinski, A.L., Wolter-Warmerdam, K., Hickey, F., Espinosa, J.M., et al. Trisomy 21 causes changes in the circulating proteome indicative of chronic autoinflammation. Scientific Reports. 2017; 7, 14,818.

Sullivan, K.D., Lewis, H.C., Hill, A.A., Pandey, A., Jackson, L.P., Cabral, J.M., Smith, K.P., Liggett, L.A., Gomez, E.B., Galbraith, M.D., et al. Trisomy 21 consistently activates the interferon response. 2016; eLife. 5.

Like this article? Join Global Down Syndrome Foundation’s Membership program today to receive 4 issues of the quarterly award-winning publication, plus access to 4 seasonal educational Webinar Series, and eligibility to apply for Global’s Employment and Educational Grants.
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