Although scientists have long known that Down syndrome is caused by the presence of an extra copy of chromosome 21, symptoms can manifest in different ways in individuals with Down syndrome. Some people with Down syndrome are at reduced risk of some disorders such as hypertension and some cancers, but their risk of other conditions like autoimmune disease and Alzheimer's may be increased. These risk factors are one aspect of the mystery of variability in Down syndrome, and researchers have not known what causes that variability in how the many ways this condition can present. A new study has provided some novel insights, however.
Scientists have now identified distinct molecular subtypes of Down syndrome that could explain the variability among those with the condition, and may lead to new ways to manage it that are more personalized. The findings have been reported in Nature Communications.
In this study, researchers analyzed the activity of genes that are found on chromosome 21 in Down syndrome patients. Data from hundreds of volunteers was included as part of the Crnic Institute Human Trisome Project. This effort revealed various gene overexpression patterns in these individuals. By applying computational tools to this data, the investigators revealed three molecular subtypes of Down syndrome.
"There is remarkable variety in terms of developmental and clinical features in people with Down syndrome, and we strongly believe that this diversity is the key to making discoveries that will improve health outcomes and increase life expectancy in this deserving population," said co-corresponding study author Dr. Joaquin Espinosa, the executive director of the Linda Crnic Institute for Down Syndrome (Crnic Institute) at the University of Colorado Anschutz Medical Campus and director of the Human Trisome Project.
"These discoveries mark a transformative step toward developing better medical care for individuals with Down syndrome," noted first study author and Crnic Institute Research Associate Micah Donovan, PhD.
Researchers will also be able to use this data to develop more tailored treatments that address the unique features of each subtype.