Down syndrome (DS) has been linked with medical conditions such as anemia and periods of breathing difficulties called apneas, according to a new mouse study published online ahead of print in Function.
Researchers exposed mice to higher levels of carbon dioxide, which usually increases breathing rate and depth. However, a mouse model of DS had a reduced response to breathing higher levels of carbon dioxide and also had lower-than-normal oxygen levels.
Blood samples revealed the DS mice had anemia, resulting in a weakened ability to carry oxygen in the body. In a large human study, the research team, from the University of Health Sciences and Pharmacy in St. Louis, also determined that anemia is more common in DS. Finally, researchers performed studies on the diaphragm, the main breathing muscle in the body. They observed the muscles functioning normally and concluded the neural, not muscular components, contribute to breathing disturbances in DS.
Researchers concluded that “Ts65Dn has an altered pattern of breathing and there is justification to continue studying mechanisms of respiratory output in DS.”
“Knowing that neural, not muscular deficits contribute to calm breathing in DS is important for potential therapies,” said Lara DeRuisseau, PhD, associate professor and lead author of the study. “Since 40–50% of people with DS have sleep apnea, the reduced response to carbon dioxide could also be important to understand why people with DS stop breathing during sleep.”
