10.Immune problems
Patients with Down syndrome often have abnormalities with their white blood cells. They have a high risk of leukemia, especially during their initial 5 years of life (56 times higher than regular patients). This causes immune problems, blood clotting problems, and many other symptoms found in leukemia patients. But even if they do not develop leukemia, Down syndrome patients are more susceptible to infectious diseases (12 times more susceptible according to studies). The most common infectious disease is pneumonia.