There are not a lot of people in the world who have never heard of Down syndrome and do not know what it is. The characteristics of the syndrome were first described in 1866 by Down and the syndrome bears his name nowadays. The cause of the syndrome was discovered by Lejeune and Jacobs in 1959. Trisomy 21 is the actual cause of Down syndrome. Out of all the causes of intellectual disabilities, Down syndrome is probably the most common. All the people who suffer from this syndrome have the same characteristics like mental retardation and dysmorphic facial features. Pathophysiology
The cause of the syndrome is the extra chromosome 21 and that chromosome affects almost every organ system. When that happens, a broad spectrum of phenotypic consequences occurs. Some of the most common consequences are mental retardation, life-threatening complications and dysmorphic physical features. Apart from these health problems, a child who suffers from Down syndrome will also face certain health problems like delays in physical growth, maturation, bone development and dental eruption. Not a lot of people know that abnormal physiologic functioning affects thyroid metabolism and intestinal malabsorption. This is the main reason why children with Down syndrome are more prone to frequent infections. Impaired immune responses and the incidence of autoimmunity also contribute to that. Decreased Buffering of physiologic reactions is another problem that children with Down syndrome suffer from. Due to that fact, children with the syndrome are more likely to end up suffering from diabetes. Cataracts and Alzheimer’s disease are also a probable health problem for people suffering from Down syndrome. Leukemia is another very probable problem of people with Down syndrome.
Frequency in the United States
According to certain data, one child out of every 800 is born with Down syndrome. The same data claims that every year there are 6000 children born with the syndrome in the United States alone.
Mortality and morbidity
Studies claim that some 75% of all children that are born with trisomy 21 die in embryonic or fetal life. 85% of infants do not live longer than one year. Only 50% of all infants live longer than 50 years of age. The most important factor that determines whether the infant will survive for so long is congenital heart disease. People need to know that no race is more prone to developing Down syndrome. However, males are slightly more likely to end up with the syndrome than women. Down syndrome is diagnosed shortly after birth.