Concept 34: What is difference between Down Syndrome and Trisomy?

Ans:

Down syndrome and Trisomy are both genetic disorders caused by an abnormal number of chromosomes. However, they are distinct conditions with different characteristics and outcomes.

Down syndrome, also known as Trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21. This extra genetic material affects physical and cognitive development, leading to intellectual disability, characteristic facial features, and a higher risk of certain health problems such as heart defects, hearing loss, and vision problems. Down syndrome occurs in about 1 in every 700 births.

Trisomy, also known as Edwards syndrome, is a genetic disorder caused by the presence of an extra copy of chromosome 18. This extra genetic material affects development in a more severe way than Down syndrome, leading to multiple birth defects and a high rate of infant mortality. Babies with Trisomy have a small head and jaw, clenched fists with overlapping fingers, and often have heart, kidney, and gastrointestinal problems. Trisomy occurs in about 1 in every 5,000 births.

In summary, both Down syndrome and Trisomy are genetic disorders caused by an abnormal number of chromosomes, but they have different characteristics and outcomes. Down syndrome is less severe and has a higher survival rate than Trisomy 18.