START // Trisomy 21 // Trisomy 21 and Down Syndrome //
Trisomy 21 and Down Syndrome
Trisomy 21 and Down syndrome - what is the connection?
What have those two got to do with each other?
Almost every person has 46 chromosomes:
23 from their mother and 23 from their father
People with Down syndrome usually have 47 chromosomes.
They have the 21st chromosome three times.
Hence it is also called trisomy 21.
People with trisomy 21 have Down syndrome.
That is because they have the genetic material of the 21st chromosome three times.
In this movie you can see how a trisomy 21 develops:
