How is triple X syndrome diagnosed?

The diagnosis of triple X syndrome is made by looking at the complete set of chromosomes of the individual. This is called a karyotype. A karyotype shows the number and visual appearance of the chromosomes found in the cells of a person.

• Before birth
  The diagnosis can be made by taking a sample of amniotic fluid, or other foetal tissue, to look at the foetal karyotype.
• After birth
  The diagnosis is confirmed by taking a sample of blood or other tissue to obtain a karyotype.
  

Karyotype showing triple X syndrome