Karyotyping is also known as chromosome analysis or cytogenetic testing.

Karyotyping is a test that examines the Chromosomes under a microscope, after special preparation, in a laboratory. It is most often performed on a sample of blood, but it can also be performed on other types of samples, either before birth (from the placenta or the amniotic fluid surrounding a baby) or after birth (from muscle, skin, and other tissues). Karyotyping is most likely how your r(20) diagnosis was made.

Karyotyping looks at the number, size, and structure of your Chromosomes.

Karyotyping does not look at individual genes or the DNA code of the bases (the As, Ts, Gs, and Cs).