Karyotype Analysis: Understanding Genetic Diseases

Simply put, a karyotype is a picture of a person's chromosomes. This picture can help researchers and health care professionals determine if a person has or will develop a genetic disease. The information about genetic diseases is stored in our chromosomes. A karyotype with no indication of genetic diseases will have 46 chromosomes, including 22 pairs of autosomes and two sex chromosomes, which determine a person's gender. Any abnormalities in the chromosomes may be an indication of a genetic disease.

Instructions

• 1

  Researchers start the karyotype by first isolating and staining chromosomes and then placing them under a microscope.

• 2

  Through the microscope, a picture is taken. The picture must be cut up, separating the individual chromosomes.

• 3

  The chromosomes are then rearranged according to size from largest to smallest.

• 4

  A medical professional known as a cytogeneticist then examines the rearranged chromosomes and looks for abnormalities, such as too many, too few, missing pieces, or mixed up pieces. For example, a karyotype that has three copies of chromosome 21 has one too many. That person would have the genetic disease known as Down syndrome, or trisomy 21.