Chromosome Analysis

Find out what chromosomes are and how they are investigated using a technique called karyotyping. This short easy-to-understand animation shows how the scientist looks at the number and structure of a person’s chromosomes to help identify disorders. This test is usually ordered when a pregnant woman’s screening test results are abnormal or when a child has certain clinical features that suggest a chromosome disorder. It can also be used when a doctor is diagnosing some types of leukaemia or lymphoma.
Chromosomes are thread-like structures within each cell nucleus and they contain the body’s genetic blueprint in the form of tightly wound and packaged DNA. Humans have 23 pairs of chromosomes. When the scientist looks at them under the microscope, they are all mixed up. So the scientist sorts them into pairs to make it easier to see any abnormalities. These include an extra complete chromosome (trisomy) a missing chromosome (such as in Turner syndrome ) or parts of chromosomes missing or duplicated.