Overview

What is Chromosome Analysis, Blood?

Chromosome analysis, also known as karyotyping, is done to determine the genetic cause behind the abnormalities in fetus (cognitive disabilities and retarted growth), multiple miscarriages, infertility, and cancer. Chromosomes are thread-like structures which constitute the DNA and genetic makeup of an individual. Humans have a total of 46 chromosomes present as 23 pairs. If you have an anomaly in the number, size or shape of your chromosomes, this can point to a genetic disease.

Your doctor may recommend this test if your baby has signs of a genetic disorder or if you’ve had difficulty getting pregnant or have had recurrent miscarriages. This test may also be useful if you have had been diagnosed or have symptoms of leukemia, lymphoma, or a certain type of anemia.

Why is Chromosome Analysis, Blood done?

The Chromosome Analysis, Blood test is done:

• In case the pregnancy tests are abnormal
• In case of signs of chromosome abnormality disorder
• To detect chromosomal abnormality in a person or a specific abnormality in family members
• In case a person has lymphoma or leukemia or myeloma or myelodysplasia or another cancer
• In case there is suspicion of acquired chromosome abnormality

What does Chromosome Analysis, Blood Measure?

The chromosome analysis, blood tests measure the number and structure of a person’s chromosomes which helps in detecting abnormalities. Chromosomes are thread-like structures that are present inside the nucleus of each cell. They contain the genetic blueprint of the body. Each chromosome comprises of thousands of genes in specific locations. These genes play a role in a person’s inherited physical characteristics. They have an important effect on growth, development, and function.

Humans have 23 pairs of chromosomes, which means that the total number of chromosomes present are 46. From the 23 pairs, 22 pairs are known as autosomes and are present in both males and females while one pair which is known as sex chromosome is present as either XY in males or as XX in females. Normally, all cells in the body which have a nucleus contain a complete set of the same 46 chromosomes. Exceptions are the reproductive cells that are eggs and sperm, they contain a half set of 23 chromosomes. This half set is to be passed on to a child as the genetic contribution. At the time of conception in the developing fetus, these half sets combine from each parent to form a new set of 46 chromosomes.

In case of abnormality of chromosomes, both numerical and structural changes can be seen. In numerical changes, if there are more than complete set of 46 chromosomes, it will represent a change in the amount of genetic material which can be responsible for causing health and development problems. In structural changes, the severity of the problem depends upon which chromosome is altered. Even if the same chromosome abnormality is present, the type and degree of the problem may vary from person to person.