Q92.5: Duplications with other complex rearrangements

Somatic cells usually hold a complete blueprint of your body. This blueprint consists of genetic information. The genetic information is encrypted in the chromosomes. In humans, somatic cells usually have 23 pairs of chromosome, so 46 chromosomes in all. The chromosomes are passed on to the child by both parents. The mother’s chromosomes are located in the egg, the father’s chromosomes in the sperm cell.

Before a pregnancy begins, the genetic information of both parents is recombined. If there are errors, this may change the chromosomes in an egg or sperm cell. At the beginning of a pregnancy, an egg and a sperm cell merge with each other. This creates a new cell. Changed chromosomes may be passed on to this new cell from the egg or sperm cell. The cells for the body of a child then emerge from the new cell.

In the child’s cells there may then be part of the genetic information present more often than usual, for example. The genetic information may also have other changes. Sections of the chromosomes may be arranged differently than normal, for example. This can have different effects. The effects depend, among other things, on which part of the genetic information is altered.