Q92: Other trisomies and partial trisomies of the autosomes, not elsewhere classified

Q92.1: Whole chromosome trisomy, mosaicism (mitotic nondisjunction)

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. Apart from the male sex chromosomes, each chromosome is normally present twice per cell.

The chromosomes are passed on to the child by both parents. To this end, the chromosomes are in the mother’s egg cell and the father’s sperm cell. When the egg cell and the sperm cell merge, a new cell forms. Then, from this cell, the cells for a new body form.

A chromosome may be present in part of the body’s cells three times instead of twice. This can happen during the development in the womb. This creates a single cell with an additional chromosome. Further cells with an additional chromosome then develop from this cell. The health effects depend, among other things, on which chromosome is affected.