Tetrasomy


A tetrasomy is a form of aneuploidy with the presence of four copies, instead of the normal two, of a particular chromosome.

Causes

Full

Full tetrasomy of an individual occurs due to non-disjunction when the cells are dividing to form egg and sperm cells. This can result in extra chromosomes in a sperm or egg cell. After fertilization, the resulting fetus has 48 chromosomes instead of the typical 46.

Autosomal tetrasomies