what is monosomy

Monosomy is a genetic condition in which only one chromosome from a pair is present in cells instead of the two copies usually found in diploid cells. Partial monosomy occurs when a portion of one chromosome in a pair is missing. Monosomy can cause certain human diseases such as Turner syndrome and Cri du chat syndrome. Turner syndrome is the only full monosomy that is seen in humans, and all other cases of full monosomy are lethal and the individual will not survive development. Some examples of partial monosomy include 1p36 deletion syndrome and 17q12 microdeletion syndrome. A monosomy occurs when a person has too few chromosomes, and the name refers to the fact that there is one unpaired chromosome or partial chromosome.