Chromosomal Basis of Inherited Disorders

Aneuploidy, an abnormal number of chromosomes in a cell, is caused by nondisjunction, or the failure of chromosomes to separate at meiosis.

Structural rearrangements of chromosomes include both inversions and translocations, which may have detrimental effects on an organism.

The presence of extra X chromosomes in a cell is compensated for by X-inactivation in which all but one X chromosome are silenced.