My Pregnancy

46 Chromosomes, 23 pairs

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. 

Autosomes

Twenty-two of these pairs, called autosomes, look the same in both males and females. 

23rd pair

The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.

Genetic disorder

Genetic disorders are caused by changes in a person’s genes or chromosomes. 

Aneuploidy

Aneuploidy is a condition in which there are missing or extra chromosomes. 

Trisomy

In a trisomy, there is an extra chromosome. In a monosomy, a chromosome is missing. 

Mutations

Inherited disorders are caused by changes in genes called mutations. 

Examples

Inherited disorders include sickle cell disease, cystic fibrosis, Tay-Sachs disease, and many others. 

In most cases, both parents must carry the same gene to have an affected child.