Hereditary carrier

Punnett square: If the other parent does not have the recessive genetic disposition, it does not appear in the phenotype of the children, but on the average 50% of them become carriers.

A hereditary carrier (genetic carrier or just carrier), is a person or other organism that has inherited a recessive allele for a genetic trait or mutation but usually does not display that trait or show symptoms of the disease. Carriers are, however, able to pass the allele onto their offspring, who may then express the genetic trait.