The X-Linked Carrier test is a test specifically designed for women who want a pregnancy. The test is used to investigate genetic mutations passed from a mother to her children where they cause disease.

The genetic mutations studied are linked to the X chromosome and cause X-linked recessive hereditary diseases. X-linked recessive hereditary disease has a mutation in a gene on the X chromosome and mainly affects boys. Men have one X and one Y chromosome, (XY); therefore, if the X chromosome is inherited with a mutation in a gene, men don’t have another X chromosome to compensate for the mutation, and they may be affected by a disease.

On the other hand, women have two X chromosomes (XX); therefore, if one of the X chromosomes is inherited with a mutation in a gene, women can compensate for the mutation with the other X chromosome and be healthy carriers. Since it is unlikely that women have two mutated copies of the gene which causes the disease, men are more affected by X-linked recessive inherited illness than women.

X-linked recessive Hereditary Diseases

In boys: one copy of the mutated gene is sufficient to cause the disease.

In girls: two copies of the mutated gene are needed to cause the disease; it is more likely that the woman inherits only one copy of the mutated gene and becomes a healthy carrier.