Prevention of Hemophilia: Carrier Detection and Prenatal Diagnosis

With the advent of modern technology in medical sciences, it is now possible to have a choice open to the couples planning their families. When there is a family history of hemophilia it is now possible to identify almost accurately most females who carry the hemophilia gene. Women, who know they are carriers, or might be carriers, may have options for prenatal diagnosis to obtain information on fetal status.

Who is a Carrier? is a classic example of a sex linked recessive disorder. The genes that control the production of factor VIII and factor IX are located on the X chromosome. Males have one X and one Y chromosome whereas females have two X-chromosomes and no Y. Therefore, the defect in the factor VIII or IX genes on the X chromosome causes their relative deficiency and leads to a person with hemophilia (PwH) in case of a male or carrier in case of a female.

A PWH passes his abnormal X gene to all of his daughters and his normal Y to all his sons. Therefore, all his sons are essentially normal individuals whereas all his daughters become carriers of hemophilia. Similarly, carrier females having the defective X chromosome can give birth to a carrier daughter or son with hemophilia with a 50:50 chance in each pregnancy. Hence, the carriers of hemophilia are the descendants of a hemophilic father or a carrier mother. The status of a carrier can well be identified as obligatory carrier and possible carrier by their family history or family tree.

  • Dept. Of Immunohaematology13th floor, New Building, K.E.M Hospital, Parel Mumbai 400012
  • Phone 022 2413 8518