The diagnosis of hemophilia starts with a review of the family history, particularly on the maternal side. In a patient with no family history of hemophilia diagnosis frequently occurs after common procedures in infancy and childhood, such as circumcision, heel sticks, immunizations or invasive procedures like tonsillectomy or dental extractions, depending on the hemophilia severity. The most important standardized tests of hemophilia are platelet count, prothrombin time (PT) and activated partial thromboplastin time (aPTT). These tests look at the number of platelets, the time it takes for the plasma to clot, and reflect activities of the clotting factors. Laboratory test results in newborns are different from adult results. Infants are born with low vitamin K levels and receive a dose of vitamin K shortly after birth. Vitamin K affects the clotting results and makes it difficult to interpret lab tests right after birth. The platelet count and PT will be normal for age, but the aPTT will be prolonged in hemophilia A and B. Specific factor VIII and IX assays are performed on plasma samples to measure the amount of factor VIII or IX in the patient to determine the level of deficiency and classify the hemophilia severity. The principal factor assays for factor VIII and IX are based upon the aPTT test. Genetic testing are vital to identify the mutation in people with hemophilia A or B. Genetic
The diagnosis of hemophilia starts with a review of the family history, particularly on the maternal side. In a patient with no family history of hemophilia diagnosis frequently occurs after common procedures in infancy and childhood, such as circumcision, heel sticks, immunizations or invasive procedures like tonsillectomy or dental extractions, depending on the hemophilia severity. The most important standardized tests of hemophilia are platelet count, prothrombin time (PT) and activated partial thromboplastin time (aPTT). These tests look at the number of platelets, the time it takes for the plasma to clot, and reflect activities of the clotting factors. Laboratory test results in newborns are different from adult results. Infants are born with low vitamin K levels and receive a dose of vitamin K shortly after birth. Vitamin K affects the clotting results and makes it difficult to interpret lab tests right after birth. The platelet count and PT will be normal for age, but the aPTT will be prolonged in hemophilia A and B. Specific factor VIII and IX assays are performed on plasma samples to measure the amount of factor VIII or IX in the patient to determine the level of deficiency and classify the hemophilia severity. The principal factor assays for factor VIII and IX are based upon the aPTT test. Genetic testing are vital to identify the mutation in people with hemophilia A or B. Genetic