Hemophilia BM in a female

Thromb Res. 1985 Mar 1;37(5):561-6. doi: 10.1016/0049-3848(85)90088-x.


A 28 year old pregnant woman was referred for genetic counselling because of a bleeding tendency and a family history of hemophilia. The hemophilia patients had 0.02 units/ml of factor IX activity and a normal concentration of factor IX antigen. In addition they had a prolonged coagulation time with bovine thromboplastin and were therefore cases of hemophilia BM. At the age of six the patient was hospitalized because of prolonged bleeding after a tooth extraction. At the age of 20 and 24 she gave birth to healthy daughters. The first delivery was complicated by a serious bleeding seven days post partum whereas the second delivery was without complications. Factor IX activity when she was three months pregnant was 0.02-0.03 units/ml and the factor IX antigen concentration was normal. Coagulation time with bovine thromboplastin was prolonged. Delivery was again normal, and she had a daughter with carrier values of factor IX. Her mother also had carrier values whereas her father was normal. The patient's hemophilia BM was probably due to extreme Lyonization in a heterozygote.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Factor IX / analysis
  • Female
  • Hemophilia B / complications
  • Hemophilia B / genetics*
  • Heterozygote
  • Humans
  • Pedigree
  • Pregnancy
  • Pregnancy Complications, Hematologic / genetics


  • Factor IX