Christmas病(因子Ⅸ缺乏),象血友病(因子Ⅷ缺乏)一样,是X连锁隐性遗传疾病。该病占英国遗传性凝血缺陷中12％。女性中血友病罕见。作者报告1例患Christ-mas病女孩。她在该家族中为第2例女性Christmas病纯合子,她的父亲有Chris-tmas病,母亲为其父的堂妹。该病人3年前7岁时摘除扁挑腺,术后长期大量出血因而需要输血,她易有瘀伤和偶有轻度鼻衄史。其兄右膝关节受伤后反复关节血肿及外伤后长期鼻衄。凝血活酶时间延长和因子Ⅸ水平低(10％)。其父拔牙后 Christmas disease (lack of factor Ⅸ), like hemophilia (factor Ⅷ deficiency), is an X-linked recessive disease. The disease accounts for 12% of the British hereditary coagulation defects. Hemophilia is rare in women. The authors report 1 case of Christ-mas disease in girls. She is the second female Christmas homozygote in this family. Her father has Chris-tmas disease and her mother is the cousin of her father. The patient was removed at the age of 7 years 3 years ago flat apical glands, a large number of bleeding after a long period of surgery and the need for blood transfusions, she was prone to bruising and occasional history of mild epistaxis. Her brother’s right knee joint injury after repeated hematoma and traumatic long-term epistaxis. Prothrombin time and factor IX levels are low (10%). His father after tooth extraction