Search PubMed⌕ Search

Biomedical subjects

C R Rizza

Publications and source records attributed to C R Rizza.

95 records · Page 6Linked to original sources
PubMedDate not supplied

Gene deletions in patients with haemophilia B and anti-factor IX antibodies.

Christmas disease, or haemophilia B, is an inherited X-linked haemorrhagic disease which at present occurs in 798 known cases in the United Kingdom, corresponding to a frequency of about 1 in 30,000 males. Patients are deficient in the intrinsic clotting factor IX and are treated by replacement of this protein prepared from pooled plasma obtained from normal individuals. Occasionally treatment is complicated by the appearance of specific anti-factor IX antibodies. It seemed to us that this might be due to the absence of 'self' factor IX causing the immune system to regard the infused normal factor IX as foreign. The absence of all or part of the factor IX gene was an obvious possible reason for this, which we have now tested using our previously isolated gene probe. We have found four patients with gross gene defects.

Autoantibodies↗
PubMedDate not supplied

Haemophilia B caused by a point mutation in a donor splice junction of the human factor IX gene.

Haemophilia B (Christmas disease) is an inherited, recessive, sex-linked, haemorrhagic condition caused by a defect in the intrinsic clotting factor IX. This disease occurs in males at a frequency of approximately 1 in 30,000. Patients differ in the severity of their clinical symptoms, and variation in the clotting activity and in the concentration of factor IX antigen in their plasma has been demonstrated. There is probably heterogeneity in the molecular defects of the factor IX gene causing the disease. Here we study a severely affected, antigen-negative patient, and show that the only significant sequence difference from the normal factor IX gene is a point mutation changing the obligatory GT to a TT within the donor splice junction of exon f. We infer that this change is the cause of the disease in this individual. In addition, we have used oligodeoxynucleotide probes specific for this mutation to demonstrate the feasibility of carrier detection and prenatal diagnosis for relatives of the patient.

Base Sequence↗