CARRIER DETECTION AND PRENATAL-DIAGNOSIS BY INTRON-22 INVERSION ANALYSIS OF THE FACTOR-VIII GENE

In approximately 50% of severe haemophilia A patients the mutation is present in the form of a large chromosomal disruption in the factor VI II gene; this disruption is described as an inversion. It results in t he physical breakage and separation of exons 1-22 and exons 23-26 of t he factor VIII gene. The inversion is directly accessible to genetic a nalysis via Southern blot techniques and therefore when present has di stinct advantages for use in diagnosis, when compared to the more trad itional methods of gene tracking. We report a study of a family in whi ch the analysis of the factor VIII intron 22 inversion and its use pre natal diagnosis.