Carrier detection in hemophilia A: ABO blood group, multiple measurements, and application of logistic discrimination

✍ Scribed by Percy, M. E. ;Rusk, A. C. M. ;Garvey, M. B. ;Freedman, J. J. ;Teitel, J. M. ;Blake, P. ;Carter, C. ;Andrew, M. ;Johnson, M. ;Inwood, M. ;Andrews, D. F. ;Brasher, P. M. A. ;Opitz, John M. ;Reynolds, James F.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 536 KB
• Volume: 31
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320310421

✦ Synopsis

In healthy 20- to 50-year-old women, the ABO blood group has a significant effect on levels of von Willebrand factor (VWF:Ag, formerly VIIIR:Ag) and on factor VIII activity (F.VIII:C). However, there is no significant effect of ABO group or subject age on the ratio log e(F.VIII:C/VWF:Ag). Multiple measurements of the "ratio" on possible carriers of hemophilia A may be combined with pedigree information using logistic discrimination to yield final risk assessment. To reduce misclassification of carriers as normal women, a lower limit, specified by the logistic model, is set on the logistic carrier probabilities. In this study, the proportion of blood group A for a population of obligate carriers was significantly higher than that expected for the general population (60% vs. 42%); for a population of control women it was lower than expected (22.5 vs. 42%). The effect for the carriers came primarily from daughters of affected fathers, as 81.3% were of blood group A. These observations indicate that a "universal" discriminant should be applied with caution.