Possible misdiagnosis using the Xba I polymorphism for prenatal diagnosis of haemophilia A.
A mother of two haemophilia A sons presented at 7 weeks pregnancy for a prenatal diagnosis. Southern blot analysis of haemophilia DNA at the factor VIII intron 22 Xba I restriction fragment length polymorphism (RFLP) site revealed an Xba I haplotype of A-B+C-. This haplotype has been alluded to but not reported before, and when a 1.6 kb Bst XI fragment of p482.6 is used as a probe the resulting band pattern is similar to that of females heterozygous at site A.
Van de Water
N S
NS
Department of Haematology, Auckland Hospital, New Zealand.
May
S J
SJ
Browett
P J
PJ
D004247:DNA / Q000032:analysis; D015252:Deoxyribonucleases, Type II Site-Specific; D003951:Diagnostic Errors; D005167:Factor VII; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006467:Hemophilia A / Q000175:diagnosis*; D006801:Humans; D010375:Pedigree; D012150:Polymorphism, Restriction Fragment Length; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*
D005167:Factor VII; D004247:DNA; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific