A highly informative, multiplexed assay for the indirect detection of hemophilia A using five-linked microsatellites.
BACKGROUND
Hemophilia A is a severe bleeding disorder caused by almost 1000 different known mutations in the F8C gene. Direct mutation analysis is sometimes difficult for this disorder. When a mutation cannot be found, linkage analysis can be used for prenatal and carrier diagnosis.


OBJECTIVE
To develop a rapid and effective system for carrier detection and prenatal diagnosis of hemophilia A based on a single-multiplexed polymerase chain reaction (PCR) reaction utilizing five microsatellite markers.


METHODS
Two intronic microsatellites and three other markers flanking the factor VIII gene were ascertained, and primers were designed for multiplex PCR amplification. A kindred with Hemophilia A was tested for linkage using the panel of primers, and informativity in the general population was ascertained by testing 50 unrelated females.


RESULTS
Co-amplification of all microsatellites was optimized using DNA extracted by standard methods. Rapid detection and sizing of products were carried out using an automated DNA sequencer. The combined microsatellite panel was informative in each of the kindreds tested, and in 100% of the 50 unrelated females (95% CI 94.2-100%).


CONCLUSIONS
This method enables the indirect detection of hemophilia A for patients in whom mutations cannot be found, facilitating carrier testing and prenatal analysis. It is rapid and straightforward compared with many other published protocols, and offers a high degree of informativity.
Harraway
J R
JR
Molecular Pathology Laboratory, Canterbury Health Laboratories, Christchurch, New Zealand. jharraway@member.rcpa.edu.au
Smith
M P
MP
George
P M
PM
D001483:Base Sequence; D005169:Factor VIII / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods; D008040:Genetic Linkage; D005819:Genetic Markers; D005820:Genetic Testing / Q000379:methods*; D006467:Hemophilia A / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D015203:Reproducibility of Results
D005819:Genetic Markers; D005169:Factor VIII