Summary
The characterization of inherited diseases of platelets has provided valuable information
about platelet physiology and platelet protein function. Genetic studies on patients
with Glanzmann thrombasthenia, the Bemard-Soulier syndrome, and platelet-type von
Willebrand disease have been confined to abnormalities of the GPIIb-IIIa and GPIb-IX
receptor complexes. The primary molecular technique used in these analyses has been
the polymerase chain reaction (PCR). The amplified PCR products are either directly
sequenced, or used to screen for abnormal regions of the genes which are then sequenced.
This review examines the known mutations in GPIIb-IIIa and GPIb-IX, focusing on those
genetic issues which should dictate decisions regarding the approach to identifying
molecular defects. The techniques for characterizing mutant alleles in Glanzmann thrombasthenia
and Bernard-Soulier syndrome are described and a general strategy is offered. Because
mutations resulting in reduced levels of transcripts can be missed when screening
RNA, an argument is made for using genomic DNA as the primary material for mutation
detection.