Analysis of the two microsatellite repeat polymorphisms of the factor VIII gene in the Turkish population.

DNA-based diagnosis of haemophilia A has previously been carried out by linkage analysis using two highly informative markers, Hind III RFLP and St14 VNTR, for affected Turkish families. In the present study the number and frequency of the microsatellite alleles at introns 13 and 22 in the factor VIII (FVIII) gene were analysed in order to increase the rate of informative females and accuracy of linkage analysis. Six alleles were observed at both loci. The two most frequent alleles of each locus were the same as the two common alleles found in Anglo-Americans. The comparison of heterozygosity of both microsatellite loci showed that the Turkish population is slightly less polymorphic than Anglo-Americans but more polymorphic than Chinese, Slavs and Uzbekians. The additional use of the two microsatellite repeat polymorphisms with the previously established informative markers has been accepted as the most effective strategy in DNA diagnosis by linkage analysis for the assessment of haemophilia A carriers and affected fetuses in the Turkish population. The modifications adopted in this study for the multiplex PCR analysis of the microsatellite repeat polymorphism eliminated the use of radioactivity and sequencing gels, reducing cost and labour.