[Polymorphism of DXS15, CA13, CA22 loci in Guangdong normal population]

The aim of this study was to investigate the polymorphism of microsatellite repeats DXS15, CA13, CA22 tightly linked to FVIII gene in Guangdong population and its practical value in genetic diagnosis for hemophilia A. The polymerase chain reaction (PCR) and capillary electrophoresis (CE) methods were adopted to test the variability of the 3 microsatellite repeat in Guangdong females, including 111 females, 222 X chromosomes for detecting DXS15 polymorphism; 87 females, 174X chromosomes for detecting CA13 polymorphism; 94 females, 188 X chromosomes for detecting CA22 polymorphism. The results indicated that 11 alleles corresponding to DXS15 were found at this locus with size ranging from 140 to 160 bp. The polymorphism information content (PIC) of this microsatellite repeat was 0.82, heterozygosity was 82%. Six alleles corresponding to CA13 were found, with a size from 145 to 155 bp, and PIC was 0.56, heterozygosity was 56.2%. Four alleles corresponding to CA22 were found with size ranging from 79 to 85 bp, and PIC was 0.41, heterozygosity was 50%. It is concluded that in contrast to the information about Caucasian, the polymorphism of these 3 microsatellites differs from race to race, and region to region. DXS15, CA13 and CA22 are highly polymorphic genetic markers useful for linkage analysis of haemophilia A, which may play a vital role in detection and prenatal diagnosis for hemophilia A.