Amplified fragment length polymorphism analysis on D5S436 locus and its application to linkage analysis in gene diagnosis of asthma

To detect the polymorphism of D5S436 locus, and to carry out an amplified fragment length polymorphism (Amp-FLP) genotyping linkage analysis in asthma families. Allele and genotype frequencies of the high polymorphic D5S436 locus were determined in 92 unrelated Chinese individuals by using polymerase chain reaction (PCR). The amplified fragments were separated by denaturing polyacrylamide gel electrophoresis and silver staining techniques. Eight alleles and 22 genotypes were observed in this population. The heterozygosity was 78.26%. The polymorphism information content (PIC) was 0.76. Amp-FLP genotyping linkage analyses were carried out in four asthma families, demonstrating that the locus was inherited according to Mendel's law and had a clear result. The PIC of D5S436 is high in Chinese individuals, so it could be used as a genetic marker of asthma in Chinese and might be useful in the gene diagnosis of asthma.