ABSTRACT
Ataxia-telangiectasia is an autosomal recessive disorder affecting 1/40000 to 1/100000 of reported populations. There is 25% possibility for having an affected child when parents are carriers for ATM gene mutation. There is no cure available for this disease and prenatal testing is strongly recommended to prevent this disease. Although preferred method is the direct mutation analysis of ATM gene, but large size of the ATM gene with 63 exons and the large number of possible mutations in patients considerably limit efficiency of mutation analysis as a choice in diagnosis. Indirect method is a better tool when parents are not carriers of founder mutation and pass different mutations to their children. Indirect molecular diagnosis using ATM related molecular markers facilitates prenatal diagnosis of AT children. In this study, four molecular markers: D11S2179, D11S1787, D11S535, D11S1343 are genotypes in 12 unrelated families [19 patients] from different regions of Iran. Those markers are amplified using extracted sequence primers from Gene Bank with their described PCR conditions. The amplified products were separated using denaturing PAGE gels, and the data were analyzed to detect their pattern of inheritance in each family. In all families, segregation of alleles were according to mandelian inheritance and affected chromosomes were distinguishable from unaffected ones. All carriers and affected patients were diagnosed accurately. Thus, this method is effectively usable in prenatal diagnosis of ataxia telangiectasia