Allelic variation of BAT-26 and BAT-40 poly-adenine repeat loci in North Indians.

Analysis of mononucleotide repeats BAT-26 and BAT-40 in North Indians revealed that there were germline polymorphisms at both the loci. We evaluated BAT-26 and BAT-40 in 100 normal healthy individuals from North India. The DNA from normal blood was PCR amplified using primers flanking the BAT-26 and BAT-40 loci. The allelic variation of BAT-26 and BAT-40 ranged between 117-130 and 94-112 bp respectively. The most frequent BAT-26 allele was 122 bp, which corresponded to 26 repeats and had a frequency of 32% while that of BAT-40 was 109 bp corresponding to 39 repeats with a frequency of 26%. These results suggest that polymorphisms in these poly-adenine repeat loci limit their applicability in studying the microsatellite instability in cancers.