Purpose: BAT-26 is one of the representative markers for microsatellite instability evaluation and presents different polymorphisms in different ethnic populations. The current knowledge of its comparative polymorphism between healthy individuals and cancer patients in the Chinese population is insufficient. This study aims to analyze germline polymorphic variations of BAT-26 between healthy individuals and cancer patients in Chinese from Jiangsu province and the associated cancer risk implications.
Methods: The various BAT-26 alleles and their percentages in cervical cells from 500 healthy women were assessed by direct sequencing. Twenty of these samples were also analyzed by fragment analysis. BAT-26 of blood DNA from 24 healthy individuals and 247 cancer patients was analyzed by fragment analysis.
Results: Compared with the sequencing results, 122.6-122.9 bp, 123.4-123.8 bp and 124.1-124.8 bp corresponded to the A25, A26 and A27 alleles, respectively. The 524 healthy individuals showed 4.58%, 92.18% and 3.24% of A25, A26 and A27, respectively. The variant alleles A18, A24, A28, A29 and A32 were only found in cancer patients, accounting for 0.81%, 0.40%, 0.40%, 0.40% and 0.40%, respectively; the A25, A26 and A27 alleles in cancer patients accounted for 6.48%, 77.33% and 13.77%.
Conclusions: Healthy individuals had a stable BAT-26 profile within the quasimonomorphic variation range (QMVR), but cancer patients harbored variant alleles outside QMVR and showed a trend from quasimonomorph to polymonomorph, suggesting that variant alleles of BAT-26 in germline cells may be regarded as a potential marker of higher cancer risk in the Chinese population from Jiangsu province.