Intronic Variant of MUTYH Gene Exhibits A Strong Association with Early Onset of Breast Cancer Susceptibility in Indonesian Women Population

OBJECTIVE: Several studies have recently indicated a huge shifting pattern toward early age onset cases in breast cancer (BC) patients. However, the studies exerted relatively limited to the Caucasian population. This preliminary study is aimed to investigate the genetic risk factors for young BC patients specifically in Indonesia population. METHODS: DNA samples were extracted from 79 BC patients aged younger than 40 years old and 90 healthy samples. These DNA samples were sequenced using Illumina NextSeq 500 platform and preprocessed to extract the single-nucleotide polymorphisms (SNPs) data. Firstly, multiple univariate logistic regressions were performed to test the association between each SNP and BC incidence in young patients. Furthermore, to analyze the polygenic effects derived from multiple SNPs, we employed a multivariate logistics regression. RESULTS: There were only 15 SNPs passed our 95% call rate threshold thus subsequently were used in the association test. One of these variants, rs3219493, emerged to be significantly associated with early-onset BC (p-value = 0.025, OR = 3.750, 95% CI = 1.178-11.938). This result is consistent with the multivariate logistic regression model, where the pertinent variant was found statistically significant (p-value = 0.008, OR = 8.398, 95% CI = 1.720-40.920). This variant was identified as an intronic variant within MUTYH gene which has been reported in several published studies to exhibit an association with the incidence of breast cancer in China, Italy and Sephardi Jews population. However, there is no evident this gene impacting the risk of developing early onset of BC in Indonesia population. CONCLUSION: Despite our limitation in terms of sample size analyzed in this preliminary study, our finding on significant association of intronic MUTHY with the early onset of BC in Indonesia led to a broadened insight of population-based unique aspect to being taken into an in-depth account for and advancement of chemotherapy.