Genetic variations of NR2A1 in Asian populations: implications in pharmacogenetics studies.

HNF4α (encoded by gene NR2A1) is a dominant transcriptional regulator of various drug disposition genes. It forms a circuitry of molecular cross-talk with other nuclear receptors such as PXR and CAR to synergistically initiate transcription. This study reports on the frequency, linkage disequilibrium pattern and tag-SNP selection of NR2A1 polymorphisms in three local Asian populations, namely Chinese, Malays and Indians (n=56 subjects each). A total of 69 polymorphisms were identified in the genomic region of NR2A1, of which thirty-three were novel polymorphisms with low allelic frequencies (<0.02). The exonic region of NR2A1 was highly conserved with only 4 novel and 1 reported SNPs identified at low allelic frequencies of less than 0.02. Based on the criteria of MAF≥0.05 and R2≥0.80, there were 19, 20 and 22 tag-SNPs selected to represent the genetic polymorphisms of NR2A1 in Chinese, Malays and Indians, respectively. In-silico predictions suggested that some of these polymorphic variants may exert functional effects through affecting the binding sites of transcription and splicing factors. Our study provides valuable information on the genetic variability of NR2A1 which would be useful for pharmacogenetics studies in the local Asian populations.