Identification of single-nucleotide polymorphisms in the human LPIN1 gene

 Because mutations in the murine analog of human LPIN1 cause lipodystrophy in mice, LPIN1 is a candidate gene for human lipodystrophy syndromes. To identify possible disease mutations and/or common single-nucleotide polymorphisms (SNPs), we developed primer pairs to amplify the 21 exons of LPIN1. We used these primer pairs to sequence LPIN1 in lipodystrophy patients who had no mutations in known lipodystrophy genes, and also in normal control subjects. We found no rare LPIN1 coding sequence variants that were exclusive to patients with lipodystrophy. However, we found four silent SNPs, namely, +17C>T in exon 3, 935C>T in exon 5, and 1040G>A and 1079G>C in exon 6, and one nonsynonymous SNP, namely, 2211C>T (P616S) in exon 15. The findings suggest that LPIN1 mutations are not commonly seen in patients with lipodystrophy who had no mutations in known disease genes. However, the identification of amplification primers and SNPs provides tools to further investigate LPIN1 for association with other phenotypes.