Methods: The study group consisted of 4 affected individual with oligodontia, and their family members, 1 affected individual with oligodontia complicated by cheilopalatognathus. The control group consisted of 1 unaffected individual. DNA was extracted from all 40 individuals' venous blood. The primer was designed within MSX1 gene. The polymerase chain reaction (PCR) for the coding region of exon1 and exon2 was carried out, and the purified PCR products was sequeced and analysed with pedigree.
Results: 3 single nucleotide polymorphisms(SNPs) in exon1 have been detected, which were obtained from 3 oligodontia patients and 1 patient with oligodontia complicated by cheilopalatognathus. Among of them, the 311th site in exon 1 changes from G to A, and corresponding codon changes from encoding glycine GGC to encoding Asp GAC that is a missense mutation. The 402th site in exon1 changes from C to A, corresponding codon changes from CCC to CCA, But it encodes proline still, which is a same-sense mutation. The 458th site in exon1 changes from C to T,corresponding codon changes from GCC encoding alanine to GTC encoding valine that is a missense mutation.
Conclusion: The 3 SNPs in MSX1 probably contribute to oligodontia in humans.