Role of SOX9 in the Etiology of Pierre-Robin Syndrome

Objective(s : Cleft lip/palate are common congenital anomalies, affecting approximately 2/1000 live births. Pierre Robin Sequence is a subgroup of the cleft palate population. Chromosomal abnormalities near the SOX9 gene disrupt the regulation of this gene and prevent the SOX9 protein from properly controlling the development of facial structures, which leads to isolated PRS. The present study was conducted to identify the role of the SOX9 gene in the etiology of Pierre robin syndrome and to study the association of SOX9 and PRS in regulating morphogenesis of the face in individuals with Cleft lip/Palate using the PCR technique and GTG banding. Materials and Methods: Molecular and cytogenetic analysis was performed in 27 subjects with cleft lip/palate and 13 age matched controls. DNA was isolated and PCR was performed for the amplification of the gene of interest and the products were run on a 2% Agarose gel and the band patterns were analyzed. The chromosomal abnormalities were analyzed from the cultured lymphocytes after GTG banding. Result: Out of 27 patients screened, deletion of the SOX9 gene was observed in 1 case for exon1 and in 2 cases for exon2. The cytogenetic analysis showed no structural or numerical abnormalities and all the patients showed normal karyotype. Conclusion: The results of molecular methods showed a positive association suggesting that the SOX9 gene is of particular importance, but the cytogenetic study didn’t seem to show a stronger association suggesting that, this method would not identify disease genes acting via other mechanisms of genetic dominance and also due to the fact that Cleft lip / palate has a multifactorial inheritance.