Objective Muscle segment homeobox gene（MSX）1 has been proposed as a gene in which mutations may contribute to nonsyndromic cleft lip with or without cleft palate（NSCL/P）. To study MSX1 polymorphisms in NSCL/ P by means of polymerase chain reaction- single- strand conformation polymorphism（PCR- SSCP）, and investigate the association of MSX1 exons 1 polymorphisms with NSCL/P. Methods DNA were extracted from blood samples from NSCL/P and unrelated normal subjects. Genome DNA from peripheral leukocyte with these blood samples were extracted, which was used as template to amplify desired gene fragment of MSX1 exons 1 by means of polymerase chain reaction（PCR）. The PCR products were examined by single- strand conformation polymorphism（SSCP）. The MSX1 exons 1 polymorphisms were examined by sequencing if mutations were found. Results MSX1 genes of exon 1 mutation was not been found in the NSCL/P and unrelated normal subjects by SSCP. Conclusion No correlation between MSX1 exon 1 and NSCL/P was found. MSX1 exon 1 may not be a key gene（susceptibility gene）in NSCL/P.
