UNLABELLED: Cleft lip with or without cleft palate and cleft palate (CL/CLP/CP) is one of the most common malformations among newborns. The estimated prevalence in Latvia is 1/700. Nonsyndromic CL/CLP/CP is a complex trait determined by multiple, interacting genetic and environmental factors. MSX1 gene is one of the most important candidate-genes, which had been analyzed in relation with nonsyndromic CL/CLP/CP. The objective of our study was to examine the etiologic role of MSX1 gene mutations in the development of nonsyndromic CL/CLP/CP in Latvian population. MATERIALS AND METHODS: DNA was extracted from venous blood of 53 patients with cleft lip with or without palate. Polymerase chain reaction (PCR) was performed of selected segments of MSX1 gene. These were sequenced and analysed by comparison with reference sequence, accession Nr. AF426432 (NCBI). RESULTS: 16 DNA sequence variations were identified in 53 patient samples; 6 of them have not been previously described. Identified sequence variations localized in coding regions do not cause amino acid substitutions, therefore they are not considered as mutations with an etiological role in CL/CLP/CP development. Baltic-Taiwan joint research project "Identification of genes involved in craniofacial morphogenesis and susceptibility to orofacial clefting in a human genome scan 2004-2006".