MSX1 and cleft palate: A key susceptibility locus for nonsyndromic cleft lip with or without cleft palate on chromosome 8q24 was identified in a genome wide association study.[57] Case-control association studies have provided evidence that variants in the genes MTHFR, ARNT, TGFA, GAD1, MSX1, RARA, TGFB3 are associated with the CL/P phenotype.