Family-based study shows heterogeneity of a susceptibility locus on chromosome 8q24 for nonsyndromic cleft lip and palate

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate is a common birth defect. Although a number of susceptibility loci have been reported, replication has often been lacking. This is likely due, in part, to the heterogeneity of datasets and methodologies. Two independent genome-wide association studies of individuals of largely western European extraction have identified a possible susceptibility locus on 8q24.21. METHODS: To determine the overall effect of this locus, we genotyped six of the previously associated single nucleotide polymorphisms in our Hispanic and non-Hispanic white family-based datasets and evaluated them for linkage and association. In addition, we genotyped a large African American family with nonsyndromic cleft lip with or without cleft palate that we had previously mapped to the 8q21.3-24.12 region to test for linkage. RESULTS: There was no evidence for linkage to this region in any of the three ethnic groups. Nevertheless, strong evidence for association was noted in the non-Hispanic white group, whereas none was detected in the Hispanic dataset. CONCLUSION: These results confirm the previously reported association and provide evidence suggesting that there is ethnically based heterogeneity for this locus.