A Novel Locus For Parietal Foramina Maps To Chromosome 4q21-23

Parietal foramina [PFM] inherited usually as autosomal dominant model is an extremely rare developmental defect characterized by a symmetrical, oval hole in the parietal bone. It can be present as either an isolated feature or as one of the signs of a different syndrome. PFM1 and PFM2 have been found to be caused by mutation in the MSX2 and ALX4 genes respectively, the former being located on chromosome 5 and the latter on chromosome 11. After the exclusion of linkage at both the above loci in a large Chinese pedigree with autosomal dominant PFM, we found linkage between PFM and markers on the chromosome 4q21-23 region after a genome wide search. The maximum LOD score from two point linkage analysis is 3.87 for marker D4S2961. The analysis of co-segregated haplotype localized the region to a 20-cM interval flanked by marker D4S392 and D4S2945, and therefore we mapped a new locus for PFM.