Is 7p14.1 an orofacial cleft risk locus? Genome-wide study of copy number variation in multiple populations provides both a replication of previous studies and an alternative explanation

The 7p14.1 association observed in our study is a replication of two prior studies in independent cohorts of European ancestry. However, this locus lies in a T-cell receptor region that is subject to somatic rearrangements that decrease in frequency with age and may affect genetic association results. Our data show age effects as well as differences between blood and saliva samples. Thus, our results can be interpreted either as supporting a previously established association with orofacial clefts, or as questioning those previous results in favor of a hypothesis about the behavior of somatic rearrangements in T-cell receptor regions.