did not detect further rearrangements in these individuals. Aggregating the results of the SNP-based CNV calls and MLPA (Table 4), in a total of 232 cases examined we found 7 with rearrangements in COL8A1 (all from Antioquia) and 4 in NRXN1 (3 from Antioquia and 1 from the CVCR). None of the 234 Antioquian controls showed rearrangements in these two gene regions in the SNP-based calls or MLPA. To further support the notion that the CNVs observed here are not simply population polymorphisms, we checked the Database of Genomic Variants (DGV; http://dgvbeta.tcag.ca/dgv/app/home), a curated catalogue of human structural variation, for CNVs in the NRXN1 and COL8A1 gene regions. While there is a considerable number of CNVs in both regions, all of the CNVs that lie within the respective gene itself are between a few hundred bp and ∼100 kb long, and therefore significantly shorter than the variants described here. More importantly, the majority of these variants do not affect any of the exons of the respective genes, the only exception being a 100 kb deletion affecting NRXN1 exons 7-9 (DGV Variation_2383). This variant affects a different region from the variants observed here; in addition, it was found only in one
