Prior studies have often found a combination of rare transmitted and de novo CNVs at ASD risk regions. In our data, we observed 8 loci at which rare transmitted CNVs, present only in probands, overlapped one of the 51 regions in probands containing at least one rare de novo CNV. Conversely, in siblings we did not observe any cases in which a rare transmitted CNV, restricted to siblings, overlapped one of the 16 regions showing de novo events. Interestingly, the 8 regions in probands showing overlapping rare de novo and rare transmitted CNVs include 5 of the 6 intervals with recurrent rare de novo variants, 1q21.1, 15q13.3, 16p13.2, 16p11.2, and 16q23.3 (Figure 4), and 3 additional genomic segments with 1 rare de novo event: 2p15, 6p11.2, and 17q12.
