To evaluate the possibility that the COL8A1 and NRXN1 rearrangements detected in TS cases could represent de-novo mutations, we applied the MLPA assay to the parents of TS cases with rearrangements in these two gene regions. We considered only the patients for which DNA from both parents was available and confirmed relatedness in each trio. This included two cases with COL8A1 duplications and three cases with NRXN1 deletions (all from Antioquia). The same duplication was found in a parent in each of the two cases with COL8A1 duplications examined, indicating that this variant was inherited. This and the observation of similar boundaries for the COL8A1 duplications in the SNP-based CNV calls (Table 2) suggest that this variant is segregating in the Antioquian population. Deletion of NRXN1 5′ exons was found in the father of one of the cases with a NRXN1 deletion (GT64.1) but not in the parents of the two other cases with this deletion, indicating a de novo mutation in these two trios. The father of case GT64.1 has a diagnosis of OCD, a condition that shows significant
