Supplementary Figure 1: Structural rearrangements of regions immediately upstream or downstream of the GRM1 gene.

In case 1, six mate pairs were identified with one partner located 3′ (downstream) of the GRM1 gene and the other partner situated in the 5′ part of COL12A1. A possible explanation for this distribution of mate pairs could be an insertion of GRM1 into the 5′ part of COL12A1. This would place the expression of GRM1 under the control of the COL12A1 promoter. In line with these findings, COL12A1 and GRM1 were also rearranged in case 2. However, in this case, eight mate pairs were located 3′ of COL12A1 and 5′ of GRM1. In addition, seven mate pairs were situated in the 3′ part of COL12A1 in combination with more proximal mates 5′ of GRM1. This combination of mate pairs suggests an inversion involving parts of chromosome arm 6q, which results in altered GRM1 expression under the influence of the COL12A1 promoter. In case 4, six mate pairs were identified with one partner 5′ of GRM1 and the other mate located in the 5′ part of the TBL1XR1 gene at 3q26. The orientation of the genes precludes any functional outcome of a simple translocation between 6q24 and 3q26. However, the orientation of the sequence reads demonstrated that there was an inversion associated with the rearrangement, and SNP array data in this case showed a deletion immediately upstream of GRM1. The 5′ part of TBL1XR1 could thus have been inserted 5′ of GRM1, which would place the expression of GRM1 under the control of the TBL1XR1 promoter. In case 5, 12 mate pairs were detected with 1 mate situated in the 5′ part of BCLAF1 at 6q23 and the other mate 5′ of GRM1. This suggests that there is an inversion resulting in altered GRM1 expression under the influence of the BCLAF1 promoter.