BMPR1B mutation causes Pierre Robin sequence

BACKGROUND: We investigated a large family with Pierre Robin sequence (PRS). AIM OF THE STUDY: This study aims to determine the genetic cause of PRS. RESULTS: The reciprocal translocation t(4;6)(q22;p21) was identified to be segregated with PRS in a three-generation family. Whole-genome sequencing and Sanger sequencing successfully detected breakpoints in the intragenic regions of BMRP1B and GRM4. We hypothesized that PRS in this family was caused by (i) haploinsufficiency for BMPR1B or (ii) a gain of function mechanism mediated by the BMPR1B-GRM4 fusion gene. In an unrelated family, we identified another BMPR1B-splicing mutation that co-segregated with PRS. CONCLUSION: We detected two BMPR1B mutations in two unrelated PRS families, suggesting that BMPR1B disruption is probably a cause of human PRS. METHODS: GTG banding, comparative genomic hybridization, whole-genome sequencing, and Sanger sequencing were performed to identify the gene causing PRS.