In our Bohring-Opitz Syndrome support group on Facebook there is a child with partial deletion of ASXL1 gene. The SNP (single nucleotide polymorphism) chromosomal microarray testing has shown that the deletion on chromosome 20 is 165 kb in size and is located in 20q11.21. It contains the last 9 exons of the ASXL1 gene.
In this particular case it is uncertain if the clinical significance of a partial deletion of ASXL1 caused BOS because the child didn’t fit the main characteristics of BOS. The geneticist suggest that this case is more comparable with a (larger) microdeletion of the 20q11.21, which is described by Iourov et al. (2013). We hope that there will be more knowledge about this particular case in future.