Interestingly, quantitative expression analysis on BDMR (BrachyDactyly-Mental Retardation syndrome, OMIM #600430) patients, carrying either a deletion including HDAC4 or HDAC4 mutations, resulted in the downregulation of RAI1 transcripts [110], suggesting that HDAC4 plays a role as RAI1 transcriptional regulator. The gene discussed is HDAC4; the disease is 2q37 microdeletion syndrome.