DYRK1A and DYRK1A-related intellectual disability syndrome: On the other hand, DYRK1A haploinsufficiency caused by de novo truncation or by missense-inactivating mutations was recently seen to underlie a rare, severe disorder, the DYRK1A haploinsufficiency syndrome (also known as MRD7 or Mental Retardation, Autosomal Dominant 7: OMIM#614104 and ORPHA:464311 and 268261; [44,45] and references therein).