Interestingly, mutations occurring in the region of GATA-1-like finger of RAI1 (p.Asp1885Asn and p.Ser1808Asn), in close proximity to the corresponding region of TCF20 where p.Lys1710 lies, are also associated with SMS [38, 39, 43]. This evidence concerns the gene GATA1 and Smith-Magenis syndrome.