Nucleotide substitution(s) in exon 4 resulted in the amino acid substitution of cysteine for arginine at position 306 (R306C). This mutation abolishes the interaction with NCoR/SMRT components. An EGFP was fused in-frame downstream of the coding sequence in exon 4. Cre-mediated recombination removed the floxed neomycin resistance cassette inserted downstream of EGFP. The R306C mutation represents 9% of Rhett Syndrome missense mutations. (J:203745)