R299S, which is associated with the most severe phenotype, congenital cataract, and microcornea syndrome, was associated with the most severe overall effect on the transactivation of the four crystallin expression constructs.
The MAF mutation p.Arg299Ser is the third mutation identified in association with the CCMC phenotype, and all three mutations are located in the basic region of the DNA binding domain in the MAF protein (OMIM 177075).