Filamin A (FlnA) plays a critical role in cytoskeletal organization, cell motility and cellular signaling. FlnA utilizes different binding sites on a series of 24 immunoglobulin-like domains (Ig repeats) to interact with diverse cytosolic proteins and with cytoplasmic portions of membrane proteins. Mutations in a specific domain, Ig10 (FlnA-Ig10), are correlated with two severe forms of the otopalatodigital syndrome spectrum disorders Melnick-Needles syndrome and frontometaphyseal dysplasia. The crystal structure of FlnA-Ig10 determined at 2.44 Å resolution provides insight into the perturbations caused by these mutations.