FLNA and Osteodysplasty, Melnick-Needles type: Otopalatodigital spectrum disorder (OPDSD) is an X-linked inherited condition caused by pathogenic variants in filamin A-encoding FLNA. The X-linked OPDSD, characterized by skeletal malformations, includes otopalatodigital syndrome type 1 (OPD1) and type 2 (OPD2), frontometaphyseal dysplasia type 1, Melnick-Needles syndrome and terminal osseous dysplasia with pigmentary skin defects.