FLNA and FG syndrome: In contrast to FLNC, FLNA is expressed in virtually every human tissue, and mutations in the FLNA gene result mainly in congenital malformations, along with cardiac phenotypes such as myxomatous mitral valve disease [48], non-syndromic mitral valve dystrophy [31], familial Ebstein’s anomaly, a rare form of congenital heart disease [51], prolapsed atrioventricular valves [52], and also in FG syndrome, a rare syndromic cause of X-linked mental retardation associated with congenital heart disease [53].