TNS1 and mitral valve prolapse: Among these, TNS1, a gene that is highly expressed in the developing heart and has a probability of being intolerant to homozygous LoF variants (pRec) of 0.9 (Fig. 1B), encodes tensin, a focal adhesion protein that interacts with actin; TNS1 had six RGs and lies near a common variant associated with mitral valve prolapse; Tns1−/−mice and zebrafish have mitral valve defects (39).