Table 1.

Currently known genes contributing to isolated and syndromic BAV

Gene	Associated Malformations/Syndromes	Phenotype	Reference(s)
NOTCH1	CHD, BAV	BAV (familial and sporadic), LVOTO	McBride et al. (2008); McKellar et al. (2007); Mohamed et al. (2006); Garg et al. (2005)
FBN1	Marfan syndrome	BAV in Marfan syndrome, possibly isolated BAV (see reference)	Pepe et al. (2014)
TGFBR2	Loeys-Dietz syndrome (type 2), familial TAAD	Hypertelorism, BAV, arterial tortuosity, bifid uvula, CTD features	* See note below
TGFB2	Loeys-Dietz syndrome (type 4)	Hypertelorism, bifid uvula, BAV, pectus, arterial tortuosity, other CTD features	Lindsay et al. (2012)
SMAD6	Aortic valve malformations	BAV, AS, HTN, CoA	Tan et al. (2012)
ACTA2	Familial TAAD	TAAD, BAV	Guo et al. (2007)
NKX2–5	BAV, CHD	BAV, ASD, AS, PFO, other CHD	Qu et al. (2014)
GATA5	AVSD, BAV		Ackerman et al. (2012); Padang et al. (2013)

Acronyms: AS = aortic stenosis; ASD = atrial septal defect; CoA = coarctation of the aorta; CHD = congenital heart defects; CTD = connective tissue disorder; HTN = hypertension; LVOTO = left ventricular outflow tract obstructions; PFO = patent foramen ovale; TAAD = thoracic aortic aneurysm/dissection;

^*TGFBR2 is associated with TAAD and Loeys-Dietz syndrome type 2, but BAV is relatively uncommon in this type (see Clinical Synopsis of OMIM entry: http://omim.org/entry/610168)