Short answer: Yes.
Fused leaflets?
The condition you’re referring to is known as Congenital bicuspid aortic valve (BAV). It is the most common congenital heart valve abnormality, present in 1-2% of live births. Normally there are three leaflets (a.k.a. cusps) comprising the aortic valve. BAV refers to the situation when there are only two cusps, a hemodynamically less favorable scenario.
Although generally benign in itself, BAV has been associated with an increased risk of several serious complications. In particular, aortic stenosis, a condition in which the blood flow exiting the heart is limited by a narrowed valve, is more common in individuals with BAV and often occurs at a younger age. Aortic stenosis in BAV patients is also frequently accompanied by aortic insufficiency, back flow through the valve. Both properties reflect the anatomic descriptor you give: ugly.
Is BAV hereditary?
Yes. This can be demonstrated by looking at familial clustering of the condition. In one study, the researchers started with thirty patients diagnosed by echocardiography with congenital BAV.* All first-degree relatives were contacted, and 90% of them agreed to undergo echocardiography. Of those, 9% were found to have BAV. This is significantly higher than the baseline population risk (~1%). The distribution was compatible with an autosomal dominant inheritance pattern with incomplete penetrance.
A more recent study used fancy math to determine the heritability of BAV.** They found that 89% of the risk for BAV is due to heritable factors.
*This paper is available in full for free and provides a nice review of the background (summarized here) as well as the findings I presented:
Huntington K, Hunter AG, Chan KL. A prospective study to assess the frequency of familial clustering of congenital bicuspid aortic valve. J Am Coll Cardiol. 1997 Dec;30(7):1809-12.
**Cripe L, Andelfinger G, Martin LJ, Shooner K, Benson DW. Bicuspid aortic valve is heritable. J Am Coll Cardiol. 2004 Jul 7;44(1):138-43.