Introduction
In 2011, mutation of the NT5E gene, that encodes cluster of
differentiation (CD) 73, was found to result in specific calcifications
in patients with aneurysmal dilatation of arteries as well as joint
calcifications. These symptoms were termed calcification of joints and
arteries (CALJA).1 Since then, only 14 patients from 7
families have been reported as having CALJA.2-5Patients with CALJA often experience ischemic symptoms in the lower
extremities secondary to severely calcified and occluded arteries. CD73
is also known to play a protective role against aortic valve
calcification by hydrolyzation of adenosine monophosphate (AMP) to
adenosine.6 Although the deletion of the CD73 gene has
been reported to cause aortic valve calcification leading to valvular
stenosis in animal models,7 there are no reports of
patients with CALJA requiring an aortic valve replacement (AVR) for
aortic stenosis (AS). We present two extremely rare cases of sisters
with identical NT5E gene mutation patterns, both of whom underwent AVR
for AS.