Bisphosphonate therapy in an infant with generalized arterial calcification with an ABCC6 mutation

AbstractGeneralized arterial calcification of infancy (GACI) is a rare genetic disorder with high infantile mortality, described to be due toENPP1, and less commonlyABCC6 mutations. Bisphosphonate treatment has been described to improve survival in ENPP1-positive GACI patients, but few studies have described bisphosphonate treatment in ABCC6-positive patients. Without therapy, patients will die before 6  months of age. Our patient is now 3 years old, former recipient twin of twin-to-twin transfusion syndrome (TTTS). Initial fetal echocardiogram at 19 weeks showed calcifications of the ascending aorta and pulmonary artery (PA). She underwent utero laser therapy, and despite resolution of the TTTS , her follow-up scans showed progressive calcification of the aorta and PA. Postnatal echocardiogram showed calcification and supravalvar stenosis of the aorta and PA. CT on day of life 6 showed calcifications in the PAs, aortic arch, and descending aorta. Quantification of valvular calcification ca n be difficult; in our patient, increasing outflow tract gradient on echocardiogram was used to monitor disease progression. Molecular testing revealed an ABCC6 gene mutation. She was started on weekly IV pamidronate (0.1–0.3 mg/kg/week) on day 8 of life then transitioned to oral etidronate (15– 20 mg/kg/day). Given progressive supravalvar aortic and pulmonary stenosis, she underwent surgical repair with patch augmentation of the PA and ascending aorta at 4 months old. She has do...
Source: Osteoporosis International - Category: Orthopaedics Source Type: research