Renovascular disease and hypertension in children with neurofibromatosis

Abstract

Neurofibromatosis type 1 (NF1) is associated with vascular lesions, such as renal artery stenosis, and secondary hypertension. The real prevalence is largely unknown, particularly in children. We observed 27 patients with NF1, mean age 12.8 years (range 4.2-24 years), for 2-10 years to assess the association of NF1 with vascular abnormalities and secondary hypertension. Patients were studied with angiography, 24-h blood pressure monitoring, a captopril test, and Doppler ultrasonography of aorta and renal arteries. The prevalence of hypertension was 18.5%; 61.5% of patients studied with angiography had vascular lesions, half of whom were apparently normotensive. However, they had abnormal 24-h blood pressure monitoring, which was a first sign of poor blood pressure control. Those patients with severe hypertension (11.1%) were successfully treated with percutaneous transluminal angioplasty (PTA); stenosis recurred in 2 of 3 patients after a 2-year follow-up period, and was responsive to drugs. We conclude that hypertension is a frequent complication of NF1 in pediatric patients, it is usually secondary to typical vascular lesions, and requires careful follow-up. Ambulatory blood pressure monitoring (24-h) is a sensitive method for detecting initial alterations of the blood pressure pattern. PTA may be an effective treatment in this condition.

Diagnostic and medical strategy for renovascular hypertension: report from a monocentric pediatric cohort

“…We propose that tomography is performed for severe cases, which are defined by a young age, NF1 disease, multiple lesions, or mid-aortic syndrome detectable by Doppler. NF1 was considered as a severity criterion because of the importance of identifying lesions, which are often present as multiples and located at the ostia before to perform a PTA reputed to be difficult [4,10,19]. Likewise, younger ages were considered as a criterion of severity because of the difficulty in performing an accurate Doppler at this age and due to the young age of mid-aortic syndrome in our cohort.…”

Clinical and genetic aspects of neurofibromatosis 1

“…A renovascular cause is often found in children with NF1 and hypertension. 49,50 A characteristic NF1 vasculopathy can cause arterial stenosis, occlusion, aneurysm, pseudoaneurysm, rupture, or arteriovenous fistula formation. NF1 vasculopathy involving the arteries of the heart or brain or other major arteries can have serious or even fatal consequences.…”

The neurofibromin GAP-related domain rescues endothelial but not neural crest development in Nf1-/- mice

“…The effects of NF1 are seen in nearly all parts of the body, such as learning disabilities (2,3), skeletal dysplasias (4), vascular abnormalities such as moya-moya and renovascular hypertension (1,5), and cardiac abnormalities such as valvar pulmonary stenosis (1,6). However, the most prominent clinical symptoms affect tissues of neural crest origin (7), such as the peripheral nervous system and melanocytes, with clinical manifestations such as neurofibromas, axillary freckling, and café-au-lait spots.…”