Acute angulation of the left renal artery imitating renal artery stenosis in a patient with neurofibromatosis type 1.

Abstract

Here, we present a 30-year-old hypertensive female Introduction patient with NF1 in whom, despite findings suggestive of RAS, obtained by non-invasive techniques, renal Neurofibromatosis type 1 (NF1, von Recklinghausen’s arteriography failed to demonstrate stenosis and the disease) is an autosomal dominant genetic disorder hypertension was therefore classified as essential and with an estimated incidence of ~1 in 4000 births [1]. easily controlled by b-blockade. Half of all cases are new mutations, of which, to date, almost 200 have been identified. The NF1 gene, which is located on the long arm of chromosome 17 in band Case q11.2, was identified and its protein product characterized in 1990 [2,3]. The gene is large and codes for a A 30-year-old woman was admitted to our hospital 2818 amino acid protein called neurofibromin, the because of recently discovered hypertension. The function of which remains unknown, although a porpatient had been well until 5 weeks earlier when her tion of the protein may be a GTPase activator involved blood pressure was measured coincidentally and was in the regulation of Ras activity, thereby controlling found to be 220/110 mmHg. There was nothing of cellural proliferation [4]. The diagnosis of NF1 is note in her past medical history; her family history based largely on clinical criteria established by the was also negative, and she was on no medication. National Institute of Health (NIH) Consensus Physical examination revealed, in addition to the arterDevelopment Conference on Neurofibromatosis in ial hypertension, many cafe-au-lait macules (5–20 mm) 1987 (Table 1) [5]. and freckling on the trunk, axillae, hands and inguinal Hypertension is frequent in NF1 and may develop region. There was one neurofibroma on the anterior at any age. In most cases, the hypertension is ‘essential’, thoracic wall and one plexiform neurofibroma on the but pheochromocytoma and renal artery stenosis back (Figure 1). Slit lamp examination of the iris (RAS) should always be considered as remediable causes in hypertensive NF1 patients [6 ].