Nephrol Dial Transplant (1999) 14: 1767–1770 Nephrology Dialysis Transplantation Case Report Acute angulation of the left renal artery imitating renal artery stenosis in a patient with neurofibromatosis type 1 George Vrentzos1, Emmanouil Ganotakis1, Kostas Stylianou1, Panagiotis Prassopoulos2, Dimitrios Tsetis2, Sofia Koukouraki3, Nikos Karkavitsas3 and Dimitrios Emmanouel1 Departments of 1Internal Medicine, 2Radiology and 3Nuclear Medicine, University Hospital of Heraklion, Crete, Greece 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 character- ized 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 por- patient 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 arter- Development 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 ]. Table 1. Diagnostic criteria for neurofibromatosis 1 (NF1) The patient should have two or more of the following: 1. Six or more cafe ´-au-lait spots 1.5 cm or larger in post-pubertal individuals 0.5 cm or larger in pre-pubertal individuals 2. Two or more neurofibromas of any type or one or more plexiform neurofibroma 3. Freckling in the axilla or groin 4. Optic glioma (tumour of the optic pathway) 5. Two or more Lish nodules (benign iris hamartomas) 6. A distinctive bony lesion Dysplasia of the sphenoid bone Dysplasia or thinning of long bone cortex 7. A first degree relative with NF1. Correspondence and offprint requests to: E. S. Ganotakis, University of Crete, School of Medicine, University General Hospital, Fig. 1. Many cafe ´-au-lait macules and one plexiform neurofibroma Department of Internal Medicine, PO Box 1352, Heraklion 71110, Crete, Greece. on the back in the 30-years-old female patient. © 1999 European Renal Association–European Dialysis and Transplant Association