Atypical hematologic and renal manifestations in Neurofibromatosis type I: Coincidence or pathophysiological link?

Abstract

Neurofibromatosis type 1 (NF1) is an autosomal dominant, multi-system, neurocutaneous disorder that predisposes to the development of benign and malignant tumors with a birth incidence rate of 1 in 2500-3000. 50% of cases are sporadic. The diagnosis is exclusively based on clinical assessment with clinical diagnostic criteria such as café-au-lait spots, neurofibromas, axillary or groin freckling, Lisch nodules, optic pathway glioma, bony dysplasia and first-degree relative with NF1. We report a family with NF1 in which two members presented atypical clinical features in addition to the classical diagnostic criteria. Three relatives affected by NF1, a father and two of his three sons, are described. The clinical diagnosis was originally worn in all three cases, with the association many spots café-au -lait over the entire body and some axillary freckling as well as first-degree relative. One case presented an Acute Myeloid Leukemia (AML) type 2 at 10 years of age diagnosed before the revelation of bicytopenia associated pallor and isolated asthenia. A second case presented a nephrotic syndrome at 4 years of age due to the association of hydrops with headache and asthenia. Direct sequencing of NF1 led to identify the familial mutation, a previously unreported heterozygous missense mutation c.3443C > A, p.Ala1148Glu in exon 20 which segregated with all three affected patients. The family described in this report confirms the high clinical variability of NF1, even intrafamilial,…