A New de novo Mutation Associated with Neurofibromatosis (NF-1)

Abstract

Neurofibromatrosis type 1 (NF-1) in the most common neurocutaneous disease with a autosomal dominant inheritance pattern and a frequency of 1:3.500 lives births in the general population, regardless of race and sex. NF-1 is a progressive disorder characterized by multiples cafe-au-lait macules, neurofibromas, Lish nodules and others manifestations such as bone abnormalities, short stature, epilepsy, learning disabilities, hyperactivity, with a highly variable and unpredictable expression. Half of its cause comes from different mutations in a gene on chromosome 17, resulting in less or performance neurofibromin having the regulatory domain of tumor activity. The other 50% of the case are caused by de novo mutation. It is an infant 13 months old, no family history of neurofibromatosis, which features six cafe-au lait spots 1 cm of diameter in the legs, chest, auxiliary region a and short stature. The clinical diagnostic criteria of NF-1 were established by The National Institutes Heath Consensus Development Conference in 1987. It has been suggested that pathogenic mutation in the NF-1 gene be added to the list of diagnostic criteria, but not yet accepted. A molecular genetics study showed an alteration in exon 16 c.2540T>G (p.Leu847 Arg). No genetic alterations found in phenotypic parents. After six year of follow-up she was not observed clinical or radiographic abnormalities. The genetic study is mandatory for confirmation of the suspected diagnosis and to monitor de novo mutations that knowledge and phenotypic expression thereof.