[Neurofibromatosis type 1. Splicing mutation detected by MLPA and DNA sequencing in Argentina]

Neurofibromatosis type 1 (NF1) is a dominant autosomic genetic disorder, with a birth incidence of 1 in 2500-3000. Diagnosis is difficult because of the size of gene NF1 that has few hot-spots sites, the absence of a clear genotype-phenotype relation, and a heterogeneous clinical manifestation. A NF1 suspected case from Jujuy province was analyzed by multiplex ligation-dependent probe amplification (MLPA). Mestizo female teenage (Amerindian/European), with a maxilar osteoma, lumbar lordosis, cutaneous neurofibromas and café au lait spots. MLPA detected an alteration in exon 13 of the NF1 gene. By sequencing of exon 13, a missense mutation (NM_000267.3:c.1466A>G) was found which introduces an aberrant splicing site and is registered as pathogenic in the clinical variants database of NCBI. As far as we are aware, this is the first report of a NF1 mutation in mestizo population of Northwest Argentina. 1466A>G has been described before in patients of European origin, suggesting that the affected site could be a hot-spot site of the gene. For countries as Argentina, with limited availability of molecular diagnostic methods, we propose a diagnosis algorithm by starting the mutational analysis of NF1 with MLPA. This methodology is relatively simple and of low cost, avoiding to send samples abroad for genetic analyses.