Flanking Markers fortheGeneCausing von Recklinghausen Neurofibromatosis (NFI)

Summary Thedefective gene causing von Recklinghausen neurofibromatosis (NF1), one of the most common in- herited disorders affecting the human nervous system, was recently mapped to chromosome 17. We haveused additional DNAmarkers to further narrow and bracket the NF1 defect. A multipoint linkage analysis suggests that the NF1 gene is flanked by D17Z1 on the centromeric side and by EW207 on the telomeric side of the long arm of chromosome 17. The identification of closely linked flanking markers should allow us to develop a reliable prenatal and presymptomatic diagnostic test for this serious neurological disorder and provides the basis for applying chromosome-specific cloning techniques for the isolation and character- ization of the mutant gene. ThedefectivegenecausingvonRecklinghausenneuro-fibromatosis (NF1) was recently mapped to chromo-some17bygenetic linkage to the nerve growthfactorreceptor(NGFR)onchromosome17ql2-17q22andtotwo anonymousmarkers, D17Z1 (p3-6) and D17S71(pA10-41),