DETAIL MAP OF NF1 GENE 
AAGTTCGTACCGAGTAATCCGAGAC 
3' OMGP 5' EVI2B EVI2A 
i^ ^ i IT t "ifi h 
EcoRI EcoRI EcoRI EcoRI EcoRI EcoRI EcoRI 
t(1;17) t(17;22) 
Structure of part of the NFl gene (above ), in relation to a genomic map of the region ( below ). The 
map is oriented with the centromere of chromosome 17 to the left. Sequenced exons, or coding 
regions, are shown in orange, and the direction of transcription is indicated by the large orange 
arrow. The points where the translocation occurs in each of two NFl patients, t(l;17) and 
t(17;22) (jagged lines), are 50-60 kilobases apart. These points provided major clues to the 
whereabouts of the NFl gene. 
The three genes known to lie within NFl, and their orientation on the chromosome, are shown 
in pink. Sites indicated by vertical black arrows mark where the enzyme EcoRI cleaved the geno- 
mic DNA into fragments to form the restriction map. 
Only nine exons of NFl are shown here. Others exist in either direction (indicated by large 
arrows), but within this region the sequence of individual DNA base units (represented by a 
sequence of letters A, C, T, and G ) translates into a peptide capable of controlling growth signals 
within a cell. 
Adapted from White, R.L. 1991. Identification of the neurofibromatosis gene. In Origins of 
Human Cancer: A Comprehensive Review. Cold Spring Harbor, NY: Cold Spring Harbor. 
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