PCR Detection of a Repeat Polymorphism within the F7 Gene

A 193 bp cDNA fragment corresponding to exon 4 of the published cDNA sequence (1) for the human NFI gene was amplified by PCR using 5'-ATAATTGTTGATGTGATTUCATTG as forward primer and 5'-AATTTTGAACCAGATGAAGAG as reverse primers. This cDNA was used as a probe for hybridization of southern blots made from human DNA samples. Polymorphism: TaqI digestion yields two bands of 7.0 kb and 6.5 kb without constant band. Frequency: Studied in a total of 40 unrelated Caucasians (20 males and 20 females) Bi 7.0 kb allele: 0.4 B2 6.5 kb allele: 0.6 Frequency of heterozygosity: 0.48. Not Polymorphic For: EcoRI, PstI, PvuII in 10 unrelated Caucasians. Chromosomal Localization: Assigned to 17q1 1 within NFl gene (1). Mendelian Inheritance: Co-dominant segregation of the TaqI RFLP was observed in two informative von Recklinghausen Neurofibromatosis (NF-1) families (10 meioses). Cosegregation with the NF-1 phenotype was observed in all these families.