Two single base polymorphisms in introns 41 and 16 of the NF1 gene.

We have characterized two intragenic polymorphisms in the neurofibromatosis type 1 (NF1) gene by direct sequencing of PCR products. The variants for these polymorphisms were initially detected on Hydrolink gels. One of the polymorphisms involves a G to A transition in intron 41 at the 28th base upstream of exon 42 with an observed 'G'/'A' heterozygosity of 0.42. The other polymorphism is a T to C transition in intron 16 at the 16th base upstream of exon 17 with an observed 'T'/'C' heterozygosity of 0.09. In combination with other documented polymorphisms in the NF1 gene, these variants should assist in genetic analysis of NF1 families.