Method, reagents and kit for diagnosis and targeted screening for

Abstract

Reliable and cost effective testing for mutations in the RB1 gene can be accomplished by (a) quantitatively amplifying exons of the sample RB1 gene using primers complementary to intron regions flanking each exon; and (b) determining the lengths and/or quantities of the amplification products for each exon and comparing that length or quantity to the length or quantity of amplification products obtained when a wild-type RB1 gene is amplified using the same primers. Differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample RB1 gene. Differences in quantity reflect the complete absence of an exon, or heterozygosity for a mutant exon. Next, the nucleic acid sequence of each exon found to contain an insertion or deletion mutation is determined, or of all exons in the event no insertion or deletion mutations are identified. Preferably, the amplification of the exons is multiplexed so that more than one exon is amplified in a single vessel using sets of primers which provide gene fragments of distinctive lengths when used to amplify a normal RB1 gene.