Mutation analysis of the entire replicated portion of PKD1 using genomic DNA samples

The replicated portion of PKD1, which comprises nearly 70% of the length of the gene, is predicted to harbor at least 85% of the mutations present in affected autosomal dominant polycystic kidney disease type 1 pedigrees. The relative paucity of reported mutations involving this segment is attributable to the significant technical challenges posed by the genomic structure of the gene. Previous genomic DNA-based strategies were unable to evaluate exons 1 and 22 and relied on the use of 10- to 13-kb PCR products. In this report, a set of six novel primer pair combinations, which can be used with previously reported reagents to analyze all of the exons in the replicated region (exons 1 to 34), are described. No product is greater than 5.8 kb in length, and various primer combinations can be used to reduce this length in half. Using this approach, two new pathogenic mutations, four novel disease-associated missense substitutions, and six new normal variants were identified. These new reagents should prove useful to investigators interested in performing DNA testing for this disorder.