A novel duplex SSP–PCR typing method for KIR gene profiling

Killer-cell immunoglobulin-like receptors (KIR) control the function of natural killer cells. The number and type of KIR genes are substantially variable among individuals. Sequence-specific primer-directed polymerase chain reaction (SSP-PCR) based genotyping is the most commonly used method to assess the KIR gene content. However, it requires a minimum of 16 gene-specific amplifications and often yields false-negative results. Herein, we describe the development of a simple and efficient duplex SSP-PCR assay to identify the presence and absence of 16 KIR genes. This system further distinguishes subsets of KIR2DS4 and KIR3DP1 alleles. The assay was subjected to a blind validation using a panel of 78 reference DNA standards from the UCLA KIR Exchange Program, which showed 100% specificity and accuracy. Compared with the conventional SSP typing methods, the present method is an accurate, simple, cost-effective and labor-saving KIR genotyping method for high volume testing.