Over 900 genes have been annotated within duplicated regions of the human genome, yet their functions and potential roles in disease remain largely unknown. One major obstacle has been our inability to accurately and comprehensively assay genetic variation for these genes in a high-throughput manner. We developed a sequencing-based method for rapid and high-throughput genotyping of duplicated genes using molecular inversion probes designed to unique paralogous sequence variants. We apply this method to genotype all members of two gene families, SRGAP2 and RH, among a diversity panel of 1,056 humans. The approach can accurately distinguish copy number in paralogs having up to ∼99.6% sequence identity, identify small gene-disruptive deletions, detect single nucleotide variants, define breakpoints of unequal crossover, and discover regions of interlocus gene conversion. Our analysis of SRGAP2 suggests that nonreciprocal genetic exchange akin to interlocus gene conversion can occur over long distances (> 80 Mbp) between paralogs. The ability to rapidly and accurately genotype multiple gene families in thousands of individuals at low cost enables the development of genome-wide gene conversion maps and unlocks many duplicated genes for association with human traits.