Kidney traits on repeat—the role of MUC1 VNTR

To a non-geneticist, variable number tandem repeat (VNTR) genetic variants may be a mystery, and indeed we are only beginning to understand their role in rare and complex diseases. VNTRs are genomic sequences seven to thousands of base pairs long that are repeated in tandem from two to hundreds of times. In contrast to single nucleotide polymorphisms (SNPs), which are classical, mostly biallelic, instruments for genetic association studies, VNTRs are multiallelic, with highly polymorphic numbers of repeats for each copy of an individual’s genome and between individuals.