The term “allelotype” was first used by Vogelstein and colleagues (1 ), in analogy to karyotype, to describe a newly developed molecular analysis that surveyed chromosomal loss and/or aberration in a panel of human colorectal tumors. This study was the first to comprehensively screen 39 nonacrocentric chromosomal arms in surveying restriction fragment polymorphisms (RFLPs) using variable number tandem repeats (VNTRs) as probes. Simple tandem repeats, including VNTRs and microsatellite loci consisting of 1- to 5-bp repeats, have been found to be highly polymorphic and relatively stable among the human population, which facilitates the analysis of both maternal and paternal alleles. These markers have also been useful in linkage analysis when studying hereditary human disease (2 –5 ).
