THE YEAR 2001 is marked by a major achievement in the draft sequence of the human genome, which was accomplished by thousands of scientists across the globe.1,2 It has been less than 50 years since the discovery of the structure of DNA.3 We are now beginning to understand ourselves on the basis of the molecular structure of the human genome. What is even more important is the ever-increasing information on polymorphisms, or variations of the human genome. The first DNA markers used for linkage study were restriction fragment length polymorphisms (RFLPs), as demonstrated by the discovery of the chromosomal localization of the gene for Huntington disease (HD).4 Although only a handful of RFLP markers were available when the locus for HD was discovered, many polymorphic markers including RFLPs and minisatellite and microsatellite markers have been developed. The latest polymorphic markers are single nucleotide polymorphisms (SNPs).
Tsuji S. Neurogenetics in the Postgenomic Era. Arch Neurol. 2001;58(11):1758-1759. doi:10.1001/archneur.58.11.1758