NS22: A highly polymorphic complex microsatellite marker within the ATM gene

We have found a complex repeat sequence (NS22) that is highly polymorphic a nd located within intron 45 of the ataxia-telangiectasia gene (ATM). Sequen cing this region from various individuals demonstrated two different polymo rphic repeating units adjacent to one another. The fact that the sequence i s located within the ATM gene provides a unique opportunity to follow segre gation of affected and unaffected haplotypes for prenatal diagnosis of atax ia-telangiectasia. The high degree of polymorphism observed with this marke r will also aid in evaluating loss of heterozygosity (LOH) across this regi on of the genome and may prove valuable in assessing the role of the ATM ge ne in susceptibility to cancer. Am. J. Med. Genet. 82:287-289, 1999. (C) 19 99 Wiley-Liss, Inc.