title: Correlation between the allelic distribution of STRs in a Finnish population and phenotypically different gastrointestinal tumours: a study using four X-chromosomal markers (DXS7423, DXS8377, ARA, DXS101).
abstract: Microsatellite instability in tumours has been suggested as a model to study the process of short tandem repeat (STR) mutations. In the present study we have determined the allelic variation of four X-STRs (DXS7423, DXS8377, DXS101 and ARA) in a Finnish population of 103 individuals, and assessed whether a comparable allelic distribution could be found in a series of gastrointestinal cancers differing by the level of microsatellite instability. Fifty-seven gastric and colorectal cancers were stratified by autosomal STRs, and the mononucleotide marker BAT-26 into stable, low-level unstable and high-level unstable microsatellite (MSI-H) cancers, of which the last produced the majority of X-STR alleles. For the four markers analysed, a significant correlation of allele distribution between our Finnish population sample and MSI-H tumours was noted. Together, the eight MSI-H tumours found represented 80%, 66-80% and 100% of the DXS101 alleles in the Finnish, and in previously described Caucasian and Korean population samples, respectively. Of the ARA, DXS7423 and DXS8377 alleles in the Finnish population, 42%, 75% and 79% were found in the MSI-H cancers, respectively. The results suggest that analysis of STR variation in a relatively small number of MSI-H cancers may aid in pre-evaluation of their allelic distribution in a population.
authors.affiliation: Laboratory of Forensic Biology, Department of Forensic Medicine, University of Helsinki, Kytösuontie 11, P.O. Box 40, 00014 Helsinki, Finland. hanna.vauhkonen@helinksi.fi
authors.forename: H
authors.initials: H
authors.lastname: Vauhkonen
authors.forename: M
authors.initials: M
authors.lastname: Vauhkonen
authors.forename: P
authors.initials: P
authors.lastname: Sipponen
authors.forename: A
authors.initials: A
authors.lastname: Sajantila
mesh_terms: D000483:Alleles; D041321:Chromosomes, Human, X; D005387:Finland; D005770:Gastrointestinal Neoplasms / Q000145:classification / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D010641:Phenotype; D020080:Tandem Repeat Sequences
chemical_list: D005819:Genetic Markers