Linkage disequilibrium pattern in the L-myc gene in Italian and Japanese non-small-cell lung-cancer patients

Italian and Japanese non-small-cell lung-cancer patients were genotyped for an intragenic L-myc EcoRI restriction site polymorphism previously reporte d to be associated with lung-tumor prognosis in Asian populations but not i n Caucasians. Screening of the L-myc sequence in Italian samples allowed id entification of 2 additional 3'-UTR SNPs, located 2.3-3.0 kb from the EcoRI polymorphism, but no coding polymorphism was found. No significant associa tion was found between any of the 3 SNPs and lung-tumor prognosis in Italia n patients, consistent with the reported difference between Caucasian and A sian populations. Moreover, the newly discovered polymorphisms in the Itali an group were not present in Japanese patients. Significant LD between EcoR I and the 2 other SNPs was detected in the Italian population, whereas no s ignificant LD between the 2 3'-UTR markers was detected despite their close proximity (0.7 kb). Thus, the disparate conclusions about the role of L-my c polymorphism in tumor prognosis among different populations may rest in p opulation-specific LD between the functional gene and the L-myc polymorphis m. (C) 2001 Wiley-Liss, Inc.