The objective of this investigation is to test the hypothesis of the possible association of one or more microsatellites located on 425-4933 with NSCLP. In this study a sample of 51 extended pedigrees were analyzed. From these pedigrees a sample of 51 caseparents trios was obtained. A novel genetic analysis was carried out using the Extended Transmission Disequilibrium Test (ETDT). Also a case control study was carried out with the 51 probands of the case-parents trios plus a sample of 94 controls of the Chilean population to test if differences were observed resulting from the methods used for the association studies. Microsatellites D4S1570, D4S1615, FGA, UCP1 and D4S1597 located in 4q were analyzed. The polymerase chain reaction (PCR) was used for analysis of DNA. Forward primers were marked with fluorescent-dye-label. Electrophoresis and analyses were carried out in an ABI PRISM 377 ...