Lewis genotyping by the PCR-RFLP method in a Japanese population and its evaluation in forensic analysis.

Lewis phenotyping of red blood cells has many problems such as the influence of many biological conditions, the change during the period from newborn to early childhood and mistyping by non-specific anti-Lewis antibodies. Therefore, it would be useful to determine the Lewis genotype. Recently a method of Le-genotyping by PCR-RFLP was established. We determined the frequencies of Lewis genotypes in a Japanese population and discuss the applicability to paternity tests and other forensic applications. The gene frequencies of Le, le1 and le2 in the Japanese population studied were 0.7032, 0.2358 and 0.0610 respectively. Out of 12 paternity cases where paternity was excluded by other markers, 3 alleged fathers could also be excluded by Lewis genotyping. The genotype from organs of a fetus from a 3-month pregnancy was Le/Le. The determination of Lewis genotypes could play a useful role as a genetic marker in paternity tests and forensic analyses.