Investigation of ACTBP2 mutations in the Japanese population

In the investigation of ACTBP2 (human beta-actin related pseudogene H-beat-Ac-psi-2) mutation in the Japanese population, 230 meioses were analyzed, and two cases of paternal mutations were observed. Paternity confirmation analyses were carried out using seventeen genetic marker systems including erythrocyte antigens, HLA types, D1S80, and nine STR loci contained in the AmpFlSTR Profiler Kit. Excluding ACTBP2, the paternity probabilities for the two cases were each calculated to be over 99.99%. Genotyping of the ACTBP2 locus was performed using the fluorescence detection method under denaturing conditions on an ABI PRISM 310 Genetic Analyzer. After sequencing analysis using the BigDye terminator method, the paternally originated alleles of the two children were found in one case to show one repeat insertion and in the other case one repeat deletion as compared with each father. Although the number of meioses observed in this study is limited, it appears that ACTBP2 mutations are not rare events in the Japanese population.