Specimens were collected from unrelated apparently healthy males, blood donors from Equatorial Guinea (Central Africa). DNA was extracted from blood specimens using a bloodclean DNA purification Kit (Biotools) and typed in an ALF-Sequencer (Pharmacia). DYS19 alleles were determined according to protocols and allelic ladders kindly supplied by Peter de Knijff (1). Primers for DYS389I and DYS389II were synthesized according to Schultes et al. (2). PCR conditions for these two systems were modified as follows: a first denaturation step at 94°C 3 min; 5 cycles of 94°C 15 s, 58#x00B0;C 20 s, 72#x00B0;C 20 s, 34 cycles of 94#x00B0;C 15 s, 54#x00B0;C 20 s, 72#x00B0;C 20 s. Amplification products were typed with allelic ladders from our laboratory. Frequencies were calculated for all the systems through the gene counting method and gene diversity was estimated according to Nei (3).