[The Duffy blood group system in the determination of paternity].

Authors report in detail recent achievments the investigation of Duffy's blood group system. Genetics of the system is shortly reviewed. Results of their own population-genetical investigation--carried out on 723 non-related persons by the aid of anti-Fy(a) and anti-Fy(b) serum--are also described. According to the author's data frequency of the phenotype Fy(a+b-)=19,63%, of the phenotype Fy(a+b)=50,91%, and of the phenotype Fy(a-b+)=29.46%. Data of the gene-frequency: Fya=0,451; Fyb=0,549. Presence of the gene Fy(-) was not revealed. The Duffy system--among others--was examined in 299 cases of discussed paternity. In 30 cases (10.3%) paternity was excluded on the base of it. In 31 men (8.29%) out of 374 the paternity cystem. Maximal (theoretical) chance of exclusion calculated from the data got in own investigations: 18.625%. Examined and calculated values of the chance of exclusion in cases of opposed homozygotes (12.26%) and in cases of the lack of characteristics (6.36%) were similar to a suitable degree. Technical problems of the investigation are further discussed. Author recommend the use of the examination of Duffy system in cases of discussed paternity.