Genfrequenzen und Vererbung im Duffy-System

Summary Genotyping in the Duffy-system was carried out using special combined trypsin-antiglobulin-techniques. The heterozygous presence of the third allele Fy was estimated by the single dose of the antigen Fy^a or Fy^b, whereas the homozygous types Fy^aFy^a or Fy^bFy^b gave the double-dosage-effect.Genotyping on 1408 unrelated persons in Hesse gave the following gene frequencies: Fy^a=0.4251; Fy^b=0.5582; Fy=0.0167. Expected and observed values showed a good correspondence (p0.72 for 4 d.f.).In phenotyping of 3768 persons, the very rare type Fy (a-b-) was found only once, which is in good agreement with the calculated gene frequency of Fy.Among those genotyped, family studies were subsequently done on 22 selected propositi. In the 13 cases in which the propositus had the third allele in the heterozygous state, the same third allele was again found at least once in the family where the propositus was a child (7x). Where the propositus was a parent (6x), the third allele was also found three times in the children; this allele was not transmitted in only 3 families with 4 children. In contrast, we did not find a single Fy-gene in the 8 families where the propositus was Fy^aFy^a or Fy^bFy^b.Finally, phenotyping was done in 283 unselected families. In this group, genotyping was restricted to those cases in which the distribution of Duffy-phenotypes suggested the presence of the third allele. In both groups of families not a single case of contradiction against the hereditary rules was observed.The reliability of genotyping is discussed, as well as its importance for anthropological studies and paternity cases.

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Direktor: Profl Dr. W. Spielmann

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.