Facts
This case was about the determination of paternity. The plaintiff X. sued the defendant Y. for the establishment of paternity. The Federal Court had to assess whether, based on the results of a serological examination, the paternity of the defendant could be excluded with a probability bordering on certainty.
The Federal Court obtained an expert opinion from Professor Dr. R. Bütler from the Central Laboratory of the Swiss Red Cross Blood Donation Service. He stated that population genetic studies had fully confirmed the mode of inheritance for the extended Gc system. An exclusion of paternity according to this method could be attributed the predicate of "probability bordering on certainty", corresponding to a reliability of at least 99.8 percent.
Also for the HLA (A, B, C) system, the maximum probability of error in formulating an exclusion according to the first rule of inheritance was less than 0.2 percent, so the result could be stated as "paternity apparently impossible". Provided that there were no interfering cross-reactions in the case concerned, an HLA (A, B, C) exclusion of paternity could also be attributed the predicate of "probability bordering on certainty".
Considerations
The Federal Court concluded that the presumptive father was excluded as the progenitor of child X. by both the extended Gc system and the HLA system, according to the…