Documentation

Every child inherits one allele from each of its two parents. For each blood group system, we check that there is at least one combination where one allele comes from the mother and the other from the alleged father. If no combination is possible, paternity is excluded on that system.

ABO (alleles A, B, O), Rhesus (D dominant / d recessive) and, optionally, Kell (K dominant / k recessive). The Kell system is only taken into account if it is provided for all three people.

Paternity is excluded as soon as at least one system is incompatible. Conversely, compatibility across all systems does not prove paternity: it only means it cannot be excluded by these blood groups.

Before any analysis, the app checks the consistency between mother and child (for example, an O mother cannot have an AB child). In case of inconsistency, the input is flagged rather than wrongly attributed to the father.

The model is phenotypic and simplified (rare subgroups and variants are not modelled). BioPaternal is an educational, first-line orientation tool, never a proof. Confirmation by a DNA test remains essential.