Why is HLA typing valuable in parentage testing?

HLA typing is particularly valuable in parentage testing due to the high degree of polymorphism associated with HLA alleles. This means that there are many different variations (or alleles) at the HLA loci within a population. This genetic diversity provides a robust system for distinguishing between individuals, making HLA typing a powerful tool when determining biological relationships.

In parentage testing, the ability to differentiate between alleles can indicate whether a child has inherited certain HLA alleles from their parents. Since each individual has a specific set of HLA alleles, the comparison of a child's HLA profile with those of potential parents can yield significant information. High polymorphism ensures that the likelihood of false inclusions or exclusions is minimized, thereby enhancing the reliability of the test results.

In context to the other options, while the number of loci and the number of alleles might appear relevant, they do not capture the essence of why HLA typing is effective for parentage testing. The classical Mendelian segregation is not a defining factor for its value in this testing, as HLA inheritance involves more complexity due to the broad range of alleles present. This further reinforces the pivotal role that high polymorphism plays in the utility of HLA typing for establishing parent