Diagnostics of Mendelian diseases require distinguishing mutations with drastic effects from other human variation ... 2 should be used to evaluate rare alleles at loci potentially involved ...
"The analysis identified low frequency mutations in the hemagglutinin gene ... "While these low frequency changes are rare in humans, they have been reported in previous cases of A(H5N1) in ...
Unique mutations in the H5N1 strain enhance replication in human cells and cause severe disease in mice. The virus has spread from birds to mammals, including dairy cows, and infected humans ...