It is interesting to see the topic of genetic mutation/flaws on the list while I am studying this stuff is school! From my understanding, the gene for Waardenburg is probably found where it influences many different traits including the white stripe, ruby eyes, and deafness. A trait is defined as being any one characteristic and one gene can effect many traits (pleiotropic). This would explain why all of the above traits are not necessarily found together all the time. In genetics, there is no such thing as a flaw. There is only the expression of a gene in the phenotype (what you see). Some traits may be more desirable to us, but the fact that the trait persists means that there may be something else that it effects that is good! This set of traits is not a mutation. A mutation is a process that happens to cause a chromosome to have genetic material not present in either of the two parents that gave rise to the mutated egg or sperm. Since this set of traits is passed from parent to child, it is present (perhaps unexpressed) in one parent or both parents. It is in the set of possible color patterns for the offspring. If a new color pattern emerges, like green, that could be a possible mutation that expressed as a dominant allele (one of a set of possible color patterns). What I don't know is if the gene is dominant or recessive, this would only be proved by breeding two ferrets affected by Waardenburg to each other. If all of the kits have some expression of the disorder, it is probably recessive, and if they do not, probably dominant. If the two parents both had two genes for Waardenburg and were bred to each other, the kits would still have expression of these traits even if the gene was dominant. This type of experiment would be hard to do and would require an extensive pedigree of all of the ferrets involved and the history of Waardenburg in the lines. I would argue that because of the prevelence of this set of traits in many different species, the trait may have been around since the beginning of mammals at all! (Bob C.?) Any (polite) comments or questions would be welcomed! Rachel [Posted in FML issue 2576]