what could be the cause,(perharps a mutation)of parents with normal black hair colour to maybe after their middle age years,having a child who has just lived 4 like 20years and have started to develop white or grey hairs in the head and chin?what can such a trait be linked to?
Does not need to be a recent mutation. The genes for early greying of hair might have been floating about in the population for a very long time, but just come together (becoming homozygous) on rare occasions.
This thread has been unanswered for a couple of months now but such interesting topic should be known by the new members of these forum, so I have decide to make it alive again. Instead of creating a new thread and also to avoid duplicate post, i have posted my opinion to the old one. (pardon to the board if what i did was wrong).
The change in hair color (on biological definition) can be caused by two factors: age and genetics. Study shows that hair follicle has “melanogenesis clock”, it slows down or stop the melanocyte activity that causes the hair to be gray.