I found a case in human. Daughter and mother have white patches on their skin (knees, belly and forehead exactly same location and shape) while her son has no such patches on his skin. Can anyone tell me whether it is an x-linked mutation?
From these data, we can not conclude. May be it's not genetic. It takes a precise diagnostic. After that, if the disease is known you can investigate candidates genes. Otherwise, there is a lot of work to identify the genes responsible, the transmission mode ...
thanks...I actually wish to know what is the probability that it is genetic mutation?? because the spots are permanent and of same shape and location and only in daughter and mother.
Assuming the father was wild type then if this was x-linked it would have to be a dominant x-linked trait with the mother and the daughter being heterozygous. It could be x-linked but until more is known about the family, especially the mother's parents before it can be determined for sure. Another key is the exact location of the spots, are they in a significant area, for example above the kidneys? If they are not I am personally doubtful it is x-linked. If it was we should see a more random development of the spots due to random x inactivation. It is possible but I personally do not think it is. Like Hadjkacem Basma said not enough is known to make a good prediction on the inheritance of it. Hope this helps.
thanks for the answer Gale.....no such spots has been found in the parents or grand parents. the mother of the child is the first one who got such spots. the spots are on three places. both knees, just above the belly button and center of the forehead. it was assumed that it was some sort of disease or anything else. the girl got married and her first son had no such spots, but when she gave birth to a daughter, it was surprising to see that the baby has exactly the same type of spots on her knees, above the bellybutton and forehead...that thing made me to ask the question..
disorder seems to be a case of vitiligo. as males are not affected so it is not a recessive X-linked case but it relies on pedigree analysis and phenotype to confirm whether it is dominant X-linked or a sporadic case