Small, unofficial, white populations can be found thoughout the Middle East and North Africa. Just as small, unofficial, Semetic groups can be found thoughout Southern Europe. No way of knowing how large these respective populations truely are.
What we do know, however, is that if a person has dominate genes then those traits always show. However, it is possible for recessive traits to remain dormant for centuries. A child with two dark parents could be born with blond hair and blue eyes, the opposite is impossible. There exists a fair amount of recessive decent in North Africa / Middle East that occasionally pops up.