Mrs O- I'd relax if I were you, genes pop up all over the place and produce the odd black sheep for example my daughter Sha'ori was born to me black hair blue eyes and my wife dark hair blue eyes and had chestnut red hair and eyes so dark they were practically black. More than one clever person implied she might not be mine, although I never doubted it for a moment, to the point where my wife gotso cross she got a DNA test done and sent the people concerned a copy- which revealed that she was in fact my daughter. Endless websites will even tell you that two blue eyed people can't have a black eyed child, but the fact is we did and upon closer inspection of sites that really know what they're talking about, oh yes it's perfectly possible. I would tell your brother not to worry, it's a cruel and stupid thing for people to say, either that or get a DNA test with one of the midget variety of your family to see if you are full siblings, but genes are fascinating and I'll bet there is nothing at all untoward, just stupid unkind people.