If one sibling had men II could another sibling have men I or is it unlikely?

Genetic counseling. Both men1 & men2 are autosomal dominant, containing a 50:50 chance, if both parents have men. To know definitively, one would need to obtain a prenatal genetic assessment. Each child is 50% mom and 50% dad. If one parent has men and the other does not, child has 25% chance of having men. However, grandparents genes also important. So for the true answer see a geneticist.