[RRAdam]

Did you know that MPB is not necessarily linked to your mothers side of the family? (ie if her grandfather suffered from mpb, you likely will to) It is not a sex linked trait like many people think, but a sex limited trait. The mpb gene is carried on a autosomal gene independant of sex. Either the father or the mother can carry it. It acts as a dominant gene in males, so if any part of the gene carrys the mpb allele, you will suffer from mpb. The gene is recessive in females, so it may or may not be apparent on that side. However, if your mother suffers from mpb (which some women do) you will have the gene passed on you no matter what since she has a homozygous gene. The gene itself is activated by testosterone (and as a result, dht) hence the term, sex limited trait.

So just because you dont see it running in your mothers side doesnt mean you are not going to be affected - your father can pass it to you as well.