What is the cause of my birth malformation? Why doesn't my brother have it, too?

Many children are born with some sort of physical malady and other siblings are not. it's very common. I am one of 12 children. I was born with a rare pancreas disease for which I had 8 hrs surgery as an adult with plastic tubes etc. None of my siblings were born with this, my parents have no history of this either. Some where in our genetics line, someone was suffering with this and I received that nasty recessive gene. Your mom's age has no bearing on the births. Women have been know to give birth a lot later in life. My mom was 42 when the last child was born. Look at this way, you're unique, I know you don't like it but it makes you special. Kicking your mom's abdomen also would have no bearing on this. The fetus is so protected by amniotic fluid, the most that would have happened was a floating around and like you said. a 7 yr. old kicking, I'm sure it wasn't hard. No, I don't believe this could have been prevented. Your mom is not at fault nor your dad. it's just a fluke of nature and you are among very special and unique people. Not something I want to claim fame for, but I too am like you. I don't wonder why though. I've accepted it. I will say this,,,I also had an identical twin. She died shortly after birth. Go figure.