Could The Abnormal Birth Of Children Be Due To Inter Family Marriage?

Hi sir, I married my own aunty's son . My two baby died due to deficiency. Is this is the problem of relation marriage?
Babies born with enzyme deficiency. First I gave birth to boy baby ,he was abnormal and died after one year and after two more year I gave Birth to Girl baby but she also abnormal and died in few minutes after birth. Is this is any my(mum) deficiency?