Genes are part of chromosomes inside your body’s cells. They store instructions and are the building blocks for how your body grows and works. Genes are passed from parents to children. About 20% of birth defects are caused by genetic or hereditary factors.
Birth defects are common. Between 2% and 3% of infants have one or more defects at birth. That number increases to 5% by age one (not all defects are discovered directly after your child’s birth). Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, in how the body develops or in how the body works.