If you are a parent and a smoker, your children’s DNA may be affected, even if you quit smoking before conception. Adam de Smith an associate researcher at the University of California, San Francisco, has found that prenatal smoking by either parent can cause what’s called a genetic deletion in their children.De Smith: The researchers looked at the gene deletions in the immune system, which can cause acute lymphoblastic leukemia, the most common type of childhood cancer. “Thankfully, nowadays cure rates are upwards of 85-90 percent. Even though they have survived the cancers, they go on to health issues in later life. For example, increase risks of heart disease, pulmonary disease and also increased secondary cancer rates. Ideally, we would like to prevent childhood leukemia in the first place.” ]