Hereditary illness and kamma

Many physical and mental illnesses are genetic or hereditary, whether partially or completely, the contributing factor is genetic, nevertheless. For example, you are born into a family that has genetic illness e.g. anxiety disorder, compulsive disorder, cancer, diabetes, to name a few. The question is, since genetic or hereditary illness will then pass down to your children. If you get married and have children, as parents, are you doing bad kamma?