Genetics is the branch of biology that deals with the coded units of information (genes) that we pass from one family member to another. Genes influence how our bodies grow, how we look, and how we learn. Health or learning problems can result from changes in our genes (mutations). Some of these medical conditions can be inherited. The knowledge of the inheritance of specific traits is important if medical, educational or family planning decisions need to be made.

If you have one of the following situations, your doctor may recommend a genetic evaluation:

• You have a child who has birth defects, unique physical features, significant learning problems, mental retardation or developmental delays.
• You think there may be an inherited health problem in your family or your partner's family.
• You are pregnant and your baby is at risk for a genetic disorder based on your age, your ethnic background, an abnormal prenatal screening blood test or an abnormal ultrasound finding.
• You are pregnant, and your baby may be affected by an illness you have or had (such as diabetes, viruses, high fevers) or by something you were exposed to (such as medications, drugs, alcohol, chemicals).
• You have been told your child has or may have a chromosomal abnormality or another specific genetic condition.
• You have had two or more unexplained miscarriages.
• You or a close family member has a disease that has a genetic cause, such as sickle cell anemia, cystic fibrosis or muscular dystrophy.
• You or a close family member has a condition that seems to run in the family, such as certain cancers, heart disease or mental illness.