Only 1 second-degree relative (or more distantly related relative) affected
1 first-degree relative with disease onset at an average age
or
2 affected second-degree relatives on the same side of the family
Premature disease or unusual presentation in a first-degree relative
or
2 or more first-degree relatives on the same side of the family affected
or
2 or more second-degree relatives on the same side of the family affected, with at least 1 having premature disease onset
or
3 or more affected on the same side of the family
or
Moderate-risk status on both sides of the family
Family history-based risk estimation applies to common, autosomal dominant conditions in adults. Estimations for autosomal recessive and X-linked conditions differ. There are also significant disease-dependent definitions in risk estimation and possible effects of external factors that influence risk, such as diet, smoking, and alcohol use for certain cancers and cardiovascular disease. Refer to UpToDate topics on genetic counseling, genetic testing, and specific conditions for further information and risks associated with those conditions.