| Pattern | Definition |
| Syndrome | Pattern of anomalies that occur together and are associated with a set number of signs and symptoms |
| Sequence | Pattern of anomalies in which a single known defect in development causes a cascade of subsequent abnormalities |
| Field defect | Pattern of anomalies caused by disturbance of a developmental field (a region of the embryo that develops in a contiguous physical space) |
| Association | Two or more anomalies that are not pathogenetically related and occur together more frequently than expected by chance |
