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Suspected causes of birth defects in humans.
| Suspected cause | % total |
|---|---|
| Genetic | |
| Autosomal genetic disease | 15–20 |
| Cytogenetic | 5 |
| Environmental | |
| Maternal conditions | 4 |
| Maternal infections | 3 |
| Mechanical problems (deformations) | 1–2 |
| Chemicals/drugs/radiation/hyperthermia | <1 |
| Preconception exposures | ? |
| Unknown (polygenic) | 65 |
