Four pairs of monozygotic twins with FAP-I
| Origin | Indonesia22 | Sweden23 | Majorca | Portugal |
|---|---|---|---|---|
| Sex | Female | Male | Male | Male |
| Symptoms of FAP-I | Both | Only one | Both | Both |
| Difference in onset age (y) | 4 | ? (>7) | 12 | 4 |
| Different clinical expression: | Yes | NA | Yes | Yes |
| in sensorimotor syndrome | Yes | NA | Yes | Yes |
| in digestive disturbances | Yes | NA | Yes | Yes |
| in renal involvement | Yes | NA | Yes | NP |
| in vitreous deposits | NP | NA | Yes | NP |
| in cardiac involvement | Yes | NA | NP | Yes |
| Probability of monozygosity | Presumed | Presumed | 99.03% | 99.99% |
NA=not applicable (only one affected); NP=not present in any.