Demographics, phenotype, and genotype of monozygotic twin sets
| Twin group | Age (y) | Sex | Mutation | Age of onset (y) | Difference in age of onset (y) | Ref. No | Note |
| A1 | 41 | F | R122H | 5 | |||
| A2 | 41 | F | R122H | No | >36 | 6 | Discordant |
| G1 | 36 | F | N29I | 13 | |||
| G2 | 36 | F | N29I | No | >23 | 7 | Discordant |
| T1 | 24 | F | R122H | 16 | |||
| T2 | 24 | F | R122H | 14 | 2 | ||
| B1 | 8 | F | UNK | 3–5 | |||
| B2 | 8 | F | UNK | 3–5 | 0 | ||
| V1 | D | M | R122H | Childhood | |||
| V2 | D | M | R122H | No | 21 | Discordant | |
| C1 | 63 | F | UNK | 40 | |||
| C2 | 63 | F | UNK | ∼40 | 3–4 | PC | |
| F1 | 17 | F | NT | Infant | |||
| F2 | 17 | F | NT | Infant | 0 | 19 |
D, deceased; UNK, unknown gene; NT, not tested; PC, pancreatic cancer.