Generalised Bayesian analysis for autosomal recessive disease with one risk factor and no identifiable mutation (scenario 5)*
| Variable | Generalised Bayesian analysis variables | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| *No detectable mutation found in fetus. Neither parent tested. | |||||||||
| Prior probabilities | |||||||||
| Parent A | |||||||||
| Carrier | x | ||||||||
| Non-carrier | 1−x | ||||||||
| Parent B | |||||||||
| Carrier | y | y | |||||||
| Non-carrier | 1−y | 1−y | |||||||
| Conditional probabilities | |||||||||
| Fetus (mutation) | |||||||||
| Affected (Da+Db) | 0.25 | ||||||||
| Carrier (Da) | 0.25 | 0.5 | |||||||
| Carrier (Db) | 0.25 | 0.5 | |||||||
| Non-carrier | 0.25 | 0.5 | 0.5 | 1 | |||||
| Risk factor number 1 (that is, echogenic bowel) | a | b | b | b′ | b | b′ | b | b′ | b′ |
| No mutation detected | (1−c) (1−d) | (1−c) | (1−d) | 1 | (1−c) | 1 | (1−d) | 1 | 1 |
| Joint probability | 0.25 axy (1−c) (1−d) | 0.25 bxy (1−c) | 0.25 bxy (1−d) | 0.25 b′xy | 0.5 bx (1−y) (1−c) | 0.5 b′x (1−y) | 0.5 by (1−x) (1−d) | 0.5 b′y (1−x) | b′ (1−x) (1−y) |
| Column | A | B | C | D | E | F | G | H | I |