Generalised Bayesian analysis for autosomal recessive disease with one risk factor and no identifiable mutation (scenario 6)*
| Variable | Generalised Bayesian analysis variables | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| *No detectable mutation has been found either in the fetus, or in one of the parents (parent A). The other parent (parent B) has not been tested. Note the differences from Table 8. | |||||||||
| Prior probabilities | |||||||||
| Parent A | |||||||||
| Carrier | x | ||||||||
| Non-carrier | 1−x | ||||||||
| Conditional probability | |||||||||
| Test negative | 1-c | 1 | |||||||
| 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 (echogenic bowel) | a | b | b | b′ | b | b′ | b | b′ | b′ |
| No mutation detected | (1−d) | 1 | (1−d) | 1 | 1 | 1 | (1−d) | 1 | 1 |
| Joint probability | 0.25 axy (1−c) (1−d) | 0.25 bxy (1−c) | 0.25 bxy (1−c) (1−d) | 0.25 b′xy (1−c) | 0.5 bx (1−y) (1−c) | 0.5 b′x (1−y) (1−c) | 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 |