Generalised Bayesian analysis for autosomal recessive disease with one risk factor and no identifiable mutation (scenario 8)*
| Variable | Generalised Bayesian analysis variables | |||||
|---|---|---|---|---|---|---|
| *No detectable mutation has been found in the fetus. One of the parents (Parent A) has one detectable mutation, and the other parent (Parent B) has not been tested. See explanation in the text. Note differences from Table 8 | ||||||
| Prior probability of parent B | ||||||
| Carrier (Db+N) | y | |||||
| Non-carrier (N+N) | 1−y | |||||
| Conditional probabilities | ||||||
| Fetus (mutation) | ||||||
| Affected (Da+Db) | 0.25 | |||||
| Carrier (Da+N) | 0.25 | 0.5 | ||||
| Carrier (Db+N) | 0.25 | |||||
| Non-carrier (N+N) | 0.25 | 0.5 | ||||
| Risk factor number 1 (that is, echogenic bowel) | a | b | b | b′ | b | b′ |
| One allele with no mutation detected | ||||||
| Da | 0 | 0 | 0 | |||
| Db | 1−d | |||||
| N | 1 | 1 | ||||
| The other allele with no mutation detected | ||||||
| Db | 1−d | |||||
| N | 1 | 1 | 1 | 1 | 1 | |
| Joint probability | 0 | 0 | 0.25by(1−d) | 0.25b′y | 0 | 0.5b′(1−y) |
| Column | A | B | C | D | E | F |