Generalised Bayesian analysis for autosomal recessive disease with one risk factor and no identifiable mutation (scenario 9)*
| Variable | Generalised Bayesian analysis variables | |||||
|---|---|---|---|---|---|---|
| *No detectable mutation found in fetus. One parent (parent A) has one detectable mutation; the other parent (parent B) has no detectable mutation. Note differences from table 11. | ||||||
| Prior probability of parentB | ||||||
| Carrier (Db+N) | y | |||||
| Non-carrier (N+N) | 1−y | |||||
| Test negative | 1−d | 1 | ||||
| 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 | |||||
| N | 1 | 1 | ||||
| The other allele with no mutation detected | ||||||
| Db | 1 | |||||
| N | 1 | 1 | 1 | 1 | 1 | |
| Joint probability | 0 | 0 | 0.25by(1−d) | 0.25b′y(1−d) | 0 | 0.5b′(1−y) |
| Column | A | B | C | D | E | F |