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 |