Probability of having low VWF levels in parents and offspring given presence (VWD families) or absence (healthy families) of a disease gene transmitted as an autosomal dominant trait
| . | Probability of low VWF . | |
|---|---|---|
| Healthy families . | VWD families . | |
| First generation, parents | 1−Spec = 0.025 | Sens if carrier = 0.80; 1−Spec if not carrier = 0.025 |
| Second generation, offspring | 1−Spec = 0.025 | 0.5×Sens if carrier; 0.5×(1−Spec) if not carrier |
| Overall | 0.5×Sens + 0.5×(1−Spec) = 0.5×(1+Sens−Spec) = 0.4125 | |
| . | Probability of low VWF . | |
|---|---|---|
| Healthy families . | VWD families . | |
| First generation, parents | 1−Spec = 0.025 | Sens if carrier = 0.80; 1−Spec if not carrier = 0.025 |
| Second generation, offspring | 1−Spec = 0.025 | 0.5×Sens if carrier; 0.5×(1−Spec) if not carrier |
| Overall | 0.5×Sens + 0.5×(1−Spec) = 0.5×(1+Sens−Spec) = 0.4125 | |