Analysis of different inheritance patterns in preeclampsia/eclampsia syndrome

Objective: To investigate how well various inheritance models would explain the familial tendency of the preeclampsia/eclampsia syndrome. Methods: The prevalence among seven groups of women with definite probabilities of exhibiting the disorder from six different family studies was used to obtain maximum likelihood estimates of the contributions to disease liability from major genes and multifactorial transmission. Results: Models involving a single major gene with incomplete penetrance or multifactorial inheritance offered considerably better fit to the observed data than no familial transmission at all or autosomal dominant and recessive inheritance models with complete penetrance. Of the major gene models, a dominant mode of transmission was preferred. From the extremes of the joint 95% confidence region for the gene frequency (p) and penetrance (f), the corresponding confidence limits for the best estimates were 0.06 < p < 0.16 and 0.38 > f > 0.23, respectively. Conclusions: These results indicate that the prevalence of the disease is not best explained by simple Mendelian inheritance as previously suggested. A major dominant gene model with reduced penetrance or multifactorial inheritance should be considered the best working hypotheses at present.