Familial aggregation of preeclampsia and intrauterine growth restriction in a genetically isolated population in The Netherlands.
Berends AL., Steegers EA., Isaacs A., Aulchenko YS., Liu F., de Groot CJ., Oostra BA., van Duijn CM.
Preeclampsia and intrauterine growth restriction are related, pregnancy-specific disorders with a substantial genetic influence, which may have a joint genetic aetiology. We investigated familial aggregation, consanguinity and parent-of-origin effects for preeclampsia and IUGR. Fifty women with previous preeclampsia and 56 with previous pregnancies complicated by intrauterine growth restriction were recruited from a recent genetically isolated population in the Netherlands. Their relationships were estimated by means of a large genealogy database that contains information on more than 110 000 individuals from the isolate over 23 generations. Relationships were quantified using kinship and inbreeding coefficients. Parent-of-origin effects were evaluated by comparing parental kinships. Eighty-six women (39 preeclampsia and 47 intrauterine growth restriction) could be linked to one common ancestor within 14 generations. The proportion of related women with previous preeclampsia (95.6%) or pregnancies complicated by intrauterine growth restriction (95.1%) was significantly greater than expected by chance (P<0.001). Combined analysis of both disorders did not change the magnitude of familial aggregation. The proportion of women born from consanguineous marriages was increased in women with previous preeclampsia (81.8%) and those with intrauterine growth restriction (78%) compared to a random sample (P<0.001). Maternal and paternal kinships were not significantly different in both disorders. We demonstrate cosegregation of preeclampsia and intrauterine growth restriction, supporting a common genetic aetiology. The high proportion of parental consanguineous marriages suggests the possibility of an underlying recessive mutation. No evidence was found for a parent-of-origin effect either in preeclampsia or in intrauterine growth restriction.