Aims:: The ductal plate abnormality of the liver in fetuses with the Meckel‐Gruber syndrome has been well characterised, but its aetiology remains unknown. We have analysed liver structure in six fetuses with this syndrome, using routine histology, immunocytochemistry, and electron microscopy.
Methods:: Liver tissue from six fetuses of 11–27 weeks gestational age was examined by immunoperoxidase staining with antigens to cyokeratin (AE1/3) and polyclonal CEA. We also examined the ultrastructure of the syndromic fetal liver. The findings were compared with livers of control fetuses obtained from miscarriages, of similar size and gestational age but without dysmorphic features or developmental anomalies.
Results:: The ductal plate abnormality was present in all the fetuses with the Meckel‐Gruber syndrome. There were abnormalities of biliary excretion in all syndromic fetuses. Ultrastructural studies of the portal tract revealed abnormal collagen bundles in the Meckel‐Gruber syndrome.
Conclusions:: Our findings, in conjunction with other reports in the literature, suggest that the ductal plate abnormality may be caused by failure of anastomosis of the intra‐ and extrahepatic biliary systems, perhaps in association with abnormalities of the portal tract stroma and biliary excretion.