No abstract

Meckel-Gruber syndrome (MKS) is an autosomal recessive lethal malformation syndrome characterized by renal cystic dysplasia, central nervous system malformations (typically, posterior occipital encephalocele), and hepatic developmental defects. Two MKS genes, MKS1 and MKS3, have been identified recently. The present study describes the cellular, sub-cellular and functional characterization of the novel proteins, MKS1 and meckelin, encoded by these genes. In situ hybridization studies for MKS3 in early human embryos showed transcript localizations in agreement with the tissue phenotype of MKS patients. Both MKS proteins predominantly localized to epithelial cells, including proximal renal tubules and biliary epithelial cells. MKS1 localized to basal bodies, while meckelin localized both to the primary cilium and to the plasma membrane in ciliated cell-lines and primary cells. Meckelin protein with the Q376P missense mutation was unable to localize at the cell membrane. siRNA-mediated reduction of Mks1 and Mks3 expression in a ciliated epithelial cell-line blocked centriole migration to the apical membrane and consequent formation of the primary cilium. Co-immunoprecipitation experiments show that wild-type meckelin and MKS1 interact and, in three-dimensional tissue culture assays, epithelial branching morphogenesis was severely impaired. These results suggest that MKS proteins mediate a fundamental developmental stage of ciliary formation and epithelial morphogenesis.

Please cite this paper as: Heazell A, McLaughlin M, Schmidt E, Cox P, Flenady V, Khong T, Downe S. A difficult conversation? The views and experiences of parents and professionals on the consent process for perinatal postmortem after stillbirth. BJOG 2012;119:987–997. Objective  To describe the experiences, knowledge and views of both parents and professionals regarding the consent process for perinatal postmortem. Design  Internet‐based survey. Setting  Obstetricians, midwives and perinatal pathologists currently working in the UK. Parents who have experienced a stillbirth in the UK in the previous 10 years. Sample  Obstetricians, midwives and perinatal pathologists registered with their professional bodies. Parents who accessed the Sands website or online forum. Methods  Online self‐completion questionnaire with both fixed‐choice and open‐ended questions. Results  Responses were analysed from 2256 midwives, 354 obstetricians, 21 perinatal pathologists and 460 parents. The most common reason for parents to request postmortem examination was to find a cause for their baby’s death; the prevention of stillbirths in others also ranked highly. Perinatal pathologists possessed greatest knowledge of the procedure and efficacy of postmortem, but were unlikely to meet bereaved parents. The majority of professionals and parents ranked emotional distress and a lengthy wait for results as barriers to consent. The majority of staff ranked workload, negative publicity, religion and cultural issues as important barriers, whereas most parents did not. Almost twice as many parents who declined postmortem examination later regretted their decision compared with those who accepted the offer (34.4 versus 17.4%). Conclusion  Emotional, practical and psychosocial issues can act as real or perceived barriers for staff and bereaved parents. Education is required for midwives and obstetricians, to increase their knowledge to ensure accurate counselling, with due regard for the highly individual responses of bereaved parents. The contribution of perinatal pathologists to staff education and parental decision‐making would be invaluable.

Multiple pterygium syndromes (MPSs) comprise a group of multiple-congenital-anomaly disorders characterized by webbing (pterygia) of the neck, elbows, and/or knees and joint contractures (arthrogryposis). In addition, a variety of developmental defects (e.g., vertebral anomalies) may occur. MPSs are phenotypically and genetically heterogeneous but are traditionally divided into prenatally lethal and nonlethal (Escobar) types. To elucidate the pathogenesis of MPS, we undertook a genomewide linkage scan of a large consanguineous family and mapped a locus to 2q36-37. We then identified germline-inactivating mutations in the embryonal acetylcholine receptor gamma subunit (CHRNG) in families with both lethal and nonlethal MPSs. These findings extend the role of acetylcholine receptor dysfunction in human disease and provide new insights into the pathogenesis and management of fetal akinesia syndromes.

Immune tolerance during human pregnancy is maintained by a range of modifications to the local and systemic maternal immune system. Lymphoid infiltration is seen at the implantation site of the fetal-maternal interface, and decidual NK cells have been demonstrated to facilitate extravillous trophoblast invasion into maternal decidua during the first trimester, optimizing hemochorial placentation. However, although there is considerable T cell infiltration of the maternal decidua, the functional properties of this T cell response remain poorly defined. We investigated the specificity and regulation of CD4 and CD8 T cells obtained from human third trimester decidua and demonstrated that decidual CD4 and CD8 T cells exhibit a highly differentiated effector memory phenotype in comparison with peripheral blood and display increased production of IFN-γ and IL-4. Moreover, decidual T cells proliferated in response to fetal tissue, and depletion of T regulatory cells led to an increase in fetal-specific proliferation. HY-specific T cells were detectable in the decidua of women with male pregnancies and were shown to be highly differentiated. Transcriptional analysis of decidual T cells revealed a unique gene profile characterized by elevated expression of proteins associated with the response to IFN signaling. These data have considerable importance both for the study of healthy placentation and for the investigation of the potential importance of fetal-specific alloreactive immune responses within disorders of pregnancy.