Nonsense mutation of EMX2 is potential causative for uterus didelphysis: first molecular explanation for isolated incomplete mullerian fusion
FERTILITY AND STERILITY
Authors: Liu, Shan; Gao, Xuan; Qin, Yingying; Liu, Wen; Huang, Tao; Ma, Jinlong; Simpson, Joe Leigh; Chen, Zi-Jiang
Abstract
Objective: To investigate the association between human empty spiracles homeobox 2 gene (EMX2) and incomplete mullerian fusion (IMF). Design: Case-control study. Setting: University-based hospital. Patient(s): Cohort of 517 clinically well-characterized IMF cases and 563 control women. Intervention(s): None. Main Outcome Measure(s): In cases and control women, direct sequencing of EMX2 exons and further functional studies; for functional studies, wild-type and mutant EMX2 expression plasmids constructed; human embryonic kidney cells (HEK293FT) transfected with empty vector, wild-type EMX2, mutant EMX2, and 1: 1 combination (wild-type/mutant plasmids) with additional functional studies performed to clarify the deleterious effect of the novel mutation detected. Result(s): A novel nonsense mutation p.E142X was detected in one woman with a didelphic uterus (1 of 517, 0.19%). The results of Western blot analysis confirmed that the mutation caused a truncated protein as predicted, and functional studies proved that it resulted in a dominant negative effect. Conclusion(s): The novel nonsense mutation we detected-EMX2, p.E142X-resulted in a dominant negative effect. The functional data were exemplified in HEK293FT cells. This reinforced the likelihood that EMX2 contributed to the pathophysiology of IMF. Although it is uncommon (0.19%), EMX2 is the first gene identified that if perturbed may cause isolated IMF. ((c) 2015 by American Society for Reproductive Medicine.)
Maternal plasma folate impacts differential DNA methylation in an epigenome-wide meta-analysis of newborns
NATURE COMMUNICATIONS
Authors: Joubert, Bonnie R.; den Dekker, Herman T.; Felix, Janine F.; Bohlin, Jon; Ligthart, Symen; Beckett, Emma; Tiemeier, Henning; van Meurs, Joyce B.; Uitterlinden, Andre G.; Hofman, Albert; Haberg, Siri E.; Reese, Sarah E.; Peters, Marjolein J.; Andreassen, Bettina Kulle; Steegers, Eric A. P.; Nilsen, Roy M.; Vollset, Stein E.; Midttun, Oivind; Ueland, Per M.; Franco, Oscar H.; Dehghan, Abbas; de Jongste, Johan C.; Wu, Michael C.; Wang, Tianyuan; Peddada, Shyamal D.; Jaddoe, Vincent W. V.; Nystad, Wenche; Duijts, Liesbeth; London, Stephanie J.
Abstract
Folate is vital for fetal development. Periconceptional folic acid supplementation and food fortification are recommended to prevent neural tube defects. Mechanisms whereby periconceptional folate influences normal development and disease are poorly understood: epigenetics may be involved. We examine the association between maternal plasma folate during pregnancy and epigenome-wide DNA methylation using Illumina's HumanMethyl450 Beadchip in 1,988 newborns from two European cohorts. Here we report the combined covariate-adjusted results using meta-analysis and employ pathway and gene expression analyses. Four-hundred forty-three CpGs (320 genes) are significantly associated with maternal plasma folate levels during pregnancy (false discovery rate 5%); 48 are significant after Bonferroni correction. Most genes are not known for folate biology, including APC2, GRM8, SLC16A12, OPCML, PRPH, LHX1, KLK4 and PRSS21. Some relate to birth defects other than neural tube defects, neurological functions or varied aspects of embryonic development. These findings may inform how maternal folate impacts the developing epigenome and health outcomes in offspring.