Dataset Information

Mutations of the SYCP3 gene in women with recurrent pregnancy loss.

ABSTRACT: Aneuploidy, a chromosomal numerical abnormality in the conceptus or fetus, occurs in at least 5% of all pregnancies and is the leading cause of early pregnancy loss in humans. Accumulating evidence now suggests that the correct segregation of chromosomes is affected by events occurring in prophase during meiosis I. These events include homologous chromosome pairing, sister-chromatid cohesion, and meiotic recombination. In our current study, we show that mutations in SYCP3, a gene encoding an essential component of the synaptonemal complex that is central to the interaction of homologous chromosomes, are associated with recurrent pregnancy loss. Two out of 26 women with recurrent pregnancy loss of unknown cause were found to carry independent heterozygous nucleotide alterations in this gene, neither of which was present among a group of 150 fertile women. Analysis of transcripts from minigenes harboring each of these two mutations revealed that both affected normal splicing, possibly resulting in the production of C-terminally mutated proteins. The mutant proteins were found to interact with their wild-type counterpart in vitro and inhibit the normal fiber formation of the SYCP3 protein when coexpressed in a heterologous system. These data suggest that these mutations are likely to generate an aberrant synaptonemal complex in a dominant-negative manner and contribute to abnormal chromosomal behavior that might lead to recurrent miscarriage. Combined with the fact that similar mutations have been previously identified in two males with azoospermia, our current data suggest that sexual dimorphism in response to meiotic disruption occurs even in humans.

SUBMITTER: Bolor H

PROVIDER: S-EPMC2668043 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mutations of the SYCP3 gene in women with recurrent pregnancy loss.

Bolor Hasbaira H Mori Terumi T Nishiyama Sachie S Ito Yoshimasa Y Hosoba Eriko E Inagaki Hidehito H Kogo Hiroshi H Ohye Tamae T Tsutsumi Makiko M Kato Takema T Tong Maoqing M Nishizawa Haruki H Pryor-Koishi Kanako K Kitaoka Eri E Sawada Tomio T Nishiyama Yukio Y Udagawa Yasuhiro Y Kurahashi Hiroki H

American journal of human genetics 20081224 1

Aneuploidy, a chromosomal numerical abnormality in the conceptus or fetus, occurs in at least 5% of all pregnancies and is the leading cause of early pregnancy loss in humans. Accumulating evidence now suggests that the correct segregation of chromosomes is affected by events occurring in prophase during meiosis I. These events include homologous chromosome pairing, sister-chromatid cohesion, and meiotic recombination. In our current study, we show that mutations in SYCP3, a gene encoding an ess ...[more]

PMID: 19110213

Similar Datasets

Project description:Pregnancy loss is the most common complication of human pregnancy. Recurrent early pregnancy loss (REPL) has multiple etiologies, including endometrial dysregulation leading to “suboptimal” implantation. Although the implantation process is tightly regulated in Eutherian (placental) mammals, the molecular factors contributing to dysregulated endometrial gene expression patterns in women with REPL are largely unknown. We hypothesized that genes that gained novel expression in the endometria of mammals that evolved in the Eutherian stemlineage, coincident with the evolution of pregnancy, are likely essential for establishment and maintenance of normal pregnancy and are, therefore, good candidates for genes whose expression may be dysregulated in disorders such as REPL. To test this hypothesis, we took an evolutionary forward genomics approach to characterize gene expression profiles of midsecretory endometria from women with REPL associated with abnormal endometria based either on histology or molecular expression of cyclin E. We identified 58 genes that were differentially expressed (P<0.001) between women with out-of-phase histological dating vs normal histology, and 81 genes that were differentially expressed (P<0.001) between women with abnormally elevated cyclin E levels vs normal cyclin E. Remarkably, genes that were recruited into endometrial expression during the evolution of pregnancy in Eutherian mammals were significantly enriched for dysregulated genes (P=0.002 for histology, P=0.021 for cyclin E), as well as for immune and signaling pathways with essential roles in endometrial biology. Thus, our novel evolutionary-based forward genomics approach identified genes whose dysregulation during the mid-secretory phase likely contributes to the molecular etiologies of recurrent early pregnancy loss. Total RNA obtained from mid luteal phase endometrium (two replicates per biopsy) from women with recurrent early pregnancy loss (REPL). Endometrial gene expression levels were compared 1) between women with out-of-phase (n=10) and normal histological dating (n=22), 2) between women with abnormally elevated (n=9) and normal (n=23) cyclin E levels. For 5 additional women with abnormally high cyclin E levels, biopsy samples were collected before and after progesterone treatment to investigate the gene expression profiles in response to progesterone.

Project description:Study questionAre mutations in NLRP2/7 (NACHT, LRR and PYD domains-containing protein 2/7) or KHDC3L (KH Domain Containing 3 Like) associated with recurrent pregnancy loss (RPL) or infertility?Summary answerWe found no evidence for mutations in NLRP2/7 or KHDC3L in unexplained RPL or infertility.What is known alreadyMutations in NLRP7 and KHDC3L are known to cause biparental hydatidiform moles (BiHMs), a rare form of pregnancy loss. NLRP2, while not associated with the BiHM pathology, is known to cause recurrent Beckwith Weidemann Syndrome (BWS).Study design, size, and durationNinety-four patients with well characterized, unexplained infertility were recruited over a 9-year period from three IVF clinics in Sweden. Blood samples from 24 patients with 3 or more consecutive miscarriages of unknown etiology were provided by the Recurrent Miscarriage Clinic at St Mary's Hospital, London, UK.Participants/materials, setting, methodsPatients were recruited into both cohorts following extensive clinical studies. Genomic DNA was isolated from peripheral blood and subject to Sanger sequencing of NLRP2, NLRP7 and KHDC3L. Sequence electropherograms were analyzed by Sequencher v5.0 software and variants compared with those observed in the 1000 Genomes, single nucleotide polymorphism database (dbSNP) and HapMap databases. Functional effects of non-synonymous variants were predicted using Polyphen-2 and sorting intolerant from tolerant (SIFT).Main results and the role of chanceNo disease-causing mutations were identified in NLRP2, NLRP7 and KHDC3L in our cohorts of unexplained infertility and RPL.Limitations, reasons for cautionDue to the limited patient size, it is difficult to conclude if the low frequency single nucleotide polymorphisms observed in the present study are causative of the phenotype. The design of the present study therefore is only capable of detecting highly penetrant mutations.Wider implications of the findingsThe present study supports the hypothesis that mutations in NLRP7 and KHDC3L are specific for the BiHM phenotype and do not play a role in other adverse reproductive outcomes. Furthermore, to date, mutations in NLRP2 have only been associated with the imprinting disorder BWS in offspring and there is no evidence for a role in molar pregnancies, RPL or unexplained infertility.Study funding/competing interestsThis study was funded by the following sources: Estonian Ministry of Education and Research (Grant SF0180044s09), Enterprise Estonia (Grant EU30020); Mentored Resident research project (Department of Obstetrics and Gynecology, Baylor College of Medicine); Imperial NIHR Biomedical Research Centre; Grant Number C06RR029965 from the National Center for Research Resources (NCCR; NIH). No competing interests declared.

Dataset Information

Mutations of the SYCP3 gene in women with recurrent pregnancy loss.

Publications

Mutations of the SYCP3 gene in women with recurrent pregnancy loss.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets