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Background Mild Isolated Ventriculomegaly affects 0.15–0.7% of pregnancies.1 The developmental prognosis for children seems to be better than that described for ventriculomegaly associated with other anomalies.2 But the risk of developmental delay is still unclear and presents a challenge to physicians for managing and counselling prospective parents. Aim To evaluate the prenatal management and prognosis of isolated mild cerebral ventriculomegaly. This is the first study on ventriculomegaly in Wales. Methods 63 cases of ventriculomegaly were reported from the healthboard to CARIS database with Hydrocephalus during 2003–2012. 35 were identified as isolated mild ventriculomegaly. 30 case notes were reviewed as 5 case notes could not be traced. Of the 30, 3 were lost to follow-up as they moved out of the area. Results 28 cases were diagnosed at second trimester anomaly scan, while one patient booked late at 28 weeks and in another the scan was normal at anomaly but developed later. 100% of women were screened for TORCH infection, all were negative for current infections. All women were offered amniocentesis, 9(30%) of them accepted, all 9 (30%) were normal karyotype. All women had scans every 4 weeks. Two women underwent termination due to progression of ventriculomegaly. In 17 (63%) cases of ventriculomegaly resolved in third trimester, it is difficult to asses the prognosis of these babies as they did not have cranial ultrasound or neurodevelopmental assessment routinely. Conclusions In our study all routine investigations including TORCH and karyotype are normal. 63% of the cases of mild isolated ventriculomegaly resolved in utero. It has highlighted the lack of uniform policy in neonatal assessment. There are limitations including the retrospective model, small sample size and not having the neonatal follow up. References Wax JR, Bookman BS, Cartin A, Pinette MG, Blackstone DO. Mild fetal cerebral ventriculomegaly: diagnosis, clinical associations and outcomes. Obstet and Gynaecol survey. 2003; 58(6):407–414 Mercier A, Eurin D, Mercier PY, Verspyck E, Marpeau L, Marret S. Isolated mild fetal cerebral ventriculomegaly: a retrospective analysis of 26 cases. Prenat Diagnosis 2001;21:589–595 Pilu G, Falco P, Gabrielli S, Perolo A, Sandri F, Bovicelli L. The clinical significance of fetal isolated cerebral borderline ventriculomegaly: report of 31 cases and review of literature. Ultrasound Obstet Gynecol. 1999;14:320–6

Aims and objectives We aim to investigate the antenatal course and subsequent neonatal outcome of isolated mild to moderate (10-15mm) ventriculomegaly (VM) at mid-trimester scan or subsequently in pregnancy. Material and methods We did a retrospective review of all cases of mild to moderate VM diagnosed at our hospital within the fetal medicine unit from 1 January 2006 to 31 May 2011. Data was collected from electronic databases from clinical notes. All mothers with initial diagnosis of isolated mild to moderate VM in the fetus had infection screen (toxoplasma, CMV and Parvo), invasive testing was offered based on serum screening results. MRI was offered if other CNS abnormalities were suspected or imaging was found to be inadequate. Observations Isolated mild to moderate VM was found in 33 (77%) fetuses at mid-trimester and in 10(23%) fetuses at subsequent scans. Two (4.5%) women had abnormal karyotype. None had abnormal infection screen. Isolated mild VM progressed to severe VM in 6 (14%) fetuses, was stable in 23 (53%) fetuses and resolved in 14 (33%) fetuses. There was one intrauterine fetal demise, 3 MTOP and 2NND. Three (8%) babies had other abnormalities. Two babies had global development delay. All other babies had normal neurological outcome. Conclusions In conclusion 2 (5%) of the livebirths had abnormal neurological outcome at 6 months- 5 year (Mean 20 months) follow up. Total perinatal loss including TOP was 7(18%). Thus truly normal outcome was seen in 29 (77%) fetuses with initial diagnosis of isolated mild to moderateVM.

Background Classically monozygotic (MZ) twins are considered identical. However, there are a number of cases of MZ twins concordant for genotype but not phenotype. A review of these cases was performed in our institution. Methods Patients who had monozygotic twin pregnancies with discordant anomalies but normal karyotype were identified from the Fetal Assessment Unit Database of the Rotunda Hospital between January 2006 and July 2011. A retrospective chart review was then performed. Results Fifteen pairs of monozygotic twins who were genotypically identical but phenotypically different were identified. Average maternal age was 28.6 years. 93% were spontaneously conceived and all had ultrasound assignment of chorionicity prior to 16 weeks gestation. Discordant anomalies detected by ultrasound included two cystic hygromas, one duodenal atresia, three spinal abnormalities, three cerebral abnormalities one Congenital Diaphragmatic Hernia, two Gastroschisis, one bilateral hydronephrosis, one single vessel cord and one twin with a two vessel cord. 73% confirmed normal karyotype with invasive testing. Two patients underwent laser ablation of connecting vessels and this was associated with intrauterine demise of the affected twin. Regarding outcomes of the other pregnancies, three had intrauterine death of both twins. The twin with CDH had an early neonatal death. Conclusion This is an interesting series which highlights the non-identical nature that can occur in monozygotic twin pregnancies. Emerging data shows that there are different types of genetic/epigenetic and prenatal post-zygotic mechanisms that can cause discordance within such twin pairs. This possibility should be included in counselling patients with monozygotic pregnancies.

We present a rare case of fetal α thalassaemia with hydrops fetalis born to a Filipino couple. Maternal Hb suggested α-thalassaemia trait. Given the high risk ethnic background for α0-thalassaemia the couple were tested for α-globin gene cluster which showed highly unstable alpha-chain variant Hb Adana leading to an α+thalassaemia phenotype. The risk for hydrops fetalis was 1 in 4. Amniocentesis showed normal karyotype. DNA analysis from amniocytes showed the fetus to be compound heterozygous for the α0–thalassaemia deletion and the Hb Adana mutation (genotype --FIL/ααAdana). The partners declined any interventions. Hydrops fetalis developed and intrauterine fetal death was diagnosed 28 weeks of gestation. National screening algorithm aims to identify couples at risk of Hb Barts hydrops fetalis due to homozygous α0-thalassaemia. Couples at risk for non deletional Hb H disease in England may not be identified by routine screening.

Background Eudicots are the most diverse group of flowering plants that compromise five well-defined lineages: core eudicots, Ranunculales, Proteales, Trochodendrales, and Buxales. However, the phylogenetic relationships between these five lineages and their chromosomal evolutions remain unclear, and a lack of high-quality genome analyses for Buxales has hindered many efforts to address this knowledge gap. Results Here, we present a high-quality chromosome-level genome of Buxus austro-yunnanensis (Buxales). Our phylogenomic analyses revealed that Buxales and Trochodendrales are genetically similar and classified as sisters. Additionally, both are sisters to the core eudicots, while Ranunculales was found to be the first lineage to diverge from these groups. Incomplete lineage sorting and hybridization were identified as the main contributors to phylogenetic discordance (34.33%) between the lineages. In fact, B. austro-yunnanensis underwent only one whole-genome duplication event, and collinear gene phylogeny analyses suggested that separate independent polyploidizations occurred in the five eudicot lineages. Using representative genomes from these five lineages, we reconstructed the ancestral eudicot karyotype (AEK) and generated a nearly gapless karyotype projection for each eudicot species. Within core eudicots, we recovered one common chromosome fusion event in asterids and malvids, respectively. Further, we also found that the previously reported fused AEKs in Aquilegia (Ranunculales) and Vitis (core eudicots) have different fusion positions, which indicates that these two species have different karyotype evolution histories. Conclusions Based on our phylogenomic and karyotype evolution analyses, we revealed the likely relationships and evolutionary histories of early eudicots. Ultimately, our study expands genomic resources for early-diverging eudicots.

Lancelets (‘amphioxus’) are the modern survivors of an ancient chordate lineage, with a fossil record dating back to the Cambrian period. Here we describe the structure and gene content of the highly polymorphic ∼520-megabase genome of the Florida lancelet Branchiostoma floridae , and analyse it in the context of chordate evolution. Whole-genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets and vertebrates), and allow not only reconstruction of the gene complement of the last common chordate ancestor but also partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution. The amphioxus genome: The key to the genetics of the last common chordate ancestor This issue sees the publication of the draft genome sequence of an animal that has been studied by biologists for many years as a model for a primitive chordate. The amphioxus or lancelet is a small worm-like creature, usually to be found buried in sand on the sea floor. Comparative analysis of the genome of the Florida lancelet, Branchiostoma floridae , reveals 17 ancestral chordate linkage groups conserved in the modern amphioxus and vertebrate genomes despite more than half a billion years of independent evolution. From this it possible to make a virtual reconstruction of the 17 chromosomes of the last common chordate ancestor. This reconstruction conforms that two rounds of whole genome duplication have occurred during evolution of the jawed vertebrate lineage. And it illuminates the murky relationships between the three chordate groups, the tunicates, lancelets and vertebrates. The cover shows four adult amphioxus collected in Apalachee Bay, Florida, with anterior towards the top and dorsal to the right. Yellow ovals are gonads. (Photo by Nicholas Putnam, DOE Joint Genome Institute.

Celery (Apium graveolens L. 2n = 2x = 22), a member of the Apiaceae family, is among the most important and globally grown vegetables. Here, we report a high-quality genome sequence assembly, anchored to 11 chromosomes, with total length of 3.33 Gb and N50 scaffold length of 289.78 Mb. Most (92.91%) of the genome is composed of repetitive sequences, with 62.12% of 31 326 annotated genes confined to the terminal 20% of chromosomes. Simultaneous bursts of shared long-terminal repeats (LTRs) in different Apiaceae plants suggest inter-specific exchanges. Two ancestral polyploidizations were inferred, one shared by Apiales taxa and the other confined to Apiaceae. We reconstructed 8 Apiales proto-chromosomes, inferring their evolutionary trajectories from the eudicot common ancestor to extant plants. Transcriptome sequencing in three tissues (roots, leaves and petioles), and varieties with different-coloured petioles, revealed 4 and 2 key genes in pathways regulating anthocyanin and coumarin biosynthesis, respectively. A remarkable paucity of NBS disease-resistant genes in celery (62) and other Apiales was explained by extensive loss and limited production of these genes during the last ~10 million years, raising questions about their biotic defence mechanisms and motivating research into effects of chemicals, for example coumarins, that give off distinctive odours. Celery genome sequencing and annotation facilitates further research into important gene functions and breeding, and comparative genomic analyses in Apiales.

Background Abnormal fetal tissue chromosome karyotypes are one of the important pathogenic factors for spontaneous abortion (SA). To analyze the characteristics of fetal tissue chromosomal karyotype in 778 women with a history of SA and its relationship with clinical features. Methods A retrospective study collected maternal age, body mass index (BMI), gestational weeks at miscarriage, the number of previous pregnancy losses and fetal tissue karyotypes CNV-seq data of 778 SA couples from Lanzhou University Second Hospital from October 2019 to December 2023, and described the characteristics of fetal tissue chromosomal karyotype and its relationship with clinical features. Results In our study, 432 patients (55.53% of total) had abnormal fetal tissue chromosomal karyotypes, with the highest incidence being trisomy syndrome (46.99%, 203/432). Advanced maternal age (> 35 years), early pregnancy (< 12 weeks), and a history of less than four previous pregnancy losses were all identified as risk factors for fetal tissue chromosomal abnormalities. Conclusion The results of this study indicate that fetal tissue chromosomal abnormalities are the primary factor leading to SA. Additionally, advanced maternal age (> 35years), early pregnancy (< 12 weeks), and the fewer number of previous pregnancy losses (≤ 4 times) are associated with a higher risk of fetal tissue chromosomal abnormalities following miscarriage.

Human beings are made of ~50 trillion cells which arise from serial mitotic divisions of a single cell - the fertilised egg. Remarkably, the early human embryo is often chromosomally abnormal, and many are mosaic, with the karyotype differing from one cell to another. Mosaicism presumably arises from chromosome segregation errors during the early mitotic divisions, although these events have never been visualised in living human embryos. Here, we establish live cell imaging of chromosome segregation using normally fertilised embryos from an egg-share-to-research programme, as well as embryos deselected during fertility treatment. We reveal that the first mitotic division has an extended prometaphase/metaphase and exhibits phenotypes that can cause nondisjunction. These included multipolar chromosome segregations and lagging chromosomes that lead to formation of micronuclei. Analysis of nuclear number and size provides evidence of equivalent phenotypes in 2-cell human embryos that gave rise to live births. Together this shows that errors in the first mitotic division can be tolerated in human embryos and uncovers cell biological events that contribute to preimplantation mosaicism. Human beings arise from serial mitotic divisions of a single fertilised egg. Here through live cell imaging of fertilized embryos the authors show that the first mitotic division is error prone and can contribute to preimplantation mosaicism.