Fetal de novo heterozygous variant in the isocitrate dehydrogenase 1 gene associated with growth restriction,skeletal, cerebral and vascular anomalies

Germline pathogenic variants in isocitrate dehydrogenase 1 (IDH1) can lead to a rare neurodevelopmental disorder called metaphyseal chondromatosis with D-2-hydroxyglutaric aciduria, including severe skeletal and cerebral anomalies. To the best of our knowledge, no prenatal case of an IDH1 pathogenic variant has been reported in literature. Somatic sequence variants in IDH1/2 genes are described in distinct cancers, premalignant diseases and rare inherited metabolic disorders. Amniocentesis and further genetic testing including trio exome sequencing were performed due to suspicious findings on a second trimester routine prenatal ultrasound examination. The fetus was found to have growth restriction, cerebral abnormalities (ex vacuo hydrocephalus, cerebellar and vermian hypoplasia, corpus callosum dysgenesis), brachycephaly, narrow chest, persistent left superior vena cava, liver calcifications, hyperechogenic bowel, short tubular bones and joint contractures. A de novo heterozygous variant in the IDH1 gene was detected via trio exome sequencing. The prenatal diagnosis of a de novo pathogenic variant in IDH1 in a fetus with the described phenotype, obtained through trio exome sequencing, helped parents and providers with an informed decision making about pregnancy management.     

A homolog of the hydrolase Notum is expressed during segmentation and appendage formation in the Central American hunting spider Cupiennius salei

The hydrolase Notum (also known as Wingful) has been implicated in shaping the distribution gradient of the morphogen Wingless in Drosophila by modifying the Wingless-binding heparan sulfate proteoglycan (HSPG) core glypicans Dally and Dally-like. Here we report on the expression of a Notum homolog during the embryonic development of the spider Cupiennius salei. Notum is expressed in two to three stripes in the posterior region of the germband where new segments are formed. At this location no Wingless expression is present, suggesting that Notum may be involved in the regulation of another HSPG-binding morphogen, possibly Hedgehog. In older segments, however, expression of Notum and Wingless roughly coincides. In the appendages, Notum is expressed in ventral mesodermal cells, directly adjacent to the Wingless expressing ectodermal cells. This could indicate a role for the mesoderm in regulating morphogen gradient formation in the ectoderm.     

Prenatal diagnosis for arginase deficiency by second-trimester fetal erythrocyte arginase assay and first-trimester ARG1 mutation analysis

Hyperargininemia is a progressive neurometabolic disorder caused by deficiency of hepatic cytosolic arginase I, resulting from mutations in the ARG1 gene. We diagnosed arginase deficiency in a three-year-old male child of first-cousin Palestinian Arab parents. Prenatal diagnosis of an unaffected fetus was achieved in the second trimester of a subsequent pregnancy by cordocentesis and analysis of arginase activity in fetal erythrocytes. ARG1 mutation analysis in the proband revealed homozygosity for a deletion of 10 753 bp extending from the first intron to beyond the poly (A) site of the gene. This is the first gross deletion in the ARG1 gene to be identified and the first mutation to be described in an arginase-deficient patient of this ethnic origin. The identification of the ARG1 deletion in this family enabled first-trimester prenatal diagnosis in a subsequent pregnancy by multiplex PCR analysis performed on chorionic villous DNA. Copyright © 2004 John Wiley & Sons, Ltd.     

Aversive odorant causing appetite decrease downregulates tyrosine decarboxylase gene expression in the olfactory receptor neuron of the blowfly, Phormia regina

In the blowfly Phormia regina, exposure to d-limonene for 5 days during feeding inhibits proboscis extension reflex behavior due to decreasing tyramine (TA) titer in the brain. TA is synthesized by tyrosine decarboxylase (Tdc) and catalyzed into octopamine (OA) by TA ?-hydroxylase (Tbh). To address the mechanisms of TA titer regulation in the blowfly, we cloned Tdc and Tbh cDNAs from P. regina (PregTdc and PregTbh). The deduced amino acid sequences of both proteins showed high identity to those of the corresponding proteins from Drosophila melanogaster at the amino acid level. PregTdc was expressed in the antenna, labellum, and tarsus whereas PregTbh was expressed in the head, indicating that TA is mainly synthesized in the sensory organs whereas OA is primarily synthesized in the brain. d-Limonene exposure significantly decreased PregTdc expression in the antenna but not in the labellum and the tarsus, indicating that PregTdc expressed in the antenna is responsible for decreasing TA titer. PregTdc-like immunoreactive material was localized in the thin-walled sensillum. In contrast, the OA/TA receptor (PregOAR/TAR) was localized to the thick-walled sensillum. The results indicated that d-limonene inhibits PregTdc expression in the olfactory receptor neurons in the thin-walled sensilla, likely resulting in reduced TA levels in the receptor neurons in the antenna. TA may be transferred from the receptor neuron to the specific synaptic junction in the antennal lobe of the brain through the projection neurons and play a role in conveying the aversive odorant information to the projection and local neurons.     

妊娠期全氟辛酸染毒对子代雄鼠发育毒性的研究

探讨妊娠期染毒全氟辛酸(perfluorooctanoic acid,PFOA)对子代雄鼠发育毒性的影响.将50只妊娠0 d小鼠随机分5组,每组10只,妊娠0~17 d每天按0、1、2.5、5和12.5 mg·kg~(-1)BW饲喂PFOA,产后仔鼠正常饲养,记录仔鼠存活数.产后21 d,检测仔鼠血清睾酮水平并计算睾丸指数;HE染色观察睾丸组织结构变化;RT-PCR法检测睾丸组织Dlk1-Dio3印记基因簇各目的基因mRNA的表达情况.结果显示,随PFOA染毒剂量增加,仔鼠存活数显著降低,血清睾酮含量极显著性降低(p0.01);睾丸指数无统计学意义;睾丸组织有不同程度的损伤并呈剂量依赖性;Dlk1-Dio3印记基因簇各目的基因的表达量都有降低趋势,其中Gtl2、Rian、Dio3均显著性降低(p0.05).结果表明,妊娠期染毒PFOA能够降低仔鼠存活数,损伤睾丸组织结构,并能够扰乱生殖激素,降低睾丸组织Dlk1-Dio3印记基因簇各目的基因mRNA的表达.     

Prenatal diagnosis of a lethal form of Netherton syndrome by SPINK5 mutation analysis

Netherton syndrome (NS) is a severe autosomal recessive ichthyosis with no specific treatment or prenatal diagnosis available at present. The recent identification of SPINK5, which encodes a serine protease inhibitor, as the defective gene enables DNA-based prenatal diagnosis to be carried out. Here we report the first direct molecular prenatal diagnosis of a lethal form due to a recurrent SPINK5 mutation in three consanguineous Turkish families. XmnI restriction enzyme digestion and DNA sequencing demonstrated that each deceased affected child was homozygous for mutation 153delT inherited from each parent. Analysis of fetal DNA from amniotic fluid cells in Family 1 and from a chorionic villus sampling in Family 3 showed that the fetus was heterozygous for 153delT in both cases. The pregnancies were carried to term and the newborns were unaffected. In Family 2, fetal DNA analysis from chorionic villus biopsy showed in a first pregnancy that the fetus was homozygous for 153delT. The pregnancy was terminated at 13 weeks and DNA analysis of fetal keratinocytes confirmed the prenatal prediction. In a second pregnancy in Family 2, fetal DNA analysis showed heterozygosity for 153delT, and the pregnancy was continued. Direct SPINK5 mutation analysis in families at risk for NS represents the first early, rapid and reliable method for prenatal diagnosis of this life-threatening form of ichthyosis. Copyright © 2002 John Wiley & Sons, Ltd.     

Prenatal overgrowth and mosaic trisomy 15q25-qter including the IGF1 receptor gene

Overgrowth is rarely associated with chromosomal imbalances. Here, we report on a male foetus presenting with overgrowth and additional material on the short arm of one of the chromosome 15 in 12% of lymphocytes and 50% of amniotic cells. Parents' karyotypes were normal, indicating a de novo origin for this unbalanced rearrangement. Complementary studies using cytogenetic and FISH studies showed that this additional material resulted in a 15q25-qter trisomy and confirmed the presence of three copies of the insulin-like growth factor 1 receptor (IGF1R) gene, included in the trisomic region. Autopsy performed after termination of pregnancy revealed isolated overgrowth and absence of visceral malformations. The possible mechanisms and origins for the formation of this mosaic pure trisomy are complex. The present observation emphasises the hypothesis that the overgrowth phenotype, frequently reported in patients with trisomy including the 15q26 region, might be causally related to a dosage effect of the IGF1R gene, as well as the importance of chromosome analysis in patients with overgrowth. It also confirms that the overgrowth is of prenatal onset in those observations. Copyright © 2004 John Wiley & Sons, Ltd.     

SMARCC1 is a susceptibility gene for congenital hydrocephalus with an autosomal dominant inheritance mode and incomplete penetrance

A Jewish couple of mixed origin was referred for genetic counseling following termination of pregnancy at 18 weeks of gestation due to severe ventriculomegaly with aqueduct stenosis. Trio exome sequencing revealed a loss-of-function heterozygous variant in the SMARCC1 gene inherited from an unaffected mother. The SMARCC1 gene is associated with embryonic neurodevelopmental processes. Recent studies have linked perturbations of the gene with autosomal dominant congenital hydrocephalus, albeit with reduced penetrance. However, these studies were not referenced in the SMARCC1 OMIM record (*601732) and the gene was not considered, at the time, an OMIM morbid gene. Following our case and appeal, SMARCC1 is now considered a susceptibility gene for hydrocephalus. This allowed us to reclassify the variant as likely pathogenic and empowered the couple to make informed reproductive choices.     

Between pregnancy biological variability of first trimester markers of Down syndrome: implications for screening in subsequent pregnancies

In a group of 149 women who had undergone routine first trimester screening using fetal nuchal translucency thickness (NT) and maternal serum free β-hCG and pregnancy associated plasma protein-A (PAPP-A) in two consecutive pregnancies the within person between pregnancy biological variability of these markers has been assessed. For fetal NT there was no correlation between NT MoM in the first and second pregnancy (r=0.0800). For maternal serum free β-hCG MoM a significant correlation was observed (r=0.4174) as was also found for PAPP-A MoM (r=0.3270). The implications for such between pregnancy marker association is that women who have an increased risk of Down syndrome in their first pregnancy are 1.5–2 times more likely to repeat this event in their next pregnancy. This observation may be useful in counselling women in the first trimester screening of a subsequent pregnancy. Copyright © 2001 John Wiley & Sons, Ltd.     

Cytogenetic analysis of trophoblasts by comparative genomic hybridization in embryo-fetal development anomalies

Cytogenetic studies of spontaneous abortions or intrauterine fetal death depend on conventional tissue culturing and karyotyping. This technique has limitations such as culture failure and selective growth of maternal cells. Fluorescent in situ hybridization (FISH) using specific probes permits diagnosis of aneuploidies but is limited to one or a few chromosomal regions. Comparative genomic hybridization (CGH) provides an overview of chromosomal gains and losses in a single hybridization directly from DNA samples. In a prospective study, we analyzed by CGH trophoblast cells from 21 fetuses in cases of spontaneous abortions, intrauterine fetal death or polymalformed syndrome. Six numerical chromosomal abnormalities including one trisomy 7, one trisomy 10, three trisomies 18, one trisomy 21 and one monosomy X have been correctly identified by CGH. One structural abnormality of the long arm of chromosome 1 has been characterized by CGH. One triploidy and two balanced pericentromeric inversions of chromosome 9 have not been identified by CGH. Sexual chromosomal constitutions were concordant by both classical cytogenetic technique and CGH. Contribution of trophoblast analysis by CGH in embryo-fetal development anomalies is discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Ubiquity of parasporin-1 producers in <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> natural populations of Japan

Parasporin, a Bacillus thuringiensis parasporal protein, is unique in having a strong cytocidal activity preferential for human cancer cells. In this study, we characterized parasporin activities associated with three novel geographical isolates of B. thuringiensis. Parasporal inclusion proteins of the three isolates were highly toxic to human uterus cervix cancer cells (HeLa), but not to non-cancer uterine smooth muscle cells (UtSMC). Inclusions of the isolates lacked insect toxicity and hemolytic activity against sheep erythrocytes. Ouchterlony immunodiffusion tests revealed that the proteins of the three isolates are immunologically closely related to parasporin-1 (Cry31A), but dissimilar to the three other existing parasporin groups. Our results provide evidence that the parasporin-1-producing organism is a common member in B. thuringiensis populations occurring in natural environments of Japan.     

二氧化硫胁迫下拟南芥miRNA表达谱分析

以拟南芥为材料,利用高通量测序技术并结合生物信息学分析方法,检测二氧化硫(SO_2)处理后拟南芥植株的小分子RNA表达谱,筛选SO_2胁迫响应microRNAs(miRNAs)分子,研究植物miRNAs对逆境胁迫的应答机制.结果发现,30 mg·m~(-3) SO_2处理72 h后,拟南芥地上组织小分子RNA长度分布发生改变,在对照组和SO_2组中均有大量特有的小分子RNA序列,说明SO_2胁迫可诱导拟南芥小分子RNA的表达改变.SO_2胁迫诱导186个保守miRNA和16个新miRNA分子差异表达,其靶基因主要涉及转录调控、信号转导、代谢、刺激响应等生理过程.差异表达的miR160和miR393可通过生长素信号途径调控植株生长发育,参与植物对SO_2的胁迫响应.本研究揭示了植物中参与SO_2胁迫应答的miRNA种类及作用机制,进一步阐明了miRNAs在植物抗逆应答过程中的作用.     

Correlation between phenotypic expression of de novo marker chromosomes and genomic organization using replicational banding

It has been suggested that actively expressed genes are primarily located in early replicating bands. This hypothesis is supported by cytogenetic and pregnancy outcome data from four consecutive cases of prenatally detected de novo marker chromosomes. Two fetuses with major anomalies had large early replicating bands, while the marker in a third phenotypically normal fetus was late replicating. In the fourth case, a ring marker chromosome had only a small early replicating region. Pregnancy termination was elected. While no structural malformations were apparent, potential intellectual function in this case remains unresolved. An understanding of the relationship between genomic organization and chromosome banding is critical in counseling for prenatally detected de novo marker chromosomes. Replicational banding is particularly helpful in recognizing genes that may be actively expressed and result in developmental abnormality.     

2,3,7,8,-四氯苯噁英对NIH小鼠早期妊娠和生殖激素的影响

用不同剂量的2,3,7,8 四氯苯二英(2,3,7,8 tetrachlorodibenzopdioxin,TCDD)对小鼠胚胎附植数量和生长发育情况进行剂量反应评估,分析TCDD对假孕小鼠子宫蜕膜生长状况的影响以及比较胚胎种植前后染毒效果.所有样本采集血液,测定母体血清雌二醇和孕酮的浓度变化.结果表明,50和100ng·(kg·d)-1TCDD处理的孕鼠,胚胎附植数量明显减少(P<0 05),着床后胚胎出现发育迟缓,质量减轻(P<0 05);同等剂量TCDD处理的假孕小鼠,子宫蜕膜生长受到了极显著的抑制(P<0 01);种植前后染毒效果比较发现种植前期染毒的小鼠胚胎对TCDD更为敏感.母体血清雌二醇浓度随剂量和染毒时段有不同程度的升高,而孕酮浓度则极显著下降(P<0 01).由此表明低剂量TCDD可能通过对生殖激素的干扰,强烈影响NIH小鼠妊娠早期生殖生理状态和着床后胚胎的发育.实验同时证明小鼠也可作为早期妊娠毒物研究的供试动物,用以筛选动物和人类早期妊娠的有害化合物.     

Fetal diagnosis of toxoplasmosis in 190 women infected during pregnancy

One hundred and ninety women who contracted toxoplasmosis after the seventh week of pregnancy underwent antenatal diagnosis, including ultrasound examination and biological tests. Tests included Toxoplasma isolation in fetal blood and amniotic fluid by mouse inoculation, specific IgM and IgA in fetal blood, and non-specific tests. Twenty fetuses had positive specific as well as non-specific tests for Toxoplasma infection. At birth, four of these presented with clinical congenital toxoplasmosis and 12 with subclinical forms. Antenatal diagnosis enabled the detection of 83 per cent of the infected fetuses. Under specific conditions, cordocentesis permits early diagnosis and considerably reduces the number of terminations of pregnancy.     

Comparative study of 15 lysosomal enzymes in chorionic villi and cultured amniotic fluid cells. Early prenatal diagnosis in seven pregnancies at risk for lysosomal storage diseases

A large number of chorionic villi samples obtained from women undergoing elective first trimester termination of pregnancy was analysed by enzyme assays similar to those applied to cultured amniotic cells. The levels of 15 lysosomal enzymes were compared to those observed in tissue cultures of amniotic cells obtained through amniocentesis at 16-18 weeks of pregnancy and the results were discussed in order to assess the usefulness of trophoblast biopsy for first trimester diagnosis of hereditary lysosomal diseases. The data suggest the applicability of this source of fetal cells for prenatal diagnosis of fifteen respective genetically determined enzyme deficiencies with the probable exception of α-L -iduronidase deficiency. Enzyme determinations were performed on chorionic villi samples of two pregnancies at risk for Tay-Sachs disease, three pregnancies for GM₁ gangliosidosis type 1, one for mucopolysaccharidosis type VI and one for Wolman's disease.     

Differentiation in human chorionic villus cultures: hCG and hla expression

The present report describes methods to separate, culture, and study syncytio-cytotrophoblast and mesenchymal core of the first-trimester human chorionic villus. The cultured outer layer cells (syncytio-cytotrophoblast) are multinucleated, pleomorphic, and active in the formation of human chorionic gonadotrophin (hCG). The mesenchymal core cells are more fibroblast-like in appearance, do not show multinucleation, and have less hCG in their culture media. Both cultured cell types express HLA (ABC) Class I histocompatibility antigens but not HLA (DR) Class II antigens. These and previous studies from this laboratory postulate different embryonic origins: (1) Syncytio-cytotrophoblast cultures of chorionic villus derive from differentiated trophoblast and preserve multinucleation as well as hCG hormone function. (2) Cells cultured from the chorionic villus core originate from extraembryonic mesenchyme. (3) Amniocytes (AF cells) cultured from amniotic fluid resemble the multipotential and early-stage trophoblast, retaining pleomorphism, multinucleation, and lacunae formation as well as production of hCG, progesterone, oestrogen, basement membrane glycoprotein, and Type IV collagen. These cell types cultured from the chorionic villus and amniotic fluid provide a means for in vitro study of specific embryonic cell lineages.     

Duplex PCR for preimplantation genetic diagnosis (PGD) of spinal muscular atrophy

The main difficulty in developing a molecular diagnosis of spinal muscular atrophy (SMA) resides in the specific genomic structure of the locus. Indeed, two highly homologous survival motor neurone genes, SMN1 and SMN2, are present at the locus. The detection of the homozygous deletion of exons 7 and 8 of the SMN1 gene, which is present in 90 to 98% of the patients, is based on methods highlighting 1 of the 8 nucleotidic mismatches existing between these 2 genes. In order to offer preimplantation genetic diagnosis (PGD) for SMA, we developed a new allele-specific amplification method. The main disadvantage of our previously described strategy resided in the possibility of diagnosing, in case of amplification failure, an unaffected embryo as affected. We present here a new PGD-SMA method. We established the conditions for three different duplex PCRs, allowing the specific detection of the SMN1 gene and one polymorphic marker, either D5S629, D5S1977, or D5S641. Of the 60 to 90 single cells tested, the PCR efficiency varied from 98 to 100% with a complete genotype obtained in a range between 81 and 87% with a global allele drop-out rate of 9%. Such a test was used to perform 1 PGD cycle for which 7 embryos could be analysed. All the embryos were fully diagnosed, six as unaffected and one as affected. Four embryos were transferred, but no pregnancy ensued. Copyright © 2003 John Wiley & Sons, Ltd.     

Undiagnosed heterotopic pregnancy,maternal hemorrhagic shock,and ischemic stroke in the intrauterine fetus

Heterotopic pregnancy occurs rarely following natural conception; however, intrauterine embryo transfer following in vitro fertilization is a known risk factor for its occurrence. A 29-year-old woman presented with acute abdomen at 14w5d gestation following in vitro fertilization–embryo treatment. A ruptured heterotopic gestation in the left fallopian tube was identified at laparoscopy and treated by salpingectomy. Subsequently, at 21-week gestation, routine sonogram demonstrated bilateral ventriculomegaly in the intrauterine fetus. Fetal magnetic resonance imaging was highly suggestive of ischemic brain injury, most likely attributable to the maternal hypovolemic shock because of ruptured heterotopic gestation. The pregnancy was terminated by intracardiac injection and induction of labor. Timely diagnosis of heterotopic pregnancy requires a high index of suspicion as diagnostic delays can have catastrophic consequences for the mother and/or the intrauterine fetus. © 2015 John Wiley & Sons, Ltd.