Syncytiotrophoblast Markers Are Downregulated in Placentas from Idiopathic Stillbirths

The trophoblast cells are responsible for the transfer of nutrients between the mother and the foetus and play a major role in placental endocrine function by producing and releasing large amounts of hormones and growth factors. Syncytiotrophoblast cells (STB), formed by the fusion of mononuclear cytotrophoblasts (CTB), constitute the interface between the foetus and the mother and are essential for all of these functions. We performed transcriptome analysis of human placental samples from two control groups-live births (LB), and stillbirths (SB) with a clinically recognised cause-and from our study group, idiopathic stillbirths (iSB). We identified 1172 DEGs in iSB, when comparing with the LB group; however, when we compared iSB with the SB group, only 15 and 12 genes were down- and upregulated in iSB, respectively. An assessment of these DEGs identified 15 commonly downregulated genes in iSB. Among these, several syncytiotrophoblast markers, like genes from the PSG and CSH families, as well as ALPP, KISS1, and CRH, were significantly downregulated in placental samples from iSB. The transcriptome analysis revealed underlying differences at a molecular level involving the syncytiotrophoblast. This suggests that defects in the syncytial layer may underlie unexplained stillbirths, therefore offering insights to improve clinical obstetrics practice.

Impact of copy number variants in epilepsy plus neurodevelopment disorders

INTRODUCTION

Epilepsy, a neurological disorder characterized by recurring unprovoked seizures due to excessive neuronal excitability, is primarily attributed to genetic factors, accounting for an estimated 70 % of cases. Array-comparative genomic hybridization (aCGH) is a crucial genetic test for detecting copy number variants (CNVs) associated with epilepsy. This study aimed to analyze a cohort of epilepsy patients with CNVs detected through aCGH to enhance our understanding of the genetic underpinnings of epilepsy.

METHODS

A retrospective cross-sectional study was conducted using the aCGH database from the Genetics Department of the Faculty of Medicine of the University of Porto, encompassing 146 patients diagnosed with epilepsy, epileptic encephalopathy, or seizures. Clinical data were collected, and aCGH was performed following established guidelines. CNVs were classified based on ACMG standards, and patients were categorized into four groups according to their clinical phenotype.

RESULTS

Among the 146 included patients, 94 (64 %) had at least one CNV, with 22 (15.1 %) classified as pathogenic or likely pathogenic. Chromosomes 1, 2, 16, and X were frequently implicated, with Xp22.33 being the most reported region (8 CNVs). The phenotype "Epilepsy and global developmental delay/intellectual disability" showed the highest prevalence of clinically relevant CNVs. Various CNVs were identified across different groups, suggesting potential roles in epilepsy.

CONCLUSIONS

This study highlights the significance of aCGH in unraveling the genetic basis of epilepsy and tailoring treatment strategies. It contributes valuable insights to the expanding knowledge in the field, emphasizing the need for research to elucidate the diverse genetic causes of epilepsy.

Kidney failure secondary to hereditary xanthinuria due to a homozygous deletion of the XDH gene, in the absence of overt kidney stone disease

Hereditary xanthinuria (HXAN) is a rare metabolic disorder that results from mutations in either the xanthine dehydrogenase (XDH) or the molybdenum cofactor sulfurase genes (MOCOS), respectively defining HXAN type I and type II. Hypouricemia, hypouricosuria, and abnormally high plasma and urine levels of xanthine, causing susceptibility to xanthine nephrolithiasis and deposition of xanthine crystals in tissues, are the metabolic hallmarks of HXAN. Several pathogenic variants in the XDH gene have so far been identified in patients with HXAN type I, but the clinical phenotype associated with the whole deletion of the human XDH gene is unknown. Herein, we report the case of a woman diagnosed with HXAN, whose molecular genetic testing revealed a homozygous microdeletion involving the XDH gene. Distinctive features of her medical history were the diagnosis of arterial hypertension and microalbuminuria at 22 years of age; a single pregnancy, at the age of 25, complicated by proteinuria and transient kidney function deterioration in the third trimester; unexplained severe hypouricaemia incidentally discovered during pregnancy; inability to breastfeed her newborn daughter due to primary agalactia; chronic kidney disease (CKD) stage 3 diagnosed at age 35; and progression to end-stage kidney disease over the next 12 years. Protocol non-invasive laboratory and imaging investigation was not informative as to the cause of CKD. This is the first description of the clinical phenotype associated with a natural knockout of the human XDH gene. Despite the lack of kidney histopathology data, the striking similarities with the phenotypes exhibited by comparable murine models validates the latter as useful sources of mechanistic insights for the pathogenesis of the human disease, supporting the hypothesis that the absence of xanthine dehydrogenase activity might represent a susceptibility factor for chronic tubulointerstitial nephritis, even in patients without kidney stones.

Balanced chromosomal rearrangements implicate YIPF5 and SPATC1L in non-obstructive oligoasthenozoospermia and oligozoospermia and of a derivative chromosome 22 in recurrent miscarriage

Naturally occurring balanced, unbalanced, and complex chromosomal rearrangements have been reported to cause pathogenic genomic or genetic variants leading to infertility and recurrent miscarriage. Therefore, balanced chromosomal rearrangements were used as genomic signposts for identification of candidate genes or genomic loci associated with male infertility due to defects of spermatogenesis, or with recurrent miscarriage. In three male probands, structural chromosomal variants and copy number variants were identified at nucleotide resolution by long-insert genome sequencing approaches and Sanger sequencing. The pathogenic potential of these and affected candidate genes was assessed based on convergent genomic and genotype-phenotype correlation data. Identification of balanced chromosomal rearrangement breakpoints and interpretation in the context of their genomic background of structural and copy number variants led us to conclude that the infertility due to oligoasthenozoospermia and oligozoospermia is most likely associated with a position effect on YIPF5 and SPATC1L, respectively. In a third proband with intellectual disability and recurrent miscarriage, disruption of CAMK2B causing autosomal dominant, intellectual developmental disorder 54 and increased meiotic segregation during gametogenesis of a der(22) are responsible for the reported phenotype. Our data further support the existence of loci at 5q23 and 21q22.3 for these spermatogenesis defects and highlight the importance of the naturally occurring balanced chromosomal rearrangements for assessment of the pathogenic mechanisms. Furthermore, we show comorbidities due to the same balanced chromosomal rearrangement caused by different pathogenic mechanisms.

Severe KIDAR syndrome caused by deletion in the AP1B1 gene: Report of a teenage patient and systematic review of the literature

Autosomal recessive keratitis-ichthyosis-deafness syndrome (KIDAR MIM #242150) is a very rare disorder caused by pathogenic loss-of-function variants in the AP1B1 gene. So far, nine patients have been reported in the literature and more clinical descriptions are essential to further delineate the phenotype of KIDAR. Here we report a new patient with KIDAR and compare the clinical findings with those from the other published cases with molecular confirmation. We describe a 14-year-old male born to non-consanguineous parents with unremarkable family history. The patient had fetal ascites, neonatal pancreatic insufficiency with consequent failure to thrive, feeding difficulties, recurrent infections and sepsis. The skin examination was remarkable for an ichthyosis with conspicuous palmoplantar keratoderma, sparse and brittle hair with alopecia on the vertex and slight bilateral ectropion. He had short stature, thin build, frontal bossing, small teeth and prominent abdomen. Additional features were congenital profound bilateral sensorineural deafness, photosensitivity and photophobia. Mild global developmental delay was noted. Persistent mild anemia, neutropenia, thrombocytopenia, and low serum copper, ceruloplasmin and growth hormone were also present. Brain magnetic resonance imaging (MRI) showed cerebral atrophy and thin corpus callosum. Genetic testing revealed a homozygous deletion in the AP1B1 gene, possibly including the same exons as a previously reported deletion. Comparing the phenotypes of all reported individuals, they are highly concordant and major features are enteropathy with feeding difficulties, failure to thrive, ichthyosis, palmoplantar keratoderma, sensorineural deafness and sparse and brittle hair. Here we report other features present in more than one patient that could be part of the phenotypic spectrum and suggest copy number variation analysis to be performed alongside sequencing of the AP1B1 gene in case of suspicion.

The role of DNA hydroxymethylation and TET enzymes in placental development and pregnancy outcome

The placenta is a temporary organ that is essential for supporting mammalian embryo and fetal development. Understanding the molecular mechanisms underlying trophoblast differentiation and placental function may contribute to improving the diagnosis and treatment of obstetric complications. Epigenetics plays a significant role in the regulation of gene expression, particularly at imprinted genes, which are fundamental in the control of placental development. The Ten-Eleven-Translocation enzymes are part of the epigenetic machinery, converting 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). DNA hydroxymethylation is thought to act as an intermediate in the DNA demethylation mechanism and potentially be a stable and functionally relevant epigenetic mark on its own. The role of DNA hydroxymethylation during differentiation and development of the placenta is not fully understood but increasing knowledge in this field will help to evaluate its potential role in pregnancy complications. This review focuses on DNA hydroxymethylation and its epigenetic regulators in human and mouse placental development and function. Additionally, we address 5hmC in the context of genomic imprinting mechanism and in pregnancy complications, such as intrauterine growth restriction, preeclampsia and pregnancy loss. The cumulative findings show that DNA hydroxymethylation might be important for the control of gene expression in the placenta and suggest a dynamic role in the differentiation of trophoblast cell types during gestation.

Klinefelter syndrome: The characterization of the clinical and sociological features of 51 patients

INTRODUCTION

Klinefelter syndrome is the most frequently found aneuploidy among male patients. Its clinical presentation is very heterogeneous, and thus poses a challenge for a timely diagnosis.

METHODS

A retrospective study was carried out with 51 consecutively selected patients diagnosed with Klinefelter Syndrome from Jan/2010 to Dec/2019. The karyotypes were identified using high resolution GTL banding at the Genetics Department. Multiple clinical and sociological parameters were studied by collecting data from the clinical records.

RESULTS

44 (86%) of the 51 patients presented a classical karyotype (47,XXY) and 7 (14%) showed evidence of mosaicism. The mean age at diagnosis was 30.2±14.3 years old. Regarding the level of education (N=44), 26 patients (59.1%) had no secondary education, with 5 (11.4%) patients having concluded university studies. Almost two thirds of the sample revealed learning difficulties (25/38) and some degree of intellectual disability was present in 13.6% (6/44). Half of the patients were either non-qualified workers (19.6%) or workers in industry, construction, and trades (30.4%), which are jobs that characteristically require a low level of education. The proportion of unemployed patients was 6.5%. The main complaints were infertility (54.2%), followed by hypogonadism-related issues (18.7%) and gynecomastia (8.3%). 10 patients (23.8%, N=42) were biological parents. With regards the question of fertility, assisted reproductive techniques were used in 39.6% of the studied subjects (N=48), with a success rate (a take home baby) of 57.9% (11/19), 2 with donor sperm and 9 with the patients' own gametes. Only 41% of the patients (17/41) were treated with testosterone.

CONCLUSION

This study identifies the most important clinical and sociological findings of Klinefelter syndrome patients that should be considered when deciding workout and disease management.

Clinical Findings on Chromosome 1 Copy Number Variations

Copy number variants (CNVs) are a major contribution to genome variability, and the presence of CNVs on chromosome 1 is a known cause of morbidity. The main objective of this study was to contribute to chromosome 1 disease map, through the analysis of patients with chromosome 1 CNVs.A cross-sectional study was performed using the array comparative genomic hybridization database of the Genetic Department of the Faculty of Medicine. Patients with pathogenic (P) or likely pathogenic (LP) CNVs on chromosome 1 were selected for the study. Clinical information was collected for all patients. Databases and related literature were used for genotype-phenotype correlation.From a total of 2,516 patients included in the database we identified 24 patients (0.95%) with P (9 patients) or LP (15 patients) CNVs on chromosome 1. These CNVs account for 6.1% (24/392 CNVs) of the total P/LP CNVs in the database. Most common CNVs found were in the 1q21.1-1q21.2 region.This study reinforces the association between chromosome 1 CNV and neurodevelopmental disorders and craniofacial dysmorphisms. Additionally, it also strengthened the idea that CNVs interpretation is not always a linear task due to the broad spectrum of variants that can be identified between benign and clearly pathogenic CNVs.

Clinical outcomes of 77 TESE treatment cycles in non-mosaic Klinefelter syndrome patients

OBJECTIVE

The current study aimed to present the clinical outcomes of 76 azoospermic patients with non-mosaic Klinefelter syndrome (KS), treated with testicular spermatozoa extraction (TESE) followed by intracytoplasmic sperm injection (ICSI) using either fresh or cryopreserved testicular spermatozoa.

METHODS

We retrospectively evaluated 76 patients with non-mosaic KS belonging to a special group of cases that besides infertility did not present the classical signs and symptoms of testosterone deficiency. One of the patients repeated the TESE procedure (76 patients, 77 TESE cycles). Sixty of these 76 patients accepted to undergo TESE associated with ovarian stimulation, while 16 patients underwent TESE followed by testicular spermatozoa cryopreservation. Aneuploidy screening of the offspring was performed by Multiplex ligation-dependent probe amplification and by amniotic fluid karyotyping. Statistical analysis used the Chi-Squared Test, Fisher's Exact Test, 2-sided, for rates, and the Independent Samples T-test for equality of means, 2-sided.

RESULTS

Testicular spermatozoa were recovered in 31 (40.3%) of the attempts. The patients underwent 47 ICSI cycles, 25 with fresh testicular spermatozoa and 22 with cryopreserved testicular spermatozoa. Fertilization (63.5% vs. 41.6%, p=0.000), implantation (37% vs. 13.2%, p=0.014), clinical pregnancy (60.9% vs. 19%, p=0.005) and live birth (65.2% vs. 23.8%, p=0.006) rates were higher with fresh testicular spermatozoa. Chromosome analysis of the 21 newborns was normal.

CONCLUSIONS

The present data adds further information regarding the recovery rate of spermatozoa after TESE and the embryological and clinical outcomes with fresh and cryopreserved testicular spermatozoa, besides reassuring the safety concerning chromosomal transmission of KS from parents to their offspring.

P–038 Clinical outcomes of 77 testicular sperm extraction treatment cycles in non-mosaic Klinefelter syndrome patients

Study question

What are the clinical results of patients with azoospermia and nonmosaic Klinefelter syndrome, using fresh and cryopreserved sperm?

Summary answer

The results showed a recovery rate of testicular sperm in the order of 40% and a life newborn rate of 52% when using fresh sperm

What is known already

In Klinefelter syndrome (KS), the rates of successful testicular sperm retrieval were shown to be similar either using conventional TESE or micro-TESE (Corona et al., 2017), which highlights that the variability observed between studies is due to differences in patient characteristics. There are a few works with a large number of KS patients elucidating the clinical outcomes using fresh and cryopreserved testicular sperm. However, these studies revealed contradictory outcomes, either revealing better (Greco et al., 2013; Vicdan et al., 2016) or worst (Madureira et al., 2014) results with cryopreserved testicular sperm, or finding no differences (Chen et al, 2019).

Study design, size, duration

This study includes all patients up to 2019 presenting azoospermia due to non-mosaic Klinefelter syndrome (n = 76) that went for infertility consultations in a private fertility clinic. Patients were evaluated by the same Urologist. The genetic analysis of the patients was performed at an academic institution. At examination patients did not refer other complaints besides infertility, and referred to have not received any hormone replacement therapy in the past.

Participants/materials, setting, methods

The 76 azoospermic patients with non-mosaic Klinefelter syndrome (KS) were treated by testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection (ICSI), using fresh and cryopreserved testicular sperm. Most patients used fresh testicular sperm, where others preferred to postpone ICSI treatment cycles and used cryopreserved testicular sperm. Aneuploidy screening in children was performed by prenatal diagnosis and MLPA (Multiplex ligation-dependent probe amplification). Full embryological, clinical and newborn outcomes are provided.

Main results and the role of chance

Of the 76 patients with non-mosaic Klinefelter syndrome, one repeated the testicular sperm extraction (TESE) procedure. Testicular sperm were recovered in 31/77 (40.3%) of the cases. Comparisons between the 31 cases with successful sperm recover (group–1) and the 46 cases without a successful TESE (group–2) revealed no significant differences regarding age, time of infertility, testicular volume, serum levels of FSH, LH and testosterone, total number of testicular fragments analyzed, and time of search in samples. The mean male age was 34 years. In most of the cases, the testicular volume was reduced (96.1%), the levels of FSH (98.3%) and LH (94.1%) were increased, and the levels of testosterone were normal (77.6%). There were 25 intracytoplasmic sperm injection (ICSI) treatment cycles using fresh testicular sperm and 22 ICSI treatment cycles using frozen testicular sperm. The rates of fertilization (63.5% fresh sperm vs 41.6% frozen sperm), implantation (37% fresh sperm vs 13.2% frozen sperm), clinical pregnancy (60.9% fresh sperm vs 19% frozen sperm), live birth delivery (52.2% fresh sperm vs 19% frozen sperm) and newborn (65.2% fresh sperm vs 23.8% frozen sperm) were higher in the group using fresh testicular sperm. Chromosome analysis of the 21 newborn was normal.

Limitations, reasons for caution

Although presenting a high number of cases with azoospermic non-mosaic Klinefelter syndrome treated with testicular sperm extraction and intracytoplasmic sperm injection, future studies are needed with a higher number of cycles using frozen testicular sperm, in order to confirm or rebut that the freezing methodology affects negatively the clinical outcomes.

Wider implications of the findings: Data adds further information regarding testicular sperm retrieval rates and use of fresh or frozen testicular sperm in Klinefelter syndrome (KS) patients. High newborn rates were obtained only with fresh testicular sperm. Results also reassure KS patients about the safety relative to any abnormal chromosomal transmission to the born children.

Trial registration number

Not applicable

P–042 Impact of semen parameters, sperm DNA fragmentation and sperm aneuploidy in male infertility

Study question

Should sperm aneuploidies and sperm DNA fragmentation (sDNAfrag) be included as valid tests in the routine investigation of male infertility?

Summary answer

Sperm DNA fragmentation was associated with male age, oligozoospermia (OZ), oligoteratozoospermia (OT), astenoteratozoospermia (AT) and oligoastenoteratozoospermia (OAT). Sperm aneuploidies were associated with OT and OAT.

What is known already

Semen parameters assist male infertility diagnosis and treatment, but sDNAfrag and aneuploidy analysis could add useful information, as abnormal values compromise fertility. To include these tests in the routine diagnosis it should be determined if behave as informative parameter and add information regarding the fertility status. For that, further studies comparing these tests to semen parameters are needed, since previous results are not consensual. Additionally, standardization of a sDNAfrag cut-off is needed, as different sample sizes and techniques originate distinct results. Also, until a standardization of the protocol is missing, a cut-off value should be defined for each laboratory.

Study design, size, duration

A retrospective and prospective investigation was performed, within a 12 years period (April 2007-December 2019). A total of 835 infertile males with a normal karyotype (46,XY) were included. Karyotyping and evaluation of sDNAfrag and sperm aneuploidies were made at a public Genetic unit. All normozoospermic (NZ) patients with a born child and patients whose infertility treatments were done due to female factors were selected from our database and used as controls (60 individuals).

Participants/materials, setting, methods

Semen analysis followed WHO–2010 guidelines. sDNAfrag was evaluated using the TUNEL assay. Sperm aneuploidies were detected using FISH (chromosomes 13, 18, 21, X, Y). Several tests were applied: correlations for linear associations between numerical variables, ANOVA for comparisons between means, Dunn-test for post-hoc comparisons. To determine the sDNAfrag cut-off value, the area under the ROC curve, sensitivity and specificity, were calculated, with the Youden-Index used to find a threshold that maximizes both sensitivity and specificity.

Main results and the role of chance

Regarding male age, it was observed a positive correlation with sperm concentration, a negative correlation with sperm vitality (VT) and hypoosmolality, and a positive correlation with sDNAfrag. Regarding sDNAfrag, it was observed negative correlation with sperm concentration, total progressive motility (TPM), morphology, VT and hypoosmolality. Regarding sperm aneuploidies, both total sperm aneuploidy and total sperm disomy exhibited a negative association with sperm concentration, TPM and morphology. It was also investigated whose groups of individuals could be indicated for sDNAfrag or sperm aneuploidy testing. The NZ group evidenced significant lower sDNAfrag, total sperm aneuploidy and total sperm disomy in relation to the non-NZ group. In the NZ group, sDNAfrag was significantly lower in relation to the OZ, OT, AT and OAT groups. The NZ group presented significant lower percentages of sperm aneuploidy in relation to the OT and OAT groups, and significant lower percentages of sperm disomy in relation to the OAT group. Additionally, sDNAfrag was positively correlated with total sperm aneuploidy and total sperm disomy. From the present large population, ROC curve analysis allowed estimating a cut-off value of 18.8% for the TUNEL-assay (sDNAfrag), with 0.658 of area under the curve, 53.9% sensitivity and 76.7% specificity.

Limitations, reasons for caution

Although presenting a high number of cases and strict controls, the present study was unable to include as controls healthy men with proven fertility. Additionally, the present study did not take into account life-style factors and male associated pathologies besides infertility.

Wider implications of the findings: Semen parameters were shown to be negatively correlated with sDNAfrag and sperm aneuploidies. As sDNAfrag testing and sperm aneuploidy testing were associated with semen abnormalities and male age, it is suggested their inclusion in the routine evaluation of infertile men, thus adding important complementary information about the fertility status.

Trial registration number

Not Appliable

Deregulation of imprinted genes expression and epigenetic regulators in placental tissue from intrauterine growth restriction

PURPOSE

Intrauterine growth restriction (IUGR) is a fetal growth complication that can be caused by ineffective nutrient transfer from the mother to the fetus via the placenta. Abnormal placental development and function have been correlated with abnormal expression of imprinted genes, which are regulated by epigenetic modifications at imprinting control regions (ICRs). In this study, we analyzed the expression of imprinted genes known to be involved in fetal growth and epigenetic regulators involved in DNA methylation, as well as DNA methylation at the KvDMR1 imprinting control region and global levels of DNA hydroxymethylation, in IUGR cases.

METHODS

Expression levels of imprinted genes and epigenetic regulators were analyzed in term placental samples from 21 IUGR cases and 9 non-IUGR (control) samples, by RT-qPCR. Additionally, KvDMR1 methylation was analyzed by bisulfite sequencing and combined bisulfite restriction analysis (COBRA) techniques. Moreover, global DNA methylation and hydroxymethylation levels were also measured.

RESULTS

We observed increased expression of PHLDA2, CDKN1C, and PEG10 imprinted genes and of DNMT1, DNMT3A, DNMT3B, and TET3 epigenetic regulators in IUGR placentas. No differences in methylation levels at the KvDMR1 were observed between the IUGR and control groups; similarly, no differences in global DNA methylation and hydromethylation were detected.

CONCLUSION

Our study shows that deregulation of epigenetic mechanisms, namely increased expression of imprinted genes and epigenetic regulators, might be associated with IUGR etiology. Therefore, this study adds knowledge to the molecular mechanisms underlying IUGR, which may contribute to novel prediction tools and future therapeutic options for the management of IUGR pregnancies.

X-chromosome inactivation: implications in human disease

X-chromosome inactivation (XCI) is a process involved in the pathogenesis of several diseases. In this mini review, we discuss the known mechanisms associated with XCI, when and how does it initiate, spreads and maintain, as well as the mechanisms that allow some genes to escape from it. We address the skewed XCI, condition in which the process are not fully randomized and its consequences to the phenotype of some pathologies. We debate about the known pathologies implicated, including X unbalanced rearrangements, X-autosomal balanced translocations, Turner and Klinefelter syndromes and also for X-linked diseases and its consequences in males and females. Some pathologies are discussed more in detail such as intellectual disability with a recognized relationship with XCI. Finally, possible future implications of genomic therapy and treatment of patients and list of areas that need further research on this topic are addressed.

46,XX male disorder of sexual development

An individual’s sexual phenotype is usually determined by the presence or absence of the Y chromosome in the embryo’s karyotype, however, due to abnormal X/Y terminal exchange through male meiosis, a few individuals develop male genitalia in the absence of the Y chromosome. This case report presents an adolescent referred to the Pediatric Endocrinology Unit due to bilateral gynecomastia. A diagnosis of hypergonadotropic hypogonadism was established and chromosomal analysis disclosed 46,XX karyotype, with the SRY gene locus found on one of his X chromosomes. A multidisciplinary approach, including psychological support and genetic counseling, is ideal for the management of these patients. Neoplastic transformation of the dysgenetic gonads has been described in several cases, and hence self-examinations and regular ultrasounds are commonly advised.

12q14 microduplication: a new clinical entity reciprocal to the microdeletion syndrome?

Background

12q14 microdeletion syndrome is characterized by low birth weight and failure to thrive, proportionate short stature and developmental delay. The opposite syndrome (microduplication) has not yet been characterized. Our main objective is the recognition of a new clinical entity - 12q14 microduplication syndrome. - as well as confirming the role of HMGA2 gene in growth regulation.

Case presentation

Array Comparative Genomic Hybridization (CGH), Karyotype, Fluorescence in situ Hybridization, Quantitative-PCR analysis and Whole exome sequencing (WES) were performed in a girl presenting overgrowth and obesity. Array CGH identified a 1.5 Mb 12q14.3 microduplication involving HMGA2, GRIP1, IRAK3, MSRB3 and TMBIM4 genes. Karyotype and FISH showed that duplication was a de novo insertion of 12q14.3 region on chromosome 9p resulting in an interstitial microduplication. Q-PCR confirmed the duplication only in the proband. WES revealed no pathogenic variants.

Conclusions

Phenotypic comparison with patients with 12q14 microdeletion syndrome showed a reciprocal presentation, suggesting a phenotypically recognizable 12q14 microduplication syndrome as well as confirming the role of HMGA2 gene in growth regulation. It is also indicative that other genes, such as IRAK3 and MSRB3 might have of role in weight gain and obesity.

Identification of Copy Number Variation by Array-CGH in Portuguese Children and Adolescents Diagnosed with Autism Spectrum Disorders

BACKGROUND

Autism spectrum disorders (ASD) affect many children with an estimated prevalence of 1%. Array-comparative genomic hybridization (CGH) offers significant sensitivity for the identification of submicroscopic chromosomal abnormalities and it is one of the most used techniques in daily practice. The main objective of this study was to describe the usefulness of array-CGH in the etiologic diagnosis of ASD.

METHODS

Two-hundred fifty-three patients admitted to a neurogenetic outpatient clinic and diagnosed with ASD were selected for array-CGH (4 × 180K microarrays). Public databases were used for classification in accordance with the American College of Medical Genetics Standards and Guidelines.

RESULTS

About 3.56% (9/253) of copy number variations (CNVs) were classified as pathogenic. When likely pathogenic CNVs were considered, the rate increased to 11.46% (29/253). Some CNVs apparently not correlated to the ASD were also found. Considering a phenotype-genotype correlation, the patients were divided in two groups. One group according to previous literature includes all the CNVs related to ASDs (23 CNVs present in 22 children) and another with those apparently not related to ASD (10 CNVs present in 7 children). In 18 patients, a next-generation sequencing (NGS) panel were performed. From these, one pathogenic and 16 uncertain significance variants were identified.

CONCLUSION

The results of our study are in accordance with the literature, highlighting the relevance of array-CGH in the genetic of diagnosis of ASD population, namely when associated with other features. Our study also reinforces the need for complementarity between array-CGH and NGS panels or whole exome sequencing in the etiological diagnosis of ASD.

Prenatal diagnosis: the clinical usefulness of array comparative genomic hybridization

Background

Array comparative genomic hybridization (aCGH) has been replacing karyotype in neurodevelopment diseases or intellectual disability cases. Regarding prenatal diagnosis (PND) karyotyping is still the criterion standard technique; nevertheless, the application of aCGH in this field has been increasing dramatically and some groups recommended it as the first-tier prenatal genetic test in cases of fetal ultrasound abnormalities. Despite aCGH greater resolution, the detection of variants of unknown significance (VOUS) is not desirable, so it's need some reflexion before generalized application on PND.

Objective

The aim of this study was to analyze the prevalence and type of copy number variants (CNVs) detected in the 55 PND samples collected from pregnancies with indication to perform aCGH.

Methods

aCGH was performed using Agilent 4 × 180K microarrays and results were analyzed using CytoGenomics software.

Results and conclusion

Eight (14.5%) cases had pathogenic or likely pathogenic CNVs. VOUS were found in 21.8% of the cases, but this frequency could be minimized if only large CNVs above 1 million base pairs that are outside the clinically curated targeted regions were considered.

Intellectual disability and overgrowth-A new case of 19p13.13 microdeletion syndrome with digital abnormalities

19p13.13 microdeletion has been consistently associated with intellectual disability, overgrowth, and macrocephaly. We report a 19p13.13 microdeletion, detected by array CGH, in a girl with moderate intellectual disability, overgrowth with macrocephaly, prominent digit pads and deep digital creases, hypotonia, ataxia, and strabismus. This clinical report helps to delineate the role of some of the deleted genes, as well as the phenotype of recently described 19p13.13 microdeletion syndrome, including the description of novel digital abnormalities.

Chromosome mis-segregation and cytokinesis failure in trisomic human cells

Cancer cells display aneuploid karyotypes and typically mis-segregate chromosomes at high rates, a phenotype referred to as chromosomal instability (CIN). To test the effects of aneuploidy on chromosome segregation and other mitotic phenotypes we used the colorectal cancer cell line DLD1 (2n = 46) and two variants with trisomy 7 or 13 (DLD1+7 and DLD1+13), as well as euploid and trisomy 13 amniocytes (AF and AF+13). We found that trisomic cells displayed higher rates of chromosome mis-segregation compared to their euploid counterparts. Furthermore, cells with trisomy 13 displayed a distinctive cytokinesis failure phenotype. We showed that up-regulation of SPG20 expression, brought about by trisomy 13 in DLD1+13 and AF+13 cells, is sufficient for the cytokinesis failure phenotype. Overall, our study shows that aneuploidy can induce chromosome mis-segregation. Moreover, we identified a trisomy 13-specific mitotic phenotype that is driven by up-regulation of a gene encoded on the aneuploid chromosome.

DOI:http://dx.doi.org/10.7554/eLife.05068.001

The DNA in a human cell is divided between forty-six structures called chromosomes. Before a cell divides, it copies every chromosome so that each daughter cell will have the same DNA as the parent cell. These chromosomes align in the center of the cell and then the matching chromosomes are separated and pulled to opposite ends.

However, in some cases the separation process does not work properly, which can produce cells that either have too many, or too few, chromosomes. Abnormal numbers of chromosomes within cells—called aneuploidy—is a leading cause of miscarriage and birth defects in humans. Aneuploidy is also a common feature of cancer cells.

It is common for the chromosomes in cancer cells to be distributed unequally when the cell divides. This phenomenon is known as chromosomal instability, but the link between aneuploidy and chromosomal instability in cancer cells is not fully understood.

Here, Nicholson et al. used live-cell imaging techniques to analyze healthy human cells and cancer cells that had either the normal forty-six chromosomes, or a defined extra chromosome. Nicholson et al. found that when the cells divided, the chromosomes in the cells that had an extra copy of chromosome 7 or 13 were more prone to distributing chromosomes unequally, compared to cells with a normal number of chromosomes.

Nicholson et al. also observed that the cells with an extra chromosome 13 were unable to properly divide into two. These cells had increased levels of a protein called Spartin—which is important for the last stage in cell division—and this was responsible for the failure to produce two daughter cells.

These findings show that aneuploidy can cause chromosomal instability in human cells. Furthermore, Nicholson et al. have identified a defect in cell division that is specifically caused by the presence of an extra chromosome 13 in human cells. A future challenge will be to determine how, and to what extent, different chromosomes can affect chromosome stability. This could be useful in the development of therapies against cancer cells with aneuploidy.

DOI:http://dx.doi.org/10.7554/eLife.05068.002

Relevance of genomic imprinting in intrauterine human growth expression of CDKN1C, H19, IGF2, KCNQ1 and PHLDA2 imprinted genes

PURPOSE

To study the relationship of imprinted gene expression (CDKN1C, H19, IGF2, KCNQ1 and PHLDA2) with human fetal growth.

METHODS

RNA was extracted from fetuses with intrauterine growth restriction (IUGR) and from the controls without growth restriction. The gene expression pattern of CDKN1C, H19, IGF2, KCNQ1 and PHLDA2 genes was evaluated using RT-PCR. MS-MLPA was also performed to assess the IC1 and IC2 DNA methylation status on chromosome 11p15.5.

RESULTS

The samples were divided according to their tissue type in placental or fetal tissue. Within each group, IUGR cases and controls were compared. In the IUGR cases, in both fetal and placental tissue groups IGF2 was observed to be down regulated. In another approach, the samples were divided in IUGR and control groups and for each of them placental and fetal tissue was compared. Within the IUGR group up regulation of CDKN1C, KCNQ1, and PHLDA2 was determined in placental samples. IUGR group presented a statistically lower methylation status in both IC1 and in IC2. Regarding differences between fetal and placental samples within this group, methylation status of placental samples was statistically significant down regulated in the imprinting center 1 (IC1).

CONCLUSIONS

Genomic imprinting is a phenomenon that plays an important role in fetal and placental development. This study emphasizes the importance of imprinted genes during pregnancy. Differences between tissues could reflect different mechanisms, either compensatory or adverse, that should be investigated in more detail.

Estudo da Prevalência de Anomalias Cromossómicas em Abortamentos Espontâneos ou Mortes Fetais

<strong>Introduction:</strong> Spontaneous abortion is one of the most frequent problems of pregnancy, estimated to affect, at least, one in every four women who tries to conceive. The main purpose of this work was to study the prevalence of chromosomal abnormalities in gestational losses, evaluating their relation with maternal age, gestational age and previous abortion history.<br /><strong>Material and Methods:</strong> Retrospective study of 401 pregnancy loss cases that have gone through cytogenetic and anatomopathologic analysis between January 2008 and June 2012, in Centro Hospitalar de S. João, Oporto.<br /><strong>Results:</strong> Of the 401 cases sent to cytogenetic study, it was possible to obtain information about the chromosomal complement in 333 cases, of which 72.7% showed normal karyotype, and 27.3% abnormal karyotype. Aneuploidies represented 92.3% of the identified chromosomopathies, with trisomies being the most frequent, related with an advanced maternal age and an early gestational age. There was no agreement between the results of the cytogenetic and the anatomopathologic analysis.<br /><strong>Discussion/Conclusion: </strong>The prevalence of chromosomal abnormalities, during the first trimester, is similar between sporadic and recurrent miscarriages. With increased maternal age, trisomies, the most frequent type of aneuploidy, are more likely to occur, with a mean increment in probability of 7.4% per year. A significant karyotype-pathological correlation was not established. Maternal contamination is the main obstacle to the accurate determination of the prevalence of chromosomal abnormalities. The molecular cytogenetic techniques already available can overcome the limitations of the conventional technique.

[Prevalence of chromosomal abnormalities in spontaneous abortions or fetal deaths]

INTRODUCTION

Spontaneous abortion is one of the most frequent problems of pregnancy, estimated to affect, at least, one in every four women who tries to conceive. The main purpose of this work was to study the prevalence of chromosomal abnormalities in gestational losses, evaluating their relation with maternal age, gestational age and previous abortion history.

MATERIAL AND METHODS

Retrospective study of 401 pregnancy loss cases that have gone through cytogenetic and anatomopathologic analysis between January 2008 and June 2012, in Centro Hospitalar de S. João, Oporto.

RESULTS

Of the 401 cases sent to cytogenetic study, it was possible to obtain information about the chromosomal complement in 333 cases, of which 72.7% showed normal karyotype, and 27.3% abnormal karyotype. Aneuploidies represented 92.3% of the identified chromosomopathies, with trisomies being the most frequent, related with an advanced maternal age and an early gestational age. There was no agreement between the results of the cytogenetic and the anatomopathologic analysis.

DISCUSSION/CONCLUSION

The prevalence of chromosomal abnormalities, during the first trimester, is similar between sporadic and recurrent miscarriages. With increased maternal age, trisomies, the most frequent type of aneuploidy, are more likely to occur, with a mean increment in probability of 7.4% per year. A significant karyotype-pathological correlation was not established. Maternal contamination is the main obstacle to the accurate determination of the prevalence of chromosomal abnormalities. The molecular cytogenetic techniques already available can overcome the limitations of the conventional technique.

Inv21p12q22del21q22 and intellectual disability

Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalance in offspring. Less than 3% of Down syndrome patients have duplication as a result of parental pericentric inversion of chromosome 21. We report a family with an apparently balanced pericentric inversion of chromosome 21. The proband, a 23-year-old female was referred for prenatal diagnosis at 16 weeks gestation because of increased nuchal translucency. She has a familial history of Down's syndrome and moderate intellectual disability, a personal history of four spontaneous abortions and learning difficulties. Peripheral blood and amniotic fluid samples were collected to perform proband's and fetus' cytogenetic analyses. Additionally, another six family members were evaluated and cytogenetic analysis was performed. Complementary FISH and MLPA studies were carried out. An apparent balanced chromosome 21 pericentric inversion was observed in four family members, two revealed a recombinant chromosome 21 with partial trisomy, and one a full trisomy 21 with an inverted chromosome 21. Array CGH analysis was performed in the mother and the brother's proband. MLPA and aCGH studies identified a deletion of about 1.7 Mb on the long arm of inverted chromosome 21q22.11. We believe the cause of the intellectual disability/learning difficulties observed in the members with the inversion is related to this deletion. The recombinant chromosome 21 has a partial trisomy including the DSCR with no deletion. The risk for carriers of having a child with multiple malformations/intellectual disability is about 30% depending on whether and how this rearrangement interferes with meiosis.

Normal sperm in a 2;2 homologous male translocation carrier

PURPOSE

Carriers of balanced structural chromosomal abnormalities are phenotypically normal but are at high risk of infertility. Translocations usually occur between two non-homologous chromosomes. When occur between homologous chromosomes, an extremely rare event, generally involve acrocentric chromosomes. We present an infertile male referred for genetic analysis with a pure balanced homologous 2;2 translocation and normal sperm in the ejaculate.

METHODS

Conventional cytogenetic and fluorescence in situ hybridization (FISH) were used in karyotype and sperm analysis, respectively.

RESULTS

Male's karyotype revealed a pure balanced translocation involving homologous chromosomes 2: 46,XY,t(2;2)(p23;q21.2). Sperm analysis by FISH revealed the presence of 15.8 % of normal and 84.2 % of abnormal spermatozoa for chromosome 2.

CONCLUSIONS

This is the first report of confined gonadal mosaicism in a pure homologous non-acrocentric chromosome translocation carrier. Preimplantation genetic diagnosis for chromosome 2 should be offered as a reproductive option.

Phenotypic expression in the first case of complete trisomy 12: combination of prenatal ultrasound and necropsic examination

The authors report the first case of a complete trisomy 12 detected antenatally at 16 weeks of gestation. The ultrasonographic features (craniofacial abnormalities) correlated well with postmortem findings. The absence of the hypophysis gland, olfactory pathways and both adrenal glands, as well as developmental anomalies of the central nervous system, were additional findings at autopsy. The recognition of complete trisomy 12 phenotype can be helpful in the pre- and postnatal diagnosis of future similar cases and parental counseling.

Clinicopathological features of 45,X/46,Xidic(Y) mosaicism and therapeutic implications: case report

CONTEXT

45,X/46,Xidic(Y) mosaicism demands careful and thorough study because of both its variable clinical features and its potential complications.

CASE REPORT

The present case relates to a three-year-old girl with the mosaic karyotype 46,X,idic(Y)(q11.2)[23]/45,X[6]. She had no signs of virilization or Turner's syndrome phenotype, but she was referred to our hospital because she presented reduced growth rate, abnormal facies and a melanotic nevus. After examination, she underwent prophylactic gonadectomy because of the risk of gonadoblastoma. Cytogenetic analysis on the streak gonads and blood showed significant differences in the 45,X cell line between these two tissues. The presence of the sex-determining region Y (SRY) gene did not determine male differentiation, which meant in the present case that the predominance of the X cell line in the gonadal tissue was probably due to the determining factor for female sexual differentiation.

Expression and function of sodium transporters in two opossum kidney cell clonal sublines

The present study describes characteristic features of two clonal subpopulations of opossum kidney (OK) cells (OK(LC) and OK(HC)) that are functionally different but morphologically identical. The most impressive differences between OK(HC) and OK(LC) cells are the overexpression of Na+-K+-ATPase and type 3 Na+/H+ exchanger by the former, accompanied by an increased Na+-K+-ATPase activity (57.6 +/- 5.6 vs. 30.0 +/- 0.1 nmol P(i). mg protein(-1). min(-1)); the increased ability to translocate Na+ from the apical to the basolateral surface; and the increased Na+-dependent pH(i) recovery (0.254 +/- 0.016 vs. 0.094 +/- 0.011 pH units/s). Vmax values (in pH units/s) for Na+-dependent pHi recovery in OK(HC) cells (0.00521 +/- 0.0004) were twice (P < 0.05) those in OK(LC) (0.00202 +/- 0.0001), with similar Km values (in mM) for Na+ (OK(LC), 21.0 +/- 5.5; OK(HC), 14.0 +/- 5.6). In addition, we measured the activities of transporters (organic ions, alpha-methyl-D-glucoside, L-type amino acids, and Na+ and enzymes (adenylyl cyclase, aromatic L-amino acid decarboxylase, and catechol-O-methyltransferase). The cells were also characterized morphologically by optical and scanning electron microscopy and karyotyped. It is suggested that OK(LC) and OK(HC) cells constitute an interesting cell model for the study of renal epithelial physiology and pathophysiology, namely, hypertension.

Chronic eosinophilic leukaemia presenting with erythroderma, mild eosinophilia and hyper-IgE: clinical, immunological and cytogenetic features and therapeutic approach. A case report

A 23-year-old, white male metallurgist presented with pruritic erythematous maculo-papules over the trunk and upper limbs and 6 months later developed erythroderma, eosinophilia and multi-organ dysfunction. A diagnosis of chronic eosinophilic leukaemia was made on the basis of myeloproliferative involvement of both peripheral blood and bone marrow, associated with eosinophilic differentiation and a t(5;12)(q33;p13) translocation. The initial therapeutic approach was interferon alfa-2b plus cytosine arabinoside, for 13 months, followed by hydroxyurea plus vincristine. There was improvement of skin lesions, disappearance of eosinophilia and decrease of serum immunoglobulin E, towards normal values.

Detection of prognostic significant translocations in childhood acute lymphoblastic leukaemia by one-step multiplex reverse transcription polymerase chain reaction

The search for chromosomal translocations in de novo cases of childhood acute lymphoblastic leukaemia (ALL) is crucial for the selection of the appropriate therapeutic protocol. In this work, we describe a new method - one-step multiplex reverse transcription polymerase chain reaction (RT-PCR) - to screen for prognostic significant translocations in childhood ALL. Our approach involves a single PCR reaction for the simultaneous detection of the molecular rearrangements resulting from the t(9;22), t(12;21), t(4;11) and t(1;19), with a turnaround time of less than 24 h. This assay proved to be highly sensitive, specific, reproducible and easy to implement in a routine genetics laboratory.