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.

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.

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.

Klinefelter syndrome: The characterization of the clinical and sociological features of 51 patients / Síndrome de Klinefelter: caracterización de los rasgos clínicos y sociológicos de 51 pacientes

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. (AU)

Introducción: El síndrome de Klinefelter es la aneuploidía más frecuente entre los pacientes varones. Su presentación clínica es muy heterogénea, por lo que supone un reto para su diagnóstico oportuno. Métodos: Se realizó un estudio retrospectivo con 51 pacientes seleccionados consecutivamente con diagnóstico de Síndrome de Klinefelter desde enero de 2010 hasta diciembre de 2019. Los cariotipos se identificaron mediante bandeo GTL de alta resolución en el Departamento de Genética. Se estudiaron múltiples parámetros clínicos y sociológicos mediante la recogida de datos de las historias clínicas. Resultados: De los 51 pacientes, 44 (86%) presentaron un cariotipo clásico (47,XXY) y siete (14%) evidenciaron mosaicismo. La edad media al diagnóstico fue de 30,2 ± 14,3 años. En cuanto al nivel de estudios (n = 44), 26 pacientes (59,1%) no tenían estudios secundarios, y cinco (11,4%) habían concluido estudios universitarios. Casi dos tercios de la muestra revelaban dificultades de aprendizaje (25/38) y algún grado de discapacidad intelectual estaba presente en 13,6% (6/44). La mitad de los pacientes eran trabajadores no cualificados (19,6%) o trabajadores de la industria, la construcción y los oficios (30,4%), que son empleos que característicamente requieren un bajo nivel educativo. La proporción de pacientes en paro era de 6,5%. Las principales quejas eran la infertilidad (54,2%), seguida de problemas relacionados con el hipogonadismo (18,7%) y la ginecomastia (8,3%); 10 pacientes (23,8%, n = 42) eran padres biológicos. En cuanto a la cuestión de la fertilidad, se utilizaron técnicas de reproducción asistida en 39,6% de los sujetos estudiados (n = 48), con una tasa de éxito (un bebé para llevar a casa) de 57,9% (11/19), dos con semen de donante y nueve con gametos propios de los pacientes. Solo 41% de los pacientes (17/41) fueron tratadas con testosterona. (AU)

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.

Copy number variations on chromosome 2: impact on human phenotype, a cross-sectional study.

Background: Copy number variations (CNVs) on chromosome 2 are associated with a variety of human diseases particularly neurodevelopmental disorders. Array comparative genomic hybridization (aCGH) constitutes an added value for the diagnosis of neurodevelopmental or neuropsychiatric diseases. This study aims to establish a genotype-phenotype correlation, reporting CNVs on the chromosome 2, contributing for a better characterization of the molecular significance of rare CNVs in this chromosome. Methods: To accomplish this, a cross-sectional study was performed using genetic information included in a database of the Department of Genetics of the Faculty of Medicine and clinical data from Hospital database. CNVs were classified as pathogenic, benign, variants of unknown significance, and likely pathogenic or likely benign, in accordance with the ACMG Standards and Guidelines. Results: A total of 2897 patients were studied using aCGH, 32 with CNVs on chromosome 2, 24 classified as likely pathogenic, and 8 as pathogenic. Genomic intervals with a higher incidence were one 2p25.3 and 2q13 regions. Conclusions: This study will help to establish new genotype-phenotype correlations, allowing update of databases and literature and the improvement of diagnosis and genetic counseling which could be an added value for prenatal genetic counseling.

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.

Prenatal diagnosis study using array comparative genomic hybridization for genotype-phenotype correlation in 772 fetuses.

OBJECTIVE: The aim was to evaluate the main indications for prenatal diagnosis, the prevalence of abnormal copy number variations (CNVs), correlate them with clinical findings, analyze the prevalence of VUS, report the rare variants found and additionally highlight the clinical importance of microarray-based comparative genomic hybridization (aCGH) in prenatal diagnosis. STUDY DESIGN: We retrospectively analyzed a cohort of 772 fetuses with indication for genetic study in two tertiary hospitals, in a 9-years-period, using aCGH. RESULTS: Our results demonstrated 8.3 % (6.4-10.5 %, 95 % CI) detection rate of pathogenic CNVs. Within this group, the main indication was structural malformations (57 %) mainly involving central nervous system, skeletal and cardiac systems. Pathogenic results in cases with multiple malformations were higher than in cases with isolated anatomical system malformations showing statistical significant differences (p < 0.001). The second indication where we found more pathogenic CNVs was increased nuchal translucency (5-6.4 mm). In fact, the rate of pathogenic CNVs did not show significant differences between structural and non-structural malformations (p > 0.001), highlighting the relevance of genetic study by aCGH also in cases with no structural malformations. A total of 217 fetuses with CNVs classified as VUS were identified, mainly involving chromosomes X, 1 and 16. CONCLUSION: Our findings demonstrate 4.9 % (4.2-5.6 %, 95 % CI) increased in the diagnostic yield using aCGH compared to the use of conventional karyotype alone, confirming that the aCGH can improve the accuracy of prenatal diagnosis. Our survey provides a full genotype-phenotype analysis that can be clinically useful for the classification of variants in the context of prenatal setting, helping to provide a better reproductive genetic counselling.

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.

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.

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.

Premature ovarian insufficiency: clinical orientations for genetic testing and genetic counseling.

Premature ovarian insufficiency (POI) is a heterogeneous disorder diagnosed in women before 40 years old and describes a wide range of impaired ovarian function, from diminished ovarian reserve to premature ovarian failure. Genetic etiology accounts for 20% to 25% of patients. The evidence that POI can be isolated (nonsyndromic) or part of a pleiotropic genetic syndrome highlights its high heterogeneous etiology. Chromosomal abnormalities as a cause of POI have a prevalence of 10% to 13%, being 45,X complement the most common cytogenetic cause of primary amenorrhea and mosaicism with a 45,X cell line more frequently associated with secondary amenorrhea. Other X chromosome aberrations include deletions, duplications, balanced, and unbalanced X-autosome rearrangements involving the critical region for the POI phenotype (Xq13-Xq21 to Xq23-Xq27). The identification of 2 or more pathogenic variants in distinct genes argues in favor of a polygenic origin for POI. Hundreds of pathogenic variants (including mitochondrial) have been involved in POI etiology mainly with key roles in biological processes in the ovary, such as meiosis and DNA damage repair mechanism, homologous recombination, follicular development, granulosa cell differentiation and proliferation, and ovulation. The most common single gene cause for POI is the premutation for FMR1 gene (associated with fragile X syndrome) with alleles ranging from about 55 to about 200 CGG trinucleotide repeats. POI occurs in 20% of women with this premutation. As females with premutation or full mutation alleles are also at risk of having affected children, their genetic counseling should include the indication for prenatal diagnosis or preimplantation genetic testing after intracytoplasmic sperm injection and trophectoderm biopsy. In conclusion, in clinical practice high-resolution karyotype and FMR1 gene molecular study should be performed as first-tier tests in the assessment of POI. In addition, array Comparative Genomic Hybridization or specific next generation sequencing panels should be considered to identify chromosomal deletions/duplications under karyotype resolution or other pathogenic variants in specific genes associated with POI. This is particularly important in patients with first- or second-degree relatives also affected with POI, improving their reproductive and genetic counseling.

Relevancia de los arrays de hibridación genómica comparada en el estudio de los retrasos del desarrollo en pediatría / Array-CGH: importance in the study of developmental delays in pediatrics

INTRODUCCIÓN: El retraso general del desarrollo (RGD) constituye un trastorno intelectual y del comportamiento adaptativo que aparece en los niños menores de 5 años que no consiguen alcanzar los hitos del desarrollo normal. La discapacidad intelectual se caracteriza por la limitación en el funcionamiento intelectual y en el comportamiento adaptativo, surgida en la infancia. Entre las causas frecuentes y reconocibles del RGD y de la discapacidad intelectual se encuentran los desequilibrios cromosómicos. Los arrays de hibridación genómica comparada (aCGH) han contribuido a mejorar la tasa de detección de las anomalías genéticas y ya se consideran la prueba genética de elección para la discapacidad intelectual de origen desconocido. OBJETIVO: Analizar los resultados del estudio genético con aCGH motivado por un RGD o una discapacidad intelectual en pacientes pediátricos. PACIENTES Y MÉTODOS: Análisis retrospectivo de pacientes pediátricos sometidos a seguimiento ambulatorio que fueron objeto de un estudio genético con aCGH entre 2012 y 2017. RESULTADOS: El número de pacientes sometidos al estudio con aCGH ascendió a 215. Del total, el 64,2% fueron investigados por discapacidad intelectual, y el 35,8%, por RGD. El 23,3% presentó deleciones o duplicaciones en la aCGH; el 56%, por la discapacidad intelectual; y el 44%, por el RGD, y los cromosomas 16, 22, 2 y 1 fueron los implicados con más frecuencia. CONCLUSIÓN: El presente estudio demuestra la mayor prevalencia de ambos en el sexo masculino, en consonancia con otras publicaciones precedentes. La tasa de detección de las anomalías clasificadas como patógenas resultó superior a la notificada en otros estudios

INTRODUCTION: Global developmental delay (GDD) is an intellectual and adaptive impairment in infants under 5 years of age who fail to meet expected developmental milestones. Intellectual disability is characterized by limitation in intellectual function and adaptive behavior, with onset in childhood. Frequent identifiable causes of GDD and intellectual disability are chromosomal imbalances. The array comparative genomic hybridization (aCGH) has contributed to improve the detection rate of genetic abnormalities and is considered the first-tier genetic test for unexplained intellectual disability. AIM: To analyze the results of a genetic study by aCGH due to GDD or intellectual disability in pediatric patients. PATIENTS AND METHODS: Retrospective analysis of pediatric patients followed in outpatient, which underwent a genetic study by aCGH, from 2012 to 2017. RESULTS: 215 patients were studied by aCGH. Of the total, 64.2% were investigated for intellectual disability and 35.8% for GDD. A 23.3% presented aCGH deletions or duplications, 56% for intellectual disability and 44% for GDD, with chromosomes 16, 22, 2 and 1 being the most implicated. CONCLUSION: Our study demonstrated a higher prevalence in males, according to previously published reports. The rate of detection abnormalities classified as pathogenic was higher than in other studies

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.

Altered expression of epigenetic regulators and imprinted genes in human placenta and fetal tissues from second trimester spontaneous pregnancy losses.

Epigenetic mechanisms such as genomic imprinting have a fundamental role in embryo and fetal development. Hence, we here studied expression levels of epigenetic modifiers and imprinted genes in cases of ididopathic spontaneous abortion (SA). Thirty-five placental samples and 35 matched fetal tissues from second trimester SA were analysed; including 16 controls (placental and fetal infections as the known cause of spontaneous abortion) and 19 idiopathic SA cases. Transcript levels of epigenetic regulators and imprinted genes were measured by qRT-PCR and methylation at imprinted genes was studied by bisulfite genomic sequencing and MS-MLPA. Global DNA hydroxymethylation (5-hmC) levels were measured by an ELISA-based assay. We observed an upregulation of TET2 and TET3 in placental samples from idiopathic SA cases; however, no significant difference in global 5-hmC levels was observed. On the contrary, in fetal tissues, TET3 was markedly downregulated in idiopathic SA, showing an opposite trend to that observed in placental tissue. IGF2 and CDKN1C were upregulated and MEST downregulated in placentas from idiopathic SA cases; concordantly, IGF2 was also upregulated in fetal tissues from idiopathic SA cases. Although not reaching statistical significance, an increase in methylation levels of MEST, KvDMR1 and H19 DMRs was observed in idiopathic SA cases, concordantly with the observed changes in expression. Our study reveals, for the first time, deregulation of epigenetic modifiers and imprinted genes in both placental and fetal tissues from idiopathic SA cases in the second trimester of pregnancy, indicating a critical role during pregnancy.

Reproductive success of assisted reproductive technology in couples with chromosomal abnormalities.

PURPOSE: Infertility is estimated to affect 15% of couples, having chromosome abnormalities an important role in its etiology. The main objective of this work was to access the reproductive success of ART in infertile couples with chromosomal abnormalities comparing to a control group with normal karyotype. METHODS: A 7-year retrospective karyotype analysis of infertile couples was done. Data regarding type of infertility, couples' ages, ART performed, and their reproductive success were obtained. Adjusted odds ratio (OR) were used to estimate magnitude of association between the reproductive success and the different groups. RESULTS: We found a prevalence of 7.83% of chromosome abnormalities in our population (233 couples out of 2989). Chromosomal anomalies were found in 82 men (34.75%) and 154 women (65.25%), with low-grade mosaicism being the most prevalent (50.85%), followed by autosomal translocations (17.37%) and sex chromosomes abnormalities (13.56%). Only 2359 couples were treated with ART. There was a non-significant lower reproductive success rate in the cases (OR = 0.899, p = 0.530) with IVF providing the higher success rate. In general, female carriers of chromosome anomalies had a higher success rate, although not significant. CONCLUSION: Although the differences regarding success rate between groups were not found statistically significant, we still advocate that cytogenetic analysis should be performed routinely in all infertile couples namely before ART. This might help deciding the best treatment options including Preimplantation Genetic Testing for aneuploidies or structural rearrangements and minimize the risk of transmission of anomalies to the offspring.

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.