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Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy. A distinctive characteristic of KS is oligozoospermia. Despite multiple studies that have described the natural history of the degenerative process of germ cells in patients with KS, the molecular mechanisms that initiate this process are not well characterized. MicroRNA (miRNA)-mediated post-transcriptional control mechanisms have been increasingly recognized as important regulators of spermatogenesis; however, only a few studies have evaluated the role of miRNAs in the gonadal failure of these patients. Here, we describe a differential expression profile for the miRNAs in testicular tissue samples taken from KS patients. We analysed testicular tissue samples from 4 KS patients and 5 control patients (obstructive azoospermia) through next-generation sequencing, which can provide information about the mechanisms involved in the degeneration of germ cells. A distinctive differential expression profile was identified for 166 miRNAs in the KS patients: 66 were upregulated, and 100 were downregulated. An interactome analysis was performed for 7 of the upregulated and the 20 downregulated miRNAs. The results showed that the target genes are involved in the development, proliferation, and differentiation processes of spermatogenesis, which may explain their role in the development of infertility. This is the first report of a miRNA expression profile generated from testicular tissue samples of KS patients. Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy in humans, with a prevalence of 1:500 live births 1. It was first described in 1942 as a syndrome characterized by gynaecomastia, azoospermia, and elevated levels of follicle-stimulating hormone (FSH) 2. The presence of an extra X chromosome (47,XXY) in the standard male chromosome set (46,XY) causes Klinefelter syndrome. Chromosomal nondisjunction during meiosis or early embryonic mitosis causes this aneuploidy. Cytogenetic confirmation of aneuploidy is performed through conventional karyotype analysis. Approximately 85-90% of KS patients present with a 47,XXY chromosome set, while the remaining 10-15% of patients present with mosaicism (47,XXY/46,XY) or aneuploidies with more than three sex chromosomes (48,XXXY or 48,XXYY) 3,4. Sexual development in KS patients may be healthy before puberty, showing typical pubertal changes and levels of luteinizing hormone (LH), FSH, and testosterone 5. During adolescence, the testicles appear small and firm and the patient presents with multiple symptoms of androgen deficiency. Hypogonadotropic hypogonadism (HH) is the predominant characteristic, with testosterone levels below 12 nmol/L; low levels of insulin-like 3 (INSL 3), inhibin B and anti-Müllerian hormone (AMH); and high levels of FSH and LH 6. Infertility is one of the distinctive characteristics of KS, found in approximately 10% of azoospermia patients. During puberty, the testicles of KS patients grow to a volume of 6 ml; however, although the serum levels of testosterone increas...

The early detection of congenital anomaly epidemics occurs when comparing current with previous frequencies in the same population. The success of epidemiologic surveillance depends on numerous factors, including the accuracy of the rates available in the base period, wide population coverage, and short periodicity of analysis. This study aims to describe the Latin American network of congenital malformation surveillance: ReLAMC, created to increase epidemiologic surveillance in Latin America. We describe the main steps, tasks, strategies used, and preliminary results. From 2017 to 2019, five national registries (Argentina [RENAC], Brazil [SINASC/SIM‐BRS], Chile [RENACH], Costa Rica [CREC], Paraguay [RENADECOPY‐PNPDC]), six regional registries (Bogotá [PVSDC‐Bogota], Cali [PVSDC‐Cali], Maule [RRMC SSM], Nicaragua [SVDC], Nuevo‐León [ReDeCon HU], São Paulo [SINASC/SIM‐MSP]) and the ECLAMC hospital network sent data to ReLAMC on a total population of 9,152,674 births, with a total of 101,749 malformed newborns (1.1%; 95% CI 1.10–1.12). Of the 9,000,651 births in countries covering both live and stillbirths, 88,881 were stillborn (0.99%; 95% CI 0.98–0.99), and among stillborns, 6,755 were malformed (7.61%; 95% CI 7.44–7.79). The microcephaly rate was 2.45 per 10,000 births (95% CI 2.35–2.55), hydrocephaly 3.03 (2.92–3.14), spina bifida 2.89 (2.78–3.00), congenital heart defects 15.53 (15.27–15.79), cleft lip 2.02 (1.93–2.11), cleft palate and lip 2.77 (2.66–2.88), talipes 2.56 (2.46–2.67), conjoined twins 0.16 (0.14–0.19), and Down syndrome 5.33 (5.18–5.48). Each congenital anomaly showed heterogeneity in prevalence rates among registries. The harmonization of data in relation to operational differences between registries is the next step in developing the common ReLAMC database.

BackgroundGenetic association studies for gastroschisis have highlighted several candidate variants. However, genetic basis in gastroschisis from noninvestigated heritable factors could provide new insights into the human biology for this birth defect. We aim to identify novel gastroschisis susceptibility variants by employing whole exome sequencing (WES) in a Mexican family with recurrence of gastroschisis.MethodsWe employed WES in two affected half‐sisters with gastroschisis, mother, and father of the proband. Additionally, functional bioinformatics analysis was based on SVS–PhoRank and Ensembl–Variant Effect Predictor. The latter assessed the potentially deleterious effects (high, moderate, low, or modifier impact) from exome variants based on SIFT, PolyPhen, dbNSFP, Condel, LoFtool, MaxEntScan, and BLOSUM62 algorithms. The analysis was based on the Human Genome annotation, GRCh37/hg19. Candidate genes were prioritized and manually curated based on significant phenotypic relevance (SVS–PhoRank) and functional properties (Ensembl–Variant Effect Predictor). Functional enrichment analysis was performed using ToppGene Suite, including a manual curation of significant Gene Ontology (GO) biological processes from functional similarity analysis of candidate genes.ResultsNo single gene‐disrupting variant was identified. Instead, 428 heterozygous variations were identified for which SPATA17, PDE4DIP, CFAP65, ALPP, ZNF717, OR4C3, MAP2K3, TLR8, and UBE2NL were predicted as high impact in both cases, mother, and father of the proband. PLOD1, COL6A3, FGFRL1, HHIP, SGCD, RAPGEF1, PKD1, ZFHX3, BCAS3, EVPL, CEACAM5, and KLK14 were segregated among both cases and mother. Multiple interacting background modifiers may regulate gastroschisis susceptibility. These candidate genes highlight a role for development of blood vessel, circulatory system, muscle structure, epithelium, and epidermis, regulation of cell junction assembly, biological/cell adhesion, detection/response to endogenous stimulus, regulation of cytokine biosynthetic process, response to growth factor, postreplication repair/protein K63‐linked ubiquitination, protein‐containing complex assembly, and regulation of transcription DNA‐templated.ConclusionConsidering the likely gene‐disrupting prediction results and similar biological pattern of mechanisms, we propose a joint “multifactorial model” in gastroschisis pathogenesis.

Case seriesPatient: —Final Diagnosis: Ellis van Creveld syndromeSymptoms: Conical teeth • polydactyly • short statureMedication: —Clinical Procedure: —Specialty: Pediatrics and NeonatologyObjective:Rare diseaseBackground:Ellis-van Creveld syndrome is an autosomal recessive chondro-ectodermal dysplasia characterized by disproportionate short stature, limb shortening, narrow chest, postaxial polydactyly and dysplastic nails and teeth. In addition, 60% of cases present congenital heart defects. Ellis-van Creveld syndrome is predominantly caused by mutations in the EVC or EVC2 (4p16) genes, with only a few cases caused by mutations in WDR35.Case Report:Here, we report on two Mexican families with patients diagnosed with Ellis-van Creveld syndrome. Family 1 includes four patients: three females of 15, 18, and 23 years of age and a 7-year old male. Family 2 has only one affected newborn male. All patients exhibited multiple features including hypodontia, dysplastic teeth, extra frenula, mild short stature, distal limb shortening, postaxial polydactyly of hands and feet, nail dystrophy, and knee joint abnormalities. Only two patients had an atrial septal defect. In all cases, molecular analysis by Sanger sequencing identified the same homozygous mutation in exon 12 of EVC, c.1678G>T, which leads to a premature stop codon.Conclusions:The mutation c.1678G>T has been previously reported in another Mexican patient and it appears to be a recurrent mutation in Mexico which could represent a founder mutation. The large number of patients in this case allows the clinical variability and spectrum of manifestations present in individuals with Ellis-van Creveld syndrome even if they carry the same homozygous mutation in a same family.