Puberty is a complex transitional phase in which reproductive capacity is achieved. There is a very wide variation in the age range of the onset of puberty, which follows a familial, ethnic, and sex pattern. The hypothalamic-pituitary-gonadal axis and several genetic, environmental, and nutritional factors play an important role in the onset of and throughout puberty. Recently, there has been significant progress in identifying factors that affect normal pubertal timing. Different studies have identified single nucleotide polymorphisms (SNPs) that affect pubertal timing in both sexes and across ethnic groups. Single genes are implicated in both precocious and delayed puberty, and epigenetic mechanisms have been suggested to affect the development and function of the GnRH neuronal network and responsiveness of end organs. All these factors can influence normal puberty timing, precocious puberty, and delayed puberty. The objective of this review is to describe recent findings related to the genetic and epigenetic control of puberty and highlight the need to deepen the knowledge of the regulatory mechanisms of this process in the normal and abnormal context.

Background: DNA methylation alterations represent a key epigenetic mechanism linking environmental exposures to disease pathogenesis. The present study aimed to identify differentially methylated genes and shared biological processes associated with lung cancer (LuCa), chronic obstructive pulmonary disease (COPD) and tobacco exposure. Methods: A comprehensive literature search was performed in PubMed to identify studies evaluating DNA methylation in LuCa, COPD and smoking-related models. A total of 117 articles were selected, including 83 studies on lung cancer, 18 on COPD and 16 on smoking exposure. Genes exhibiting statistically significant methylation changes relative to controls were extracted from each study. To provide additional support for these findings, differential methylation signatures were further evaluated using The Cancer Genome Atlas (TCGA) lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) datasets. Functional and transcription factor motif enrichment analyses were subsequently conducted to identify shared biological pathways and regulatory mechanisms. Results: In total, 324 genes displaying altered methylation patterns across these conditions were identified. Seven tumor suppressor genes (CDKN2A, CDH13, MGMT, MIR137, DAPK1, RARB, and RASSF1A) consistently exhibited hypermethylation in both lung cancer and in association with smoking exposure. In addition, AHRR hypomethylation emerged as a shared epigenetic hallmark across all three conditions. TCGA-based analyses confirmed several of these methylation patterns and revealed subtype-specific methylation profiles associated with smoking history. Functional enrichment highlighted common biological processes and signaling pathways, particularly those related to transcriptional regulation, apoptosis and cancer-associated pathways. Conclusions: These results provide an integrative overview of shared DNA methylation alterations associated with smoking exposure, COPD, and lung cancer, and suggest potential DNA methylation candidates that may be relevant for future biomarker development and mechanistic studies.

Isodicentric Y chromosome [idic(Y)] is one of the most common structural abnormalities of the Y chromosome and has been observed in patients with reproductive disorders and in patients with disorders of sexual development. Most idic(Y) chromosomes are found in mosaic form with a 45,X cell line. These chromosomes are highly unstable during mitosis due to the presence of 2 centromers, which explains their probable loss in early mitosis or mitosis of the embryo and therefore the presence of the 45,X line. It has been hypothesized that the proportion of 45,X cells in various tissues probably influences the phenotypic sex of individuals carrying an idic(Y) chromosome, ranging from infertile men, hypospadias, ambiguous genitalia, and Turner syndrome to sex reversal. In this article we present 5 cases of patients with idic(Y) referred for suspected disorder of sex development (DSD), 3 with a male assignment and 2 with a female assignment. All cases have variable clinical characteristics, which were assessed by the transdisciplinary group of Disorders of Sex Development of the Hospital Universitario San Ignacio, Bogotá, Colombia. Patients were analyzed by conventional and molecular cytogenetics using high-resolution G-band and FISH techniques. Our findings highlight the importance of cytogenetic studies in the diagnosis of DSD patients.

Resumen Objetivos: La etiología de la disgenesia gonadal y el síndrome ovotesticular se desconoce en la mayoría de los casos. Para realizar la caracterización citogenética y molecular de un grupo de pacientes con síndrome ovotesticular y disgenesia gonadal completa a partir de muestras de sangre periférica y tejido gonadal. Material y métodos: Se incluyeron un total de 6 pacientes, 3 con diagnóstico de síndrome ovotesticular 46, XX, uno diagnosticado con 46, XY síndrome ovotesticular; uno con sospecha de disgenesia gonadal 46, XX y otro con disgenesia gonadal completa 46, XY. Resultados Todos los pacientes fueron evaluados con cariotipo, hibridación in situ fluorescente (FISH) para SRY, amplificación de sonda dependiente de ligación múltiple (MLPA) e hibridación genómica comparativa (aCGH) en muestras de sangre periférica. En los casos con tejido gonadal disponible, los niveles de expresión genética de SOX3, SRY y SOX9 se determinaron mediante PCR en tiempo real e inmunofluorescencia. Se descartaron reordenamientos relacionados con el gen SRY. No se detectaron deleciones/duplicaciones o variaciones en el número de copias (NVC) como etiología del trastorno del desarrollo sexual en ninguno de los pacientes estudiados. En un caso de síndrome ovotesticular 46, XX, el cariotipo gonadal era diferente del cariotipo en sangre periférica. Se observó expresión aberrante de SOX3 y SOX9 en tejido gonadal de un caso con síndrome ovotesticular 46, XX. Conclusiones: Se documentaron niveles más bajos de expresión de SRY y SOX9 en comparación con los niveles en líneas celulares humanas de testículo embrionario y Sertoli en el tejido gonadal de un caso con síndrome ovotesticular 46, XY. Los estudios citogenéticos y moleculares de las gónadas como complemento del estudio de sangre periférica tienen el potencial de enriquecer la comprensión de los trastornos del desarrollo sexual en pacientes que son XX o XY en sangre periférica.

E-cigarettes contain nicotine, propylene glycol, glycerol, and flavorings. The use of e-cigarettes has increased worldwide, especially among young people. Although the chemical compounds present in aerosols affect epigenetic mechanisms such as DNA methylation and generate genotoxicity, additional studies are needed to demonstrate their impact on human health. We evaluated the transcriptomic profile of peripheral blood mononuclear cells from users of electronic nicotine delivery systems. A cross-sectional observational study was conducted in which transcriptomes of peripheral blood mononuclear cells from e-cigarette users were sequenced, analyzed and classified according to their use into exclusive users (n = 4), mixed users (n = 4), and controls (n = 7). The analysis of differentially expressed genes was performed with DESeq2. The differentially expressed genes identified were experimentally validated by qPCR in a cohort of 64 research subjects. Four differentially expressed genes were detected in the exclusive users, and 44 genes were detected in the mixed users. No common differentially expressed genes between the two groups of users were identified. Among the differentially expressed genes detected in the exclusive and mixed users, tumor suppressor genes and different oncogenes whose functions are associated with relevant biological processes, such as cell adhesion, cell attachment, the endoplasmic reticulum, epithelialmesenchymal transition, neuronal development, the immune response, and carcinogenesis, were identified. Electronic cigarette consumption significantly impacts gene expression, with relevant biological functions in normal and pathological contexts. These findings provide new evidence on the health effects of vaping and the short-term impact resulting from the consumption of these products.