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CHORIONIC VILLUS SAMPLING AND AMNIOCENTESIS 🎗

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"Prenatal diagnosis has transformed the practice of medical genetics.” - Dr. Aubrey Milunsky 🧬 Chorionic villus sampling (CVS) and amniocentesis remain two epitomic invasive procedures in prenatal genetic diagnosis. Unlike screening approaches such as ultrasound and cell-free DNA testing, they provide diagnostic fetal-derived material for chromosomal and molecular analysis.      🔹 Chorionic villus sampling (CVS) is generally performed at 10–13 weeks of gestation. Chorionic villi are obtained from the placenta through a transabdominal or transcervical approach under ultrasound guidance. The sample can support karyotyping, chromosomal microarray, and targeted molecular testing, enabling relatively early diagnosis of conditions such as trisomy 21, 18 and 13, as well as selected single-gene disorders.       🔹 Amniocentesis is typically performed from 15 weeks onward. A small volume of amniotic fluid is collected transabdominally under ultrasound ...

WEEKEND READS 📚

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Recommended book of the weekend: 🍃 ☕ ➡️ "CHILDREN OF TIME By Adrian Tchaikovsky    🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁

REPRODUCTIVE GENETICS: GAMETOGENESIS, MEIOSIS, FERTILIZATION AND GENETIC VARIATION 🎗️

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“Every independently conceived person is biologically and genetically different.” Professor Kenneth K. Kidd 🧬 Reproductive genetics examines how genetic information is transmitted and reshuffled during human reproduction. Gametogenesis, meiosis, fertilization and genetic variation are interconnected processes that generate genetically distinct offspring while maintaining the chromosome complement of the species. 🔹 Gametogenesis produces haploid gametes from germ cells. Spermatogenesis generates spermatozoa in the testes, whereas oogenesis produces mature oocytes in the ovaries. Through these processes, human gametes normally acquire 23 chromosomes, preparing them for the restoration of diploidy at fertilization. 🔹 Meiosis is the specialized cell division underlying gamete formation. After one round of DNA replication, meiosis I separates homologous chromosomes and meiosis II separates sister chromatids. During prophase I, homologous chromosomes undergo recombination a...

WEEKEND READS 📚

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Recommended book of the weekend: 🍃 ☕ ➡️ "BLOOD MUSIC" By Greg Bear   🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁

DNA METHYLATION & EPIGENETIC REGULATION: CPG ISLANDS, DNMTS, TET ENZYMES & METHYLATION PATTERNS 🎗

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“DNA methylation is an epigenetic mark” involved in regulating transcription and maintaining cellular identity. -Dr. Peter A. Jones 🧬 DNA methylation is an epigenetic mechanism regulating gene activity without changing the DNA sequence. Most commonly, a methyl group is added to the 5-carbon of cytosine within 5′-CpG-3′ dinucleotides, forming 5-methylcytosine (5mC). It contributes to transcriptional regulation, cellular differentiation, genomic stability, development, genomic imprinting and cell identity. 🔹 CpG islands are GC- and CpG-rich regions, often near gene promoters. Many promoter-associated CpG islands remain unmethylated when genes are active, whereas aberrant promoter methylation can contribute to transcriptional repression through altered regulatory-factor binding and recruitment of chromatin-remodelling proteins. Importantly, methylation is context-dependent: its effects vary across promoters, enhancers, gene bodies and repetitive elements. 🔹 DNMTs are the pr...

WEEKEND READS 📚

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Recommended book of the weekend: 🍃 ☕ ➡️ "NEXUS" By Yuval Noah Harari   🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁🍁

HUMAN GENOME PROJECT, PANGENOME, AND GENOME ARCHITECTURE 🎗

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"The genome is the software of life." - J. Craig Venter 🧬 The Human Genome Project (HGP) was one of the most transformative achievements in modern biology. Launched in 1990 and completed in 2003, this international collaboration produced the first human reference genome (3.2 billion base pairs), transforming biomedical research. It accelerated next-generation sequencing, bioinformatics, precision medicine, and our understanding of inherited diseases, cancer, infectious diseases, and human evolution.      🔹 Despite its success, the HGP had important limitations. The original reference genome was derived from a limited number of individuals and could not fully represent global human genetic diversity. Highly repetitive regions, structural variants, centromeres, telomeres, and population-specific sequences remained incomplete. In 2022, the Telomere-to-Telomere (T2T) Consortium generated the first essentially complete human genome, demonstrating that a single li...