GENETIC CAUSES OF DOWN SYNDROME AND EARLY DIAGNOSIS METHODS IN PEDIATRICS

Down syndrome trisomy 21 is one of the most common chromosomal abnormalities, caused by the presence of an extra copy of chromosome 21. This genetic condition results in characteristic physical features, developmental delays, and varying degrees of intellectual disability. The underlying causes of Down syndrome include nondisjunction, translocation, and mosaicism, which disrupt the normal chromosomal segregation process during gametogenesis or embryonic development. This article provides an in-depth review of the genetic mechanisms that lead to Down syndrome and explores modern methods of early diagnosis used in pediatric and prenatal care. It also highlights the epidemiology, risk factors, and socio-medical importance of early detection. Early diagnosis plays a critical role in preventing complications, guiding parental counseling, and ensuring timely interventions that enhance the child’s quality of life. Recent advances in genetics and molecular testing, including non-invasive prenatal testing NIPT and cytogenetic analyses, have significantly improved the accuracy and accessibility of early detection. Ultimately, integrating genetic understanding with pediatric practice not only helps in reducing diagnostic delays but also strengthens multidisciplinary approaches in managing children with Down syndrome.