Down Syndrome: From Pregnancy through Childhood in Türkiye.

Introduction: Down syndrome is the most common genetic cause of multiple congenital malformations and intellectual disability. The prevalence of the disorder and accompanying malformations, prenatal and postnatal features, and clinical approach to the syndrome vary across different regions worldwide. This study aims to share our clinic's experience with Down syndrome from pregnancy through childhood from a medical geneticist's perspective and to summarize the prenatal and postnatal characteristics of our patients. Methods: A 10-year review of medical records was conducted for patients with Down syndrome who were followed between 2010 and 2021. Patient data including sex, karyotype, follow-up period, age at first and last visit, congenital malformations, organic disorders, prenatal screening data, neonatal history, neuromotor developmental milestones, and growth parameters were evaluated. Results: Overall, 324 children with Down syndrome were evaluated. Overall, 95% (308) had regular trisomy 21. The mean age at admission was 6.09 ± 1.99 months, and patients were followed for an average of 32.7 ± 3.97 months. Overall, 51% of neonates and 53.5% overall were hospitalized. While common disorders such as congenital heart defects (57.5%), neonatal hyperbilirubinemia (19.7%), and hypothyroidism (39%) were observed, rare conditions such as polydactyly, Ebstein anomaly, epilepsy, epileptic encephalopathy, nephrolithiasis, and cholelithiasis were also reported. Conclusion: The clinical features of Down syndrome observed in Türkiye have been summarized through our cohort. Medical teams need comprehensive knowledge about Down syndrome management. Childhood is recognized as a critical period in Down syndrome care, particularly regarding early diagnosis and treatment of congenital malformations and management of developmental delays.