Clinical meaning
Trisomy 21, or Down syndrome, results from an extra copy of chromosome 21 due to nondisjunction during meiosis. This chromosomal abnormality leads to overexpression of genes on chromosome 21, affecting multiple organ systems. The extra genetic material disrupts normal development, causing characteristic physical features, intellectual disability, and increased risk of congenital heart defects. Down syndrome is the most common chromosomal cause of intellectual disability. The nurse assists with monitoring growth and development, supporting feeding, and reporting changes in respiratory or cardiac status.
Exam relevance
Risk factors: - Advanced maternal age (especially >35 years) - Previous child with trisomy 21 - Parental chromosomal translocation carrier status - Family history of chromosomal abnormalities
Diagnostics: - Monitor vital signs and report abnormalities - Measure and document head circumference, weight, and length at each visit - Observe feeding patterns and report difficulties - Monitor respiratory status and report increased work of breathing - Report signs of cardiac compromise: cyanosis, diaphoresis with feeding, poor weight gain