📌 Definition
Down Syndrome is a genetic disorder caused by the presence of an extra (third) copy of chromosome 21 (trisomy 21), leading to intellectual disability, characteristic facial features, and multiple congenital anomalies.
🧠 Anatomy & Physiology
- Genetics: Trisomy 21 results from nondisjunction, translocation, or mosaicism.
- Systemic involvement: Affects cognitive development, musculoskeletal system, cardiac, gastrointestinal, and immune systems.
- Intellectual disability: Typically mild to moderate, with delayed milestones.
⚠️ Etiology: Causes & Risk Factors
- Maternal age: Increased risk with advancing maternal age (>35 years).
- Genetic factors: Parental balanced translocation (rare).
- Previous child with Down Syndrome increases recurrence risk.
🩺 Symptomatology
- Facial features: Flat facial profile, epicanthal folds, upward slanting palpebral fissures, small nose, protruding tongue, low-set ears.
- Musculoskeletal: Hypotonia (floppy baby), joint hyperflexibility, short stature, single palmar crease (simian crease), short broad hands.
- Congenital anomalies: Congenital heart defects (AV septal defect, VSD, ASD), GI anomalies (duodenal atresia, Hirschsprung disease).
- Other: Intellectual disability, developmental delay, increased risk for leukemia, hypothyroidism, recurrent infections, early-onset Alzheimer’s disease.
🔁 General Pathophysiology (Simplified)
- Non-disjunction or other chromosomal error leads to three copies of chromosome 21.
- Overexpression of genes affects multiple organ systems.
- Leads to characteristic physical, cognitive, and medical findings of Down Syndrome.
🧪 Medical Management
🔬 Labs & Diagnostics
- Prenatal screening: Maternal serum screening, nuchal translucency, cell-free DNA testing.
- Postnatal diagnosis: Karyotyping (confirms trisomy 21).
- Screen for congenital heart defects (echocardiogram), thyroid function tests, hearing and vision screening.
💊 Medications/Treatment
- No cure; management is supportive and multidisciplinary.
- Treat comorbidities (heart surgery for CHD, thyroid hormone for hypothyroidism).
- Early intervention programs: Physical, occupational, and speech therapy.
- Monitor and treat infections promptly.
🧑⚕️ Nursing Management: 5 Key Interventions
- Provide early intervention and developmental therapies for optimal growth and independence.
- Monitor for and manage associated health issues (cardiac, thyroid, GI, hearing, vision).
- Educate parents/caregivers on developmental expectations, health maintenance, and community resources.
- Promote infection prevention and routine immunizations.
- Support family coping and encourage inclusion/social participation.
🩹 Possible Priority Nursing Diagnoses
- Delayed growth and development related to chromosomal abnormality.
- Risk for infection related to altered immune response and comorbidities.
- Imbalanced nutrition: Less than body requirements related to feeding difficulties.
