Down Syndrome
by Zeba Un Naher
1. Clinical manifestations
1.1. Low nasal bridge
1.2. protruding tongue
1.3. Flat & low-set ears
1.4. Epicanthal folds
1.5. Mental challenges
1.6. Poor muscle tone
2. Treatment
2.1. Regular medical checkups can help the child stay in good health condition
2.2. Watch for any early signs of health problems and seek for support
2.3. Help the child develop by providing social skills and emotional supports
2.4. Involve special educators, occupational & physical therapist
2.5. Depends on each child's medical needs and supports
3. Diagnostic tests
3.1. Screening tests
3.1.1. Ultrasound
3.1.2. Blood test- during 1st or 2nd trimester
3.2. Chorionic Villus Sampling
3.3. Aminocentesis
3.4. Cell-free fetal DNA analysis
3.5. Physical exam and baby blood test after birth
4. Genetic variations
4.1. Autosomal aneuploidy
4.1.1. Presence of Trisomy of Chromosome 21 (XXX)
4.1.1.1. Occurs in 97% of the cases
4.1.1.2. Results in each cell has an extra copy in Chromosome 21
4.1.2. Mosaic
4.1.2.1. Occurs only about 1% of the cases
4.1.2.2. presence of an extra copy in chromosome 21 in some of body's cells
4.1.3. Translocation
4.1.3.1. occurs in 3%to 5% of the cases
4.1.3.2. Occurs when a copy of chromosome 21 fuses to another chromosome during interchanging of genetic material
4.1.3.2.1. the interchanging of genetic material between nonhomologus chromosomes
4.1.3.2.2. involves the fusion of the long arms chromosomes 21 and 14, which causes an extra copy of the long arm of chromosome 21