Down Syndrome (trisomy 21)

1. 1 in 800 live births

1.1. Prenatal Diagnosis

1.1.1. amniocentesis

1.1.2. chorionic villus sampling (CVS)

1.1.3. analysis of fetal DNA in maternal blood (recent years)

1.2. Karyotype shows:

1.3. 47 chromosomes

1.4. trisomy of chromes 21

2. Life Expectancy

2.1. 3/4 of fetuses are spontaneously aborted or stillborn, 20% of the infants die during first 10 years of life

2.1.1. rrrrrrrrrrrr

2.1.2. Joseph Conrad "Heart of Darkness"

2.2. If they survive beyond 10 years, average life expectancy is about 60 years

3. Risks of having a child with Down Syndrome

3.1. maternal age

3.1.1. 35-39 about 0.2%, 40- 45 about 1%, over 45 3-5%

3.2. family history

4. Associated medical conditions

4.1. Heart defects

4.1.1. Atrioventricular septal defect

4.2. reduce ability to fight respiratory tract infections

4.3. increased susceptibility to leukemia

4.4. mental and emotional problems

4.5. Alzheimer disease by age 40

5. Distinctive Characteristisc

5.1. mental retardation

5.1.1. IQ between 25-70

5.2. low nasal bridge,epicanthal folds, protruding tongue, flat, low set ears

5.3. poor muscle tone, short stature

5.4. congenital heart defects