Quiz 3: Chromosomal disorders

Please choose the one, most correct answer to each question or statement.

1. What is Down syndrome?
   • A condition caused by insect bites and resulting in generalised oedema.
   • A common diagnosis in Mongolia (China).
   • A recognisable pattern of clinical features and malformations.
   • A syndrome diagnosed by examining the urine.
2. How common is Down syndrome at birth (birth prevalence) in South Africa?
   • 1 per 1000 live births.
   • 2 per 1000 live births.
   • 5 per 1000 live births.
   • 10 per 1000 live births.
3. In South Africa Down syndrome births are commoner:
   • In summer.
   • In winter.
   • In women younger than 35 years.
   • In women 35 years or older.
4. Why is the diagnosis of Down syndrome often missed in South Africa?
   • Because the diagnosis is difficult to make in children.
   • Due to a lack of awareness by parents and health-care workers.
   • Because most infants with Down syndrome die of infection during the first days of life.
   • Because most infants are born at home and do not attend clinics.
5. In Down syndrome there is extra material from which chromosome?
   • 15
   • 18
   • 21
   • 22
6. What is the most common cause of Down syndrome?
   • Trisomy.
   • Translocation.
   • Mosaicism.
   • A single gene defect.
7. What is a typical facial feature of Down syndrome?
   • Downward slanting eyes.
   • A big nose.
   • A large head.
   • A relatively large tongue.
8. The hands of children with Down syndrome:
   • Usually have an extra finger.
   • Usually have a single palmar crease.
   • Are long and thin.
   • Usually have very small nails.
9. The feet of infant with Down syndrome:
   • Often have one or two toes missing.
   • Often have club feet.
   • Often have a wide gap between the big and second toe.
   • Usually have long toes.
10. Infants with Down syndrome typically have:
    • Hypotonia (floppiness).
    • Increased tone.
    • A very good Moro reflex.
    • Convulsions.
11. What is the pattern of growth in children with Down syndrome during the first months of life?
    • Commonly obese.
    • Usually thin and wasted.
    • Slow growth.
    • Rapid growth.
12. When should the parents of an infant with Down syndrome be told the diagnosis?
    • It is best if they are left to find out for themselves.
    • As soon as possible.
    • When the child gets to school-going age.
    • When the child reaches puberty.
13. Children with Down syndrome often have:
    • Cerebral palsy with increased muscle tone.
    • Normal intelligence.
    • Visual problems.
    • Paralysis.
14. Children with Down syndrome are at an increased risk of:
    • Arthritis.
    • Anaemia.
    • Recurrent infection.
    • Bleeding.
15. What is a common complication of Down syndrome?
    • Congenital heart defects.
    • Congenital kidney failure.
    • Congenital diaphragmatic hernia.
    • Congenital deafness.
16. What is the life expectancy of individuals with Down syndrome in South Africa?
    • The same as people without Down syndrome.
    • More than half die before two years of age.
    • At least 25% die on the first day of life.
    • Most are stillborn.
17. How can children with Down syndrome be helped to reach their full potential?
    • They should be placed in a special institution as soon as they are one year old.
    • They should not be stimulated as this is too stressful for them.
    • They should be stimulated by their parents at home and receive early neurodevelopmental therapy.
    • Neurodevelopmental therapy should only be started when they are ready for school.
18. How can a pregnant woman be screened for a fetus with Down syndrome?
    • X-ray of the mother’s abdomen to look for duodenal atresia in the fetus.
    • Ultrasound examination at 12 weeks to look for increased skin thickness over the back of the fetal neck.
    • A blood test at 25 weeks of gestation
    • Measurement of symphysis-fundal height to look for abnormal fetal growth.
19. How can the diagnosis of Down syndrome be confirmed during pregnancy?
    • Chromosomal analysis on a sample of amniotic fluid.
    • Triple test on the mother’s blood at 20 weeks.
    • Ultrasound examination for ventricular septal defect (VSD).
    • Chorionic villous biopsy to determine whether the fetus has hypothyroidism.
20. What is the risk of a 25 year old woman having a second child with Down syndrome due to non-disjunction?
    • 1%.
    • 15%.
    • 25%.
    • 50%.