1. Chapter 7: Congenital and Genetic Disorders Pathophysiology Ms. Harris

2. Congenital/Genes Congenital= defects or damage to a developing fetus that are present at birth –Genetic abnormalities –Malformation –Chromosomal abnormalities Genes- are segments of DNA that code for a specific trait. DNA is what makes up chromosomes.

4. Chromosomes Humans have 23 pairs. (23 from egg, 23 from sperm that join together to form the zygote) Karyotypes show all pairs –1-22 = Autosomes –23 rd pair = sex chromosomes

5. Normal female Normal male

6. Chromosomal Disorders Can be diagnosed by identifying abnormalities on a karyotype. Failure of chromosomes to separate in meiosis = non-disjunction (result is either a monosomy or trisomy) Translocations, deletions of chromosomes can also occur

7. Can you spot the abnormality?

8. Trisomy 21 More commonly called Down Syndrome Causes mental retardation, shortened lifespan, oblique eye, smaller chin 1 in 1000 births

9. Can you spot the abnormality?

10. Turner’s syndrome Malfunctioning ovaries, sterility, heart defects, short stature 1 in 2500 female births

11. Can you spot the abnormality?

13. Congenital Defects, cont. Sometimes, just a single gene is affected. Sometimes, they are multifactorial

14. Congenital Disorders, cont. Can be inherited or caused by teratogenic agents –Things that cause damage to the fetus Smoke, alcohol, etc.

15. Punnett Squares Used to predict chances for having a child with one of the following types of disorders: –Autosomal dominant, autosomal recessive, sex-linked dominant, sex-linked recessive

16. Punnett Square Review 1.Autosomal recessive(ex. Cystic fibrosis) What are the chances that an affected female and a normal (homozygous) male will have a child with cystic fibrosis?

17. Punnett Square Practice Autosomal dominant (ex. Huntington’s) –What is the probability that and affected (heterozygous) parent and a normal parent will have a child born with Huntington’s disease?

18. Punnett Square Practice X- linked disorder (duchenne’s muscular dystrophy) –What is the probability that a carrier female and a normal male will have a child born with MD?

19. Pedigree Practice

20. Multifactorial Disorders Lots of things factor into the expression of the disease –Many genes –Environmental factors –Etc.

21. Developmental Disorders Anomalies can be caused by exposure to teratogens. –Mercury, alcohol, many chemicals –First 2 months are the most critical because cells are differentiating (organogenesis) –Cerebral Palsy

22. Diagnostic Tools Amniocentesis for prenatal diagnosis Neonatal blood testing following birth –Most hospitals make several tests mandatory

23. Gene therapy Current Event Analysis: 1.Name 3 cause/effects from the article. 2.Make a T-chart to list pros and cons of gene therapy. (think beyond the article!)