Human Genetics

1. Human Genetics

2. Identifying Human Phenotypes:

12. PTC Taster

18. Examining Human Traits • Complicating factors Ambiguous phenotypes, multiple alleles, major and minor genes, turn off genes, penetrance, expressivity • Environment important factor

19. Pedigree – Family history to show the transfer of genetic traits Key Mating Male Affected male Offspring, in birth order (first-born on left) Female Affected female

20. Genetic disorders Pedigree : Chart used to trace family histories of genetic traits

21. Pedigree

23. Hemophilia Family Tree

25. Karyotyping

26. Karyotyping

27. Down’s Syndrome

29. Autosomal Dominant Traits

30. ACHOO Syndrome • Sneezing in bright light

31. X • Dwarfism – Homozygous lethal

32. Sickle Cell Anemia Blood disease – 99% Black population Codominant trait

33. PTC Taster Bitter chemical taste Phenylthiocarbamide

34. Polydactyly - extra finger or toe

35. Autosomal Recessive Traits

36. Albinism – (7 kinds in humans)

37. PKU Phenylketonuria Lack enzyme to metabolize phenylalanine. Mental retardation without treatment. N. European descent

38. PKU - 1 in 15,000 Americans. • A non-food source of phenylalanine is the artificial sweetener Aspartame. This compound, sold under the trade names "Equal" and "NutraSweet", is metabolized by the body into several chemical byproducts including phenylalanine.

42. Cystic Fibrosis Prevents normal breathing and digestion. White americans

43. Tay-Sachs Disease Nervous system deterioration. European Jews

44. Porphyria • Port wine urine disease • Iron abnormality • George III – American Independence, Mary Queen of Scots • Rare form – eastern Europe • Long fine hair all over body, dying necrotic tissue, eyes sensitive to light, gums destroyed, teeth with iron deposits

45. Porphyry ?

46. Sex-linked RecessiveColorblindness

47. Sex-linked Recessive Hemophilia