1. HUMAN GENETICS
Disorders

2. Interpreting Pedigrees with Andrew Douch
Interpreting Pedigrees the Fast Way –Example 1(6:42)
Example 2 (6:46)
1. Is anyone with a phenotype different from parents?
2.Are there any girls with recessive phenotype who have a father or son with a dominant phenotype?
Autosomal Dominant X-linked dominant
Autosomal Recessive X-linked recessive

3. Autosomal Dominant: trait does not skip generations

4. Autosomal Recessive: tends to skip generations

5. X-linked dominant: both males and females affected does not skip generations
Affected sons have an affected mother

6. X-linked recessive: more males than females affected
Skips generations: affected sons from non-affected mothers

7. Testing for genetic disorders
Ultrasound imaging-a sonogram made from passing high-frequency sound waves with a transducer through the abdomen
(least invasive)

8. Testing for genetic disorders
Amniocentesis-a small amount of amniotic fluid, which contains fetal tissues, is sampled
Use cells for karyotyping

9. Testing for genetic disorders
Chorionic villus sampling (CVS)-take a sample of the placental tissue for chromosomal abnormalities
Can use cells for karyotyping

10. AUTOSOMAL RECESSIVE
Autosomes = , chromosomes #1- #22

11. Cystic Fibrosis-ff On Chromosome 7 Autosomal recessive
It causes the body to produce a thick, sticky mucus that clogs the lungs and digestive tract.
On Chromosome 7
Autosomal recessive

12. One test is for salty skin CF salt test
Salty skin (Mutations of the CFTR gene affect functioning of the chloride ion channels)
thin (do not digest well)
abnormal bowel movements
CFTR video (8:18) describe 6 mutation disfunctions for 2 pts Ex Cr

13. Cystic Fibrosis (cont.)
Most common fatal genetic disease in US today
Most common in Caucasians
Small Child CR Treatment (thumping)
Thumping Vest (1:24)
Living with CF (3:48)
Daily meds

14. Cystic Fibrosis Chromosome 7 FF = no CF Ff = carrier ff = has CF
(recessive)
Life with CF (3:48)

15. Phenylketonuria (PKU)

16. PKU on chromosome 12 recessive
Lacks enzyme to break down the amino acid phenylalanine (found in milk)

17. PKU (cont.)
The breakdown products can be harmful to developing nervous systems
Leads to mental retardation.
Kate with PKU Movie

18. PKU
Chromosome 12
Put on low protein diet
Avoid phenylalanine

19. TAY SACHS Highest rate in Eastern European Jews, next Irish-Americans
Results in degeneration of the nervous system.
Chromosome 15
recessive
Highest rate in Eastern European Jews, next Irish-Americans

20. Tay Sachs (cont)
Lack enzyme to break down fat, accumulates in brain (poisons it) tt
Chromosome 15
NOVA Online | Cracking the Code of Life | Watch the Program Here #3

21. Tay Sachs Disease is a fatal lipid storage disorder where a fatty substance (ganglioside) builds up in the nerve tissue and cells of the brain. This is caused by an insufficient enzyme called beta-hexosaminidase A that catalyzes the biodegration of gangliosides.

22. Tay-Sachs Symptoms
Symptoms first appear at 4 to 6 months of age when an apparently healthy baby gradually stops smiling, crawling or turning over, loses its ability to grasp or reach out, and eventually
becomes blind, paralyzed and unaware of its surroundings. Death usually occurs by age 4.
Tay-Sachs PT (1:52)

23. Albinism Inability to manufacture pigments (melanin) in skin and eyes
Autosomal recessive trait
Chromosome 11

24. Albinism

25. Famous Albinos Andy Warhol, a famous artist
“The Twins” in Matrix Reloaded
Rock musician Edgar Winter, an albino.

26. Is this an advantage or disadvantage?

27. Different kinds of albinism
affect chromosomes 1, 9, 10, 11, 15 and X (ocular albinism)
Often rapid back and forth eye movement – lack of pigment in eyes.

28. Polar bears actually have black skin under all that white fur.

29. AUTOSOMAL DOMINANT on chromosomes 1-22

30. Sickle Cell Anemia Autosomal dominant disease Chromosome #11
Red blood cells collapse and clot blood vessels
Found in African-Americans

31. Sickle-Cells Normal Red Blood Cells-like a donut
Sickle-cells collapse, hard, clog vessels

32. Sickle-Cell Anemia Codominant SS = disease
AS = carrier (somewhat resistant to malaria)
AA =normal hemoglobin
Living with SSA
Plasmodium in blood - malaria

33. Sickle-Cell Complications
1.pain episodes
2.strokes
3.increased infections
4.leg ulcers
5.bone damage
6.yellow eyes or jaundice
7.early gallstones
8.lung blockage
9.kidney damage and loss of body water in urine
10.painful erections in men (priapism)
11.blood blockage in the spleen or liver (sequestration)
12.eye damage
13.low red blood cell counts (anemia)
14.delayed growth

34. Huntington’s Disease Woody Guthrie’s disease (folksinger 1960’s)
Autosomal dominant
Does not manifest itself until age 20’s - 30’s
H=dominant disease

35. What is the chance of a child of a Huntington Mother having Hungtingtons?

36. Huntington’s 40+ CAG’s (build up protein clumps) Chromosome 4
Atrophy of brain
Uncontrollable muscle spasms
40+ CAG’s (build up protein clumps)
Huntington's Chorea Dance (5:33)
Controls thinking, emotion, movement

37. Huntington’s Clumsiness Jaw clenching Loss of coordination and balance
Slurred speech
Swallowing and/or eating difficulty
Uncontrolled continual muscular contractions
Walking difficulty, stumbling
Hostility/irritability Inability to take pleasure in life
Lack of energy
person with Huntington's also may exhibit psychotic behavior:
Delusion
Halluciations
Inappropriate behavior (e.g., unprovoked aggression)
Paranoia

38. Achondroplasia -Autosomal Dominant -chromosome 4
Achondroplasia: Genetic Causes (2:40)

39. Achondroplasia Dwarfism
Average adult male height of 52 inches; average adult female height of 49 inches
Dwarfism
Achondroplasia: Genetics (2:20)
short stature
shortening of limbs,
trident hands
prominent forehead

41. FAQ
Can short-statured couples become the parents of average-size children?
AA=dead
Aa=Achondroplasia
aa=normal
A a A a

42. FAQ
Can short-statured couples become the parents of average-size children?
AA=dead
Aa=Achondroplasia
aa=normal
A a AA Aa aa A a X

43. Alzheimer syndrome
Widespread nerve cell dysfunction and cell death in the brain
Dementia (memory loss)
Alzheimer's Disease: Medical Update (1:39)
Life with Alzheimers
(3:56)

44. Alzheimer Syndrome Autosomal Dominant
Found on Chromosome 1, or 10, or 14, or 19, or 21
APO4, is a cholesterol-carrying protein linked to development a protein that forms plaque in the brain
Alzheimer's neurology (1:01)
Alzheimers' Disease: Neurology

45. Brain Loss

46. Early or mild stage: memory loss, especially of recent events
difficulty in recalling names and conversations
misplacing objects 
becoming lost in familiar neighborhoods
repeating stories and conversations
difficulty in learning new information
personality changes
decreased motivation and drive
easily upset or anxious 

47. Marfan Syndrome
autosomal dominant disorder
chromosome 15

48. Marfan’s: taller, pigeon chest Marfan's Video (2:45)
Spidery fingers, enlargement of aorta

49. Michael Phelps Does Not Have MarfansX
Extra Tall Athletes in their recruiting physical are tested for Marfans.
Clarence Holloway of Louisville does have Marfan's syndrome (had open-heart surgery)
Manute Bol did
Died at age 47
Gheorge Muresan
7’7”

50. Marfan Syndrome a connective tissue disorder
Affects skeleton, lungs, eyes, heart and blood vessels.
unusually long limbs
High arch palate
Debated if Abraham Lincoln has Marfan’s.

51. SEX-LINKED DISORDERS
On X chromosome

52. Hemophilia- “bleeder’s disease” New Hemophilia Treatment (48 secs)
Living with Hemophilia (4:53)

53. Hemophilia blood tainted with AIDS
60 Minutes:Hemophiliacs Sue the Blood Donors Organizations

54. Hemophilia passed by queen victoria
Blood does not clot normally
Sex-linked recessive
Missing AHF (clotting factor in blood)
Czar Nicholas royal family

55. Royal Pedigree-Hemophilia

56. “bleeder’s disease” XHXh = female carrier XHY = normal male
XhXh = female hemo
XHY = normal male
XhY = hemo male

57. Color Blindness More common in males Sex-linked (red and Green) on
inability to perceive differences between some of the colors that others can distinguish.
More common in males
Sex-linked (red and
Green) on
X chromosome
What it's like being color-blind? (3:35)

58. Color Blindness 3 seconds to determine number
Ishihara Test for Color Blindness

59. Ishihara Test for Color Blindness
The individual with normal color vision will see a 5 revealed in the dot pattern. An individual with Red/Green (the most common) color blindness will see a 2 revealed in the dots.
Are You color blind? (2:26)
Ishihara Test for Color Blindness

60. Color blindness=can’t tell certain colors
Recessive on X chromosome = c
XCXc = normal female (carrier)
XcY = color-blind male

61. What numbers do you see?

62. Note: X and Y used

63. Need X and Y on Punnetts

64. Duchenne Muscular Dystrophy

65. MD Duchenne Muscular Dystrophy On Xm chromosome
Weakens and degenerates muscles
Found mostly in males
mutation in the dystrophin gene

66. DMD
absence of dystrophin, a protein that helps keep muscle cells intact.
-Leg muscles first.
-Calves often enlarged.
-Eventually this weakness spreads to the arms, neck, and other areas.

67. DMD Onset ·Early childhood - about 2 to 6 years.
Symptoms · Generalized weakness of muscle
Wasting affecting limb and trunk
Duchenne Timeline (5:43)

68. DMD Survival rare beyond late twenties.
X-linked recessive (females are carriers).

69. Determination of disorder occurs on more than one chromosome
POLYGENIC DISORDERS
Determination of disorder occurs on more than one chromosome

70. SPINA BIFIDA is a fault in the spinal column in which one or
more vertebrae (the bones which form the backbone) fail to form properly, leaving a gap or split.
A Snapshot of Spina Bifida (4:52) 

71. Spina Bifida #6, #14 and others
Gap in spinal column

72. Shunts often put in the brain to drain the fluid

73. Agent Orange
Children with Spina Bifida whose parent was in contact with Agent Orange during the Vietnam War are compensated

74. Cleft Lip/Cleft Palate
#11, #17, #22
A cleft is an opening in the lip, the roof of the mouth (hard palate) or the soft tissue in the back of the mouth (soft palate).

75. Clefts
Bilateral Complete Cleft Lip/Palate
Clefts occur more often among Asians and certain groups of American Indians
than among whites.
They occur less frequently
among blacks.

76. Cleft lip/palate As you can imagine there are feeding problems
#11, #22, #17 –
Polygenic
Unilateral Cleft Lip Repair (9:15)

78. Hypercholesterolemia polygenic dominant
is the presence of high levels of cholesterol in the blood.
lead to atherosclerosis (hardening of the arteries)
additive effects of multiple genes (polygenic)
yellowish patches consisting of cholesterol deposits above the eyelids.

79. Hypercholesterolemia

80. On Y chromosome SRY gene: male determining only on Y
Testes determining factor

82. If you are born with no “X” chromosome- it is fatal
NOTE:
If you are born with no “X” chromosome- it is fatal
If missing an autosome-it is fatal

83. X chromosome
Sex-linked traits

84. Triple-X Syndrome triplo-X trisomy X XXX syndrome 47,XXX aneuploidy
There is usually no distinguishable
difference to the naked eye
between women with triple X
and the rest of the female population.

85. Triple-X Syndrome
Although females with this condition may be taller than average, this chromosomal change typically causes no unusual physical features.
Most females with triple X syndrome have normal sexual development and are able to conceive children.

86. Nondisjunction Chromosomes to segregate unevenly during meiosis
Mistakes in Meiosis

87. Down’s Syndrome Trisomy 21 Extra fold over eye Sluggish muscles
Mental problems

88. Trisomy 21 Karyotype

89. Nondisjunction

90. Turner’s Syndrome
Adults with Turner syndrome are short, averaging around four feet, eight inches in height.
Flap in neck
Small breasts

91. But girls with Turner syndrome don't start life as very short individuals - they become short over time-do not develop sexually

92. Turner’s Syndrome 45 X0

93. Kleinfelter’s 47 XXY

94. Kleinfelter’s -Testes are small -breast growth (gynaecomastia)
-poorly developed secondary sexual characteristics.

95. Men are sterile (no sperm).
Klinefelter’s
Men are sterile (no sperm).

96. Special Topics In Human Genetics

97. BARR BODIES So there is not excess of X info in females
When a female is born one of her X chromosomes is inactivated = a Barr Body (early in embryonic development)
Used to test femaledness at Olympics
So there is not excess of X info in females

98. Calico Cat – X linked
Only females have 3 colors (orange, black, white)
Looks like “Pepper”

99. Multiple colors in cats mostly in females

100. GENETIC DISORDERS REFERENCE SHEET: Down Syndrome (Trisomy 21) Edward's Syndrome (Trisomy 18) Patau Syndrome (Trisomy 13) Klinefelter Syndrome (47, XXY)
Turner Syndrome (45 XO)
Metafemale (46XXX)-taller
Autosomes (#1-22) so 44 if normal

101. Angelman Syndrome Deletion of Chromosome 15 If inherited from FATHER
Symptoms: Short and obese, delayed development, frequent laughing

102. Angelman Syndrome

103. Prader-Willi Syndrome
Deletion is inherited from mother’s chromosome 15
Hyperactive, chronic hunger, low muscle tone, obesity

104. Prader-Willi Syndrome
Before and after controlled eating