1. Genetics of Parenthood Quiz
What was the genotype of each of the parents for each trait?
How likely is it for any two sets of parents to each have a child that is the same for 2 traits? 3 traits?
How realistic is it that all of the parents would be genetically identical?
What hair type did each parent have?
What skin color?

2. Human Genetic Disorders
There are no cures
For these disorders
Because they are in the genes.

3. Recessive Disorders Most common type
Allele ‘hides’ in the heterozygous carrier
Both parents must be carriers for an individual to get these disorders
Examples – Cystic Fibrosis, Sickle Cell Anemia, PKU, and Tay-Sach’s

4. Cystic Fibrosis Autosomal recessive
Missing a transport protein in the cell membrane
Symptons - Thick Mucus clogs lungs, and other organs
Treatment – drugs and devices that loosen and remove mucus…vibrate chest and suction out mucus

5. Sickle Cell Anemia Autosomal Recessive,
Hemoglobin molecule has one different amino acid causing it to sickle when oxygen levels are low
Symptons include
Low energy, pain
Organ damage
Treatment – red blood cell transfusions

6. PKU - Phenylketonuria Autosomal Recessive
Individuals lack the enzyme to breakdown excess phenylalanine
Symptoms – Mental Retardation
Treatment –a diet very low in phenylalanine
All Babies in US are tested for this at birth

7. Tay-Sachs Autosomal Recessive
Babies are missing the enzyme to breakdown a lipid in the brain
Symptoms – After a period of normal growth, child regresses neurologically and dies
Treatment – none yet

8. Dominant Disorders
Rare because they usually make the person with even one allele unable to reproduce – (they die young)
Shows in heterozygous and homozygous individuals.
Examples include – Huntington’s disease and Dwarfism

9. Huntington’s Disease Autosomal Dominant
Something causes the nervous system to deteriorate (breakdown) The exact causes are not yet identified.
Symptoms – Occurs between 35
and 45 years old. Nerve function deteriorates resulting in death.
Treatment - none

10. Dwarfism Autosomal Dominant – All heterozygous
Caused by low amount of growth hormone
Symptoms – Short limbs and short stature
Treatment – Babies/children can be given growth hormone and grow to
normal height
Homozygous dominant
individuals die before birth

11. Sex-linked
On the X chromosome
Most commonly show in men

12. Hemophilia Sex-linked Lack the clotting factor
Symptoms – bleeding and bruising that doesn’t stop
Treatment – blood transfusions

13. Color Blindness Sex-linked
Lack the pigment in the eyes that distinguish between red and green
Symptoms – Can not tell some colors normally
Live with it – can’t be a pilot, or army chef

14. Chromosomal Disorders
When there is an abnormal number of chromosomes.
Caused by non-disjunction = the failure of chromosomes to separate normally during meiosis
Humans with disorders may have an extra and have 47 chromosome instead of 46.
They may also be missing a chromosome and have 45

15. Down Syndrome or Trisomy 21
Chromosomal
Have an extra chromosome 21
Short stature, mental retardation, large tongue, upward slant of eyes, other health problems
Quality education
and care

16. XXY Chromosomal Nondisjunction resulting in an extra X
Males with learning difficulties, tall, fast growth, reduced hair, beard and testicular size, usually infertile
Testosterone treatments to increase normal sex characteristics

17. XO or Turner’s Syndrome
Chromosomal
Nondisjunction resulting missing an X or Y chromosome
Female, short stature, fail to mature sexually, or maybe normal, sterile
None

18. XXX or Trisomy X Chromosomal
Nondisjunction during gamete formation resulting 3 X chromosomes
None – normal female
None