1. Human Genetics

2. Fugate Family Father + 4 children are blue

3. Luna Fugate and John Stacey

4. In Hazard, the County Seat

5. What makes them blue? Methemoglobinemia
Red blood cells (RBC) from blue people are deficient in NADH diaphorase activity and cannot reduce the oxidized iron in methemoglobin (metHb).

6. Symptoms
Blue colored skin
Headaches
Fatigue
Coma
Death

7. Degree of Blueness
RBC from the parents of blue people (obligate heterozygotes for the blue trait - Bb) do contain some NADH diaphorase activity but not as much as homozygotes (BB) for the normal allele.

8. Treatment The homozygous patient (bb)
daily ingestion of ascorbic acid to increase non- enzymatic reduction of methemoglobin
or the use of methylene blue.

9. Pedigrees
A chart that shows the relationships within a family and how a trait is passed from one generation to the next

11. Language
Generation: all of the people born and living at about the same time, regarded collectively; average span of time between the birth of parents and that of their offspring.
Phenotype: Disease vs. Non-disease
Shaded= Have disease (DOES NOT TELL GENOTYPE)
Non-Shaded= Do not have disease (phenotype, does not tell genotype)
Heterozygotes
In recessive disease traits: Carriers for disease trait (do not have, but can pass to offspring
In dominant disease traits: have disease

12. Pedigree Example Generations

13. Albinism – no pigment in skin, hair and eyes
Human Genes Recessive Disorders: Affected must be homozygous recessive.
Albinism – no pigment in skin, hair and eyes
Shaun

14. PKU – accumulation of phenylalanine in tissues
PKU – accumulation of phenylalanine in tissues. Mental abnormalities, abnormal skin pigments PKU
Tay-Sachs – lipid accumulation in brain cells. Early death Gavin

15. Dominant Disorders: affected individuals only need 1 dominant allele
Huntington Disease: People start to show symptoms in their thirties or forties. It causes gradual damage to the nervous system.
HD?

16. Achondroplasia – dwarfism
Carys and Gary

17. Genes that cause Molecular Change
Cystic Fibrosis (CF)
accumulation of mucus in lungs
Lauren's Story

18. Sickle Cell Anemia
CODOMINANT: caused by a change in the shape of red blood cells.
RBC can not travel efficiently throughout the capillaries.
Stop blood movement through these vessels; damage cells and tissues.
Life With Sickle Cell - YouTube

19. 1 every 500 African American
The allele for normal hemoglobin (HA) is codominant to the sickle cell allele (HS)

20. More common on African descendent people (10% of African American, and as many as 40% of African).
Why is this trait so common on those particular populations?
People who are carriers for sickle cell are resistant to malaria – better chance of survival!

21. Practice Pedigrees
Video – sickle cell (from VCU) Bg

22. Blue Pedigree of Fugates
= male with it
= female with it

24. Can you work out the genotypes?
Pedigree of Fugates
Can you work out the genotypes?

25. Pedigree with Genotypes
trait visible
carrier

27. Recessive Disorder Pedigree Cystic Fibrosis
Individual must have two recessive (small letters) alleles in order for trait to be expressed (disease phenotype)
If an individual is HETEROZYGOUS (one big, one little), they do NOT have the disease, BUT THEY CAN PASS THEIR LITTLE ALLELE ON TO THEIR OFFSPRING
Heterozygotes are CARRIERS for the disease.

28. Cystic Fibrosis Pedigree

30. Dominant Disorder Pedigree Huntington’s
A dominant allele causes the disease.
Only need ONE disease allele to cause the disease, SO:
INHERITANCE PATTERN IS DIFFERENT THAN RECESSIVE DISEASE TRAITS
THE DISORDER IS USUALLY SEEN MORE OFTEN FROM GENERATION TO GENERATION
THERE ARE NO CARRIERS, if a person has ONE allele, then the have the disease (phenotype)

31. Huntington’s Pedigree