Alzheimer's Disease

Kai LinChase Upshaw

January 27, 2010Period 09-10

Summary of Alzheimer's

• It’s a progressive disease of the brain.

• Mainly characterized by memory loss.

• It was first recognized in the early 1900s.

• Symptoms Personality changes Frequent and unexplained mood swings Difficulty/inability to do things they once where

able to do Temporary confusion while in normal

environment Difficulty finding words and keeping casual

conversation

Where is this disorder located?

Where does it come from?

• Alzheimer's is still not entirely explained.

• The risks of have Alzheimer's are 11% if neither parents have Alzheimer‘s 36% if one parent has it 54% if both parents have the disease 40%-50% if an identical twin has it

• 68% of those with Alzheimer‘s in the U.S. are women.

• 85% of those with Alzheimer‘s in the U.S. are white.

What Are Alleles?

• Alleles is another way of saying genes.

• Alleles come from your parents.

• There are dominant alleles, represented with a capital letter, and recessive alleles, represented with lowercase letters.

• EXAMPLE: WW, ww, Ww

• Dominant alleles have more influence than recessive alleles.

Punnett Squares

a a

A Aa Aa

a aa aa

A a

A AA Aa

A Aa Aa

a a

a aa aa

a aa aa

a a

A Aa Aa

A Aa Aa

Parent #1

Parent #2

Dominate Allele

Recessive alleleHomozygous Dominant

Heterozygous Dominant

Homozygous Recessive

Ratios and Percentages

Ratios

2 : 2

2 Aa : 2aa

Percentages

50% : 50%

50% Aa : 50% aa

A a

a Aa aa

a Aa aa

What do the letters in the Punnett Square mean?• AA or Aa- Dominant allele (Alzheimer’s)

• aa- Recessive allele (No Alzheimer’s)

• Phenotype (What you see)

AA- Alzheimer’s gene

Aa- Alzheimer's gene (carries the non-Alzheimer’s gene, but the Alzheimer’s gene dominates)

aa- Non-Alzheimer’s gene

• Genotype (What is in the genes)

AA- Homozygous Dominant (Alzheimer’s)

Aa- Heterozygous Dominant (Alzheimer’s)

aa- homozygous recessive (Non-Alzheimer’s)

Ratios and Percentages Cont.

• Phenotype

Ratio- 2 Alzheimer’s : 2 Non-Alzheimer’s

Percentage-

50% Alzheimer’s : 50% Non-Alzheimer’s

• Genotype

Ratio- 2 Aa : 2 aa

Percentage- 50% Aa : 50% aaA a

a Aa aa

a Aa aa

Student Practice

A a

AAA

a aa

Aa

Aa

• Genotype

Ratio1 AA : 2 Aa : 1aa

Percent25% AA : 50% Aa : 25% aa

• Phenotype

Ratio3 Alzheimer’s : 1 Non- Alzheimer’s

Percent75% Alzheimer’s : 25% Non-Alzheimer’s

Hypothetical Pedigree Chart

The white figures with the lines through them mean that the person died of something other than Alzheimer's Disease. The black figures with the lines through them mean that the person died of Alzheimer’s Disease. The black figures mean that the person has Alzheimer’s Disease while the white figures mean that the person does not have Alzheimer’s Disease.

More Student Practice

Circle- MaleSquare- FemaleHalf shaded in- Heterozygote DominantShaded in- Homozygote DominantNot shaded in- Homozygote Recessive

1. What is the percentage of people in the second generation that have Alzheimer’s Disease?

2. How many people have the recessive gene? Dominant gene?

3. How many people do you think will have the homozygote dominant gene? Why?