Albinism A Genetic Disorder Gabby and Stef A. Period 6/7

About Albinism Albinism is a disorder that affects the skin, hair, and eyes. The hair, eyes, and skin usually have no pigment(color). Symptoms: No color in hair, skin, or iris of the eyes. Lighter hair color and skin. Patch, or missing skin color. Interesting Facts: Sometimes the eye color can change People with albinism are sensitive to light (photophobic) Other forms of Albinism are involved with symptoms of other disease

Albinism’s Chromosome OCA1 is located in Chromosome 11 . Chromosome 11 Location of OCA1 on Chromosome 11

Albinism is Autosomal Recessive Mode Of Inheritance Albinism is Autosomal Recessive Autosomal Recessive- Two copies of the abnormal gene must be present in order for the disease or trait to develop.

Alleles Allele- Alternative forms of a gene for each variation of a trait of an organism. One from mother, One from Father. Recessive- aa -Trait that can be masked by the dominant form of a trait. Dominant- AA Observed trait that masks the recessive form of a trait.

Punnett Squares A a a a AA Aa aa Aa A A a A

Punnett Squares and Ratios AA Aa aa Ratios- 1 2 1 AA | Aa | aa A a Percentages- 25% 50% 25% AA | Aa | aa

AA aa Aa A a Punnett Squares A a A = Dominant Allele a = Recessive Allele AA Aa aa A Genotype: In Gene AA = Homozygous Dominant(not albino) Aa = Heterozygous dominant(not albino) aa = Homozygous recessive(albino) a Phenotype: AA= Not albino Aa = Not Albino but Gene Carrier aa= No Melanin/Albino

AA aa Aa A a Punnett Squares A a Phenotype- Physical (Seen) Ratios: 1 Albino ; 3 Not Albino Percentages: 25% Albino ; 75% Not Albino AA Aa aa A a Genotype- Genes (Genetic) Ratios: 1AA : 2Aa : 1aa Percentages: 25%AA: 50%Aa: 25%aa

Aa aa Aa aa a a Student Practice! A a Genotype: Ratio: 1 : 1 : 2 Percentage: 25% : 25% : 50% Phenotype: Ratio: 2 NO Albinism; 2 Albinism Percentage: 50% Albinism ; 50% No Albinism Aa aa a Aa aa a

Pedigree Gabby Tyler Jessica Kevin Steph Ventura Yvenson Stef Emma Jeff Purple- Fine. NO ALBINISM! Pink- Not fine. ALBINISM PRESENT!

Student Practice Gabby Tyler Jessica Kevin Ventura Steph Yvenson Stef Key Circle: Female Square: Male Pink: Albinism Purple: Non-Albinism Gabby Tyler Jessica Kevin Ventura Steph Yvenson Stef Emma Jeff Questions: What will happen to the child if both of the parents have recessive genes? What would the result be if Emma and another recessive male had children? Would the child have albinism or not?

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