1. Genetic Disorder
By: Nicholas Chan
D Core

2. Fabry disease
Fabry disease is a genetic disease passed on from parents to children. It is a disorder caused by lack of enzyme (chemical substances formed by living things, which will change other chemical substances if it didn’t change it self) needed to metabolize lipids, or fat. The excess buildup of a particular type of fat in the body’s cells leads to problems that affect many parts of the body. If the gene that controls the enzyme is mutated, then the lipids will break down which will then have harmful effects on the eye level, kidneys, autonomic nervous system and cardiovascular system. This disease occurs during childhood. The child will begin by having hot sensations in the hand which will get worse when the child is exercising and in hot weather. Then small raised reddish-purple marks will appear on the skin. The lipids will go to the heart and be stored there which will lead to a heart attack or a stroke. The heart maybe enlarged and the kidneys may become more progressively involved. Other symptoms may occur such as reduced sweating, fever and gastrointestinal difficulties after a meal. This disease is X recessive which means it affects males more than it does females since the gene affected by Fabry disease is the X chromosome. Males have only one X while females have a second X and therefore have some enzyme activity even though one of the X chromosomes is affected by Fabry disease.

3. X-Reccesive
X recessive is a weak X chromosome, which is inherited by a male or a female. The chances of a male having this disease if either of his parents have the disease or carries it is higher than a female. The female contains 2 “X” chromosomes while the male has only one X chromosome, this shows that the women has less likely to show the affected symptoms since it has a dominant X. But if the male gets the mutated recessive “Xr” then he will be affected by it, this is because it has only one X chromosome. Therefore there is a higher percentage that he will have the symptoms and be affected by it. It is also likely to be shown because the male only has one chance to be normal, this is necessarily a hemizygous. Because of this inheritance pattern, it is impossible for the male to be a carrier. But even though the female has one X recessive while the other X chromosome is unaffected, it doesn't mean that the symptom cannot be shown from the homozygous female. Also, it is rare for a women to have the symptoms/disease expressed in a phenotype( symptoms shown physically) (because of this pattern). And the female has 2 chances since it has two X chromosomes, so a female has a higher chance of not being affected by the Disease than the male.

4. Fabry Disease Punnett Square’s
Genotype: XX/XY: XXr: XrXr/XrY
Phenotype: 3:1 Sick:not sick/carriers
X = Dominant
Xr = Recessive (Disease)
Female X Xr
In this situation,2 child’s are not affected by the disease.
1 “XXr” is a carrier (female) and 1 has the disease (male)
Parents: Male: Not affected, Female: Carrier. X
XXr XX
Male XY
XrY Y
Female X X
If the mother is not a carrier nor affected by the disease while the father is affected by the disease, the 2 males will be affected by the disease, while the 2 females are fine.
Female X X
Male Xr
XXr
XXr X XX XX
Male Y XY XY Y XY XY
If both parents are fine, not having the disease, or carriers of the disease, all of the children will be fine.
Genotype:XX/XY: XXr: XrY/XrXr
Phenotype: 4:0 Carrier/normal: Sick
Genotype:XX/XY: XXr: XrY/XrXr
Phenotype: 4:0 Not sick: Sick

5. Female X Xr Xr XrXr Male XXr Female Y XY Xr Y Xr Xr X XXr XXr Male Xr
Genotype: XX/XY: XXr: XrY/XrXr
Phenotype:2:2 Sick:not sick, carriers Xr
If the Mother is a carrier, and the father is having the disease, 1 female is a carrier, 1 female is affected by the disease, 1 male isn't affected by the disease nor a carrier, and 1 boy has affected by the disease. Xr
XrXr
Male
XXr
Female Y XY
Xr Y Xr Xr
Female X
XXr
XXr
Male Xr Xr
If both parents have a disease, all of the children will be having the disease. (in this case) Y
XrY
XrY
Male Xr
XrXr
XrXr
In this case when the mother is having a homozygous recessive gene and marries a homozygous dominant male, the 2 males will have the disease while the 2 females will be carriers of the disease. Y
XrY
Xr Y
Genotype:XX/XY: XXr: XrY/XrXr
Phenotype: 4:0 Sick:not sick
Genotype:XX/XY: XXr: XrY/XrXr
Phenotype:2:2 Carriers:Sick

6. Bibliography http://en.wikipedia.org/wiki/X-linked_recessive

7. End of Genetic and Heredity