Genetic Disorders

Genetics Disorders

Autosomal Recessive Disorder

Cystic Fibrosis

Autosomal recessive disorder that encodes for a protein called Cystic fibrosis conductance regulator which causes an ion imbalance in the body

Symptoms: excessive salty sweat, sticky mucus, digestion problems, respiratory problems

Health problems associated with CF include:

-Sticky mucous can cause infection

-Excessive loss of NaCl (through sweat)

-Pancreatic + intestinal issues resulting in digestion problems

Treatment:

-Enzymatic Digestive aids

-Nasal spray (DNAase)

-Antibiotics to combat possible respiratory bacterial infections

Probability of CF contraction:

1/25 individuals are heterozygous carriers

1/25 x 1/25 x 1/4 = 1/2500

Sickle-cell anemia

Autosomal recessive disorder that results in deformed hemoglobin-substitution of glutamic acid by valine

Ramifications:

-Shortened lifespan of red blood cell which results in anemia (not enough red blood cells)

-Oddly shaped cells clump resulting in poor circulation=impaired tissue and organ function, susceptibility to infection etc.

The body tries to compensate for the anemic conditions by generating more red blood cells but this results in deterioration of bone marrow

Pleiotrophy

Sickle cell anemia is an example of pleiotrophy 1 genotype results in more than 1 phenotype

Benefits of Sickle-Cell anemia

-Increased resistance to malaria

Therefore heterozygous individuals contain some benefits against malaraia but produce normal erythrocytes, example of heterozygous advantage

Phenylketonuria (PKU)

Decrease in the enzyme phenylalanine hydroxylase causes permanent mental retardation through inability to digest phenylalanine

Treatment: a diet that is absent of any phenyalanine will result in a normal child-example of how environmental alteration can sometimes modify phenotype