Genetic Diseases. Genetic diseases occur when an individual s DNA has one or more abnormalities.

Size: px

Start display at page:

Download "Genetic Diseases. Genetic diseases occur when an individual s DNA has one or more abnormalities."

Lora Hudson
6 years ago
Views:

1 Genetic Diseases Genetic diseases occur when an individual s DNA has one or more abnormalities. Autosomal dominant genetic disorders refer to diseases in which only one copy, the dominant allele, is needed to express the disease. Autosomal recessive genetic disorders refer to diseases in which two copies, both recessive, are needed to express the disease. Variants on these forms refer to the sex-linked dominant and recessive disorders. Even rarer are Y-linked disorders only males can ever express these disorders.

2 Huntington s Disease Autosomal dominant disorder in which symptoms do not appear until the individual is past the age of 30. Until then, the individual shows no signs of the disease unless he or she is genetically tested. Caused by a dominant gene which codes for a protein that gradually damages cells in the brain. This results in, over time, jerky movements and loss of control. Eventually cognitive abilities (i.e. brain function) becomes impaired due to the damage. No cure for this disease. Treatments can only prolong an individuals life span.

3 Marfan s Syndrome Autosomal dominant disorder of which the most serious symptoms are mitral valve prolapse (heart valve is reversed) and aortic aneurysm (bursting of the aorta). It is possible for individuals with Marfan s Syndrome to live normal lives. Caused by a dominant gene which codes for an incorrect protein for elastic fibers. Surgery can correct the mitral valve prolapse. But generally no cure, just treatment for symptoms.

4 Sickle-Cell Disease Autosomal recessive genetic disorder. An individual needs both recessive alleles in order to express this disease. Causes red blood cells to lose their elasticity and prevents their ability to squeeze through narrow blood vessels such as your capillaries. Treatments include blood transfusions and, rarely, complete bone marrow transplant to replace the bone marrow with tissue that are able to produce normal cells.

5 Cystic Fibrosis Autosomal recessive genetic disorder. Caused when a mutation prevents water and chlorine ions from traveling through a protein in the cell membrane. Main symptoms involve an inability to clear mucus from the lungs, which results in inflammation and the possibility of bacterial infection. Cystic Fibrosis also causes thickened secretions from the pancreas, which can cause damage and result in diabetic symptoms. No cure for Cystic Fibrosis. Treatments include chest physiotherapy (a therapist physically pushes the chest up and down to loosen the mucus), inhalants to loosen the secretions in the lungs, and long-term antibiotics to treat infection.

6 Cystic Fibrosis

Tay-Sachs Disease Autosomal recessive genetic disorder. Causes a steady deterioration of nerve cells due to gangliosides (cell membrane marker molecules) damaging the nerve cells of the brain.

7 Tay-Sachs Disease Autosomal recessive genetic disorder. Causes a steady deterioration of nerve cells due to gangliosides (cell membrane marker molecules) damaging the nerve cells of the brain. Those with Tay-Sachs disease lack the enzyme needed to break down these gangliosides. Major sign/symptom is a red spot on the retina of the eye. Infants who express symptoms of Tay- Sachs disease rarely survive past toddlerhood. No cure nor treatment.

8 Fragile X Syndrome Sex-linked dominant disorder. Causes a wide range of intellectual disabilities and psychosocial issues such as severe social anxiety, panic attacks, and ADHD. Suspected to be the cause of autism symptoms of individuals who have the fragile X chromosome. Females are less affected by the symptoms than males. (Why?) Physical characteristics can include large, protruding ears, elongated face.

9 Hemophilia Sex-linked recessive disorder. Rare in females. Results in the diminished, if not overall, lack of production of blood clotting factors. Symptoms include prolonged bleeding and bruising. Treatment includes the introduction of clotting factors into an individual s blood stream. However, treatment is usually given on demand as the treatment is expensive.

10 Hemophilia

11 Karotypes Karotypes are used to view the chromosomes of an organism. All organisms have a specific number of chromosomes, although this number is not unique for each organism (for example, dolphins and rabbits have the same number of chromosomes). For example: Adders Tonge Fern = 1260 chromosomes Pigeons = 80 chromosomes Donkeys = 62 chromosomes Dolphins = 44 chromosomes Rabbits = 44 chromosomes Yeast = 32 chromosomes Koala = 16 chromosomes Fruit Fly = 8 chromosomes

12 Down s Syndrome Karotype 3 chromosomes on pair #21 results in Down s Syndrome

13 Down s Syndrome Results in the following: -Impairment of physical and mental development and growth -IQ of children with Down s Syndrome is ~50, compared to ~100 for a normal child -Interventions and support at an early age can help mitigate intellectual and physical limitations

14 Patau s Syndrome Karotype 3 chromosomes on pair #13 results in Patau s Syndrome

15 Patau s Syndrome Results in major limitations in physical development to the nervous system, bones, muscles, kidneys, etc. Unusual for an individual to be born with Patau s syndrome Occurs in about 1 in 21,000 births

16 Turner s Syndrome Karotype A missing sex chromosome results in Turner s syndrome

Turner s Syndrome Individuals with Turner s Syndrome develop as females due to the missing sex chromosome Turner s Syndrome causes the individual to be

17 Turner s Syndrome Individuals with Turner s Syndrome develop as females due to the missing sex chromosome Turner s Syndrome causes the individual to be shorter than normal, as well as usually being infertile A second major concern for these individuals is the incidence of cardiovascular problems over time

18 Klienfelter s Syndrome Karotype An extra sex chromosome results in Kleinfelter s syndrome

19 Kleinfelter s Syndrome Individuals with Klienfelter s Syndrome develop as males due to the presence of the Y chromosome. Results in males having high concentrations of certain female hormones as well as underdeveloped reproductive organs A second major concern for these individuals is the high probability of osteoporosis and breast cancer

20 Edward s Syndrome Karotype An extra chromosome on pair #18 results in Edward s syndrome

Edward s Syndrome One year survival rate of individuals with Edward s Syndrome is 5-10% Picture at the right shows the physical characteristics of those born with Edward s

21 Edward s Syndrome One year survival rate of individuals with Edward s Syndrome is 5-10% Picture at the right shows the physical characteristics of those born with Edward s Syndrome These individuals also have numerous neurological limitations, cardiovascular problems, and malformations in major organ systems (like the digestive and pulmonary systems)

22 XYY Syndrome

23 XYY Syndrome Occurs when a male has a second Y chromosome on chromosome #23. Those with XYY Syndrome have normal phenotypes. There is still debate whether or not the additional Y chromosome leads to any developmental delays or behavioral problems.

24 Trisomy X

25 Trisomy X Occurs when a female has an extra X chromosome on chromosome #23. Usually, individuals affected by trisomy X are only taller than average and have no major phenotype differences. Like XYY Syndrome, individuals may experience developmental delays.

Friday, January 4. Bell Work:

Friday, January 4. Bell Work: Friday, January 4 Bell Work: Red green colorblindness is an X linked trait and is recessive. A male who is normal marries a woman who is a carrier, what is the phenotypic ratio of their offspring? 1 Genetic