1. Genetic Disorders

2. Genetic Disorders Four types of genetic disorders
Single gene: disorders caused by the abnormality or mutation in the sequence of one gene
Multifactorial: caused by a combination of environmental factors and mutation in multiple genes
Chromosomal: Abnormalities in chromosomal structure such as missing chromosomes or extra copies
Mitochondrial: caused by a mutation in the non-chromosomal DNA of the mitochondria

3. Mutation
A mutation is any random change in the amount or structure of genetic material (DNA)
can be harmful, helpful, or have no impact
happen because of random changes during cell division (meiosis/mitosis)

4. Single Gene Mutation
A Gene Mutation is a change that affects a specific gene on a chromosome
the DNA sequence is altered, resulting in a different trait

5. Single Gene Mutation Sickle Cell Anemia
An abnormality of the hemoglobin (oxygen carrying protein in the blood) that leads to them being sickle-shaped
A sufferer of sickle cell carries two copies of the recessive sickle cell gene, located on chromosome 11
Health problems may include pain, swelling in hands and feet, or anemia (reduced red blood cells or ability to carry oxygen)
Affects 4.4 million people worldwide

6. Single Gene Mutation Cystic Fibrosis
An autosomal recessive disorder in which normally thin secretions such as sweat, digestive fluid, and mucus become thick
The disorder affects mostly the lungs but also the pancreas, liver, kidneys and intestine.
Long term issues include difficulty breathing and lung infections
About I in 25 people is a carrier while the disorder affects 1 in 3000

7. Single Gene Mutation Hemophilia
a mutation of a gene that causes a deficiency of a blood clotting protein resulting in abnormal bleeding
Sex-linked disorder with gene for hemophilia on the X chromosome
Affects 1 in people

8. Chromosomal Mutation
Genetic disorders may be passed down from parents (heredity) or they may be caused by new mutations or changes to the DNA
A change involving either part of, or all of, a chromosome
Caused by problems during meiosis such that gametes have abnormal chromosomes
This results in the offspring inheriting a change in genetic material and different traits

9. Chromosomal Mutation Nondisjunction
The addition or loss of a whole chromosomes
Errors in the segregation of chromosomes during meiosis resulting in the presence of an abnormal number of chromosomes in a cell
the leading known causes of miscarriage and the most frequent cause of developmental disabilities.

10. Chromosomal Mutation

11. Chromosomal Mutation
Down Syndrome: trisomy of the 21st chromosome (5.4 million world-wide)
Physical growth delays
Mild to moderate intellectual disabilities
Characteristic facial features

12. Chromosomal Mutation
Turner Syndrome: only one X 23rd chromosome resulting in a female with underdeveloped sexual characteristics (1 in )
Visual impairments and learning disabilities
Webbed neck, broad chest, and short stature
Underdeveloped ovaries resulting in infertility

13. Chromosomal Mutation
Klinefelter Syndrome: XXY 23rd chromosome resulting in a male with underdeveloped sexual characteristics (1 in )
Learning disabilities
Reduced strength, uncoordinated
Reduced fertility of infertile

14. Karyotyping
Karyotyping is a test to examine chromosomes in a sample of cells, which can help identify genetic problems as the cause of a disorder or disease in a developing baby. This test can:
Count the number of chromosomes in cells
Look for structural changes in chromosomes in cells
Use this as a diagnosis

16. Multifactorial
Genetic disorders may also be complex, multifactorial, or polygenic, meaning they are likely associated with the effects of multiple genes in combination with lifestyles and environmental factors
Multifactorial disorders include heart disease and diabetes
There is no clear cut pattern of inheritance due to the complexity of the disorders

17. Multifactorial Cancer
Mutagens, carcinogens, and particular viruses can cause mutations that lead to cancers because they change the internal and external factors that normally control cell division resulting in cancer
A mutated cancer cell grows and divides uncontrollably causing tumors to form
Tumors that don’t interfere with tissue function are benign (non-cancerous), while those that do interfere with tissue function are called malignant
Initial tumor cells can spread and form more malignant tumors in other tissues in the body

18. Multifactorial Carcinogens
Asbestos: Used as ceiling and pipe insulation in older buildings, floor tiles, and fire-resistant fabrics
Known to cause cancers of the lungs, digestive tract and the abdominal lining
Internal Combustion Engine Exhaust: gas emitted as a product of the combustion of fuels such as natural gas, gasoline, diesel, coal, etc.
Known to cause cancers of the lungs and bladder
Ultraviolet radiation: electromagnetic radiation present in sunlight (about 10% of sunlight is ultraviolet radiation)
While having beneficial effects (promotes production of vitamin D and serotonin), overexposure can damage DNA in the skin cells causing skin cancers melanoma and carcinoma