Genetic Disorders And Gene Therapy Flashcards
Why do mutations change the integrity of cells❓
What is the significance of this❓
1. Mutation in gene ⬇️ Change of codon ⬇️ Change of amino acid ⬇️ Change of conformation of protein ⬇️ Change of function of protein
- Genetic disorders result from genomic mutations
What is gene therapy❓
What is germ-line gene therapy❓
1.
•Correction of defective genes that are responsible for disease development
•Cures only affected cells
- •Permanent transfer of a gene into sperm or eggs to correct chromosomal or single gene diseases
•Cures future generations
- What are the approaches in gene therapy❓
- Which approach is the most common❓
- Which approach involves homologous recombination❓
- Which approach involves selective reverse mutation❓
1. •Insertion of normal gene to compensate for a nonfunctional gene •Abnormal gene is traded for normal gene •Abnormal gene repair •Change regulation of gene pairs
- Insertion of normal gene to compensate for a nonfunctional gene
- Abnormal gene is traded for normal gene
- Abnormal gene repair
Chromosomal diseases (abnormal chromosome numbers) are usually caused by nondisjunction in meiosis
True or false
True
Offsprings inherit extra chromosome or are missing a chromosome
What is Down’s syndrome❓
What are the characteristics of a child with Downs Syndrome❓
How can a confirmatory diagnoses be made❓
1.
•Chromosomal disease •Results from the presence of an extra (3) of chromosome #21 in each cell nuclei
2. •Wide, round face •Mental retardation •Enlarged tongue •Speech difficulty
- Karyotyping (visual display of chromosomes)
What happens in a single gene disease❓
There is:
- Correct number of chromosomes
- One chromosome contains gene responsible for the disease
What are alleles❓
What do they control❓
They can be dominant/recessive/codominant
True or false
Different forms (expressions) of genes
Traits
True
What is a genotype❓
What is a phenotype❓
1.
•Genotype refers to which alleles are found on the chromosomes
•eg WW, Ww, we
- •Phenotype refers to which expression is seen b/c of the allele
•eg Widows peak or straight line
What is Huntington’s disease❓
Is it caused by a dominant or recessive allele❓
Prevalence❓
1.
•Neuromuscular genetic disease
•Loss of psychomotor control
2.
Dominant allele
3.
1 in 10,000 people
*Asymptomatic till after 30yrs
What is Cystic fibrosis❓
Is it caused by a dominant or recessive allele❓
- •Disease of respiratory system
•Excessive production of mucus in the bronchi of the lungs
•Breathing difficulty - Recessive allele
What is Sickle Cell disease❓
Is it caused by a dominant or recessive allele❓
How come a person who has sickle cell trait is more resistant to malaria❓
Prevalence❓
1. •Irregularly-shaped Hb of RBC •Causes sickle shaped RBC •Circulatory problems •Anemia, pain
- None. Codominant
- Plasmodium cannot survive easily in a sickle cell RC
- ⬆️in ethnic groups in areas where malaria is a problem (African Americans)
What is Hemophilia❓
Is it caused by a dominant or recessive allele❓
Prevalence❓
- Disorder of impaired blood clotting
- X-linked, recessive
- 1 in 10,000 males
What is Adenosine Deaminase Deficiency❓
Is it caused by a dominant or recessive allele❓
- Severe immunodeficiency
- Autosomal recessive
No gene therapies have been approved by the FDA, but what are some gene therapy successes❓
Successfully treated:
1. Melanoma
- Severe combined immunodeficiency
- Hereditary blindness
- Sickle cell anemia
How is gene therapy done❓
Infect a viral vector with health gene ⬇️ Insert vector into the cell ⬇️ Vector inserts healthy gene into cell ⬇️ Activate the gene so transcription and translation takes place ⬇️ Functional proteins are created from healthy gene
