Upgrade to remove ads
MMG - 16
Terms in this set (35)
An allele is one of two or more forms of the DNA sequence of a particular gene.
Allelic Heterogeneity (Definition)
Different mutations in the same gene cause a disease.
Allelic Homogeneity (Definition)
Specific mutations associated with the same disease such that every affected individual carries exactly the same molecular defect.
Locus Heterogeneity (Definition)
Mutations in different genes can cause the same disease.
Locus Homogeneity (Definition)
Many diseases caused by different mutations in the same gene.
Phenotypic Heterogeneity (Definition)
Different mutations in the same gene give rise to completely different disorders.
Phenotypic Heterogeneity (Example)
Different mutations in the β-globin gene which cause different forms of anemia is an example of this genetic phenomenon.
Locus Homogeneity (Example)
Both DMD and BMD are caused by mutations in the same gene, which is an example of this type of genetic phenomenon.
Locus Heterogeneity (Example)
Mutations in 9 different genes can cause Xeroderma pigmentosum, which makes it an example of this type of genetic phenomenon.
Allelic Heterogeneity (Example)
Different patients with the same disease are found to have different mutations in the same gene is an example of this genetic phenomenon.
The diverse effects of a single gene on multiple organ systems and functions.
Mutations in the same gene causing defects/problems in a wide range of tissues is an example of this genetic phenomenon.
Variable Expressivity (Definition)
Occurs when expression of a phenotype varies widely in severity, onset and systems affected, between individuals with the same specific genotype.
Variable Expressivity (Example)
If two individuals with the same genotype display different levels of mental retardation.
This occurs when an allele of one gene can mask the phenotypic expression of alleles of another.
Fetal hemoglobin production masking the insufficiency of a sickle cell patient's blood is an example of this genetic phenomenon.
The proportion of individuals with a mutation who exhibit clinical symptoms.
This is said to exist if every patient with the same mutation displays the disease to which it is linked.
This is the most common allele that causes cystic fibrosis, which comprises 70% of the affected population.
The second most common allele that causes cystic fibrosis, which comprises 2.4% of the affected population.
Congenital bilateral absence of the vas deferens - causes infertility in males.
Compound heterozygosis (Definition)
When a different disease allele is found on one of each homolog.
Compound heterozygosis (Example)
A patient with ΔF508 on one homolog, and G524X on the other homolog is said to have this kind of genotype.
Poly T Tract - CF (Definition)
A string of thymidine bases in intron 8 of the CFTR Gene which can be associated with CFTR-related disorders depending on its size. Variants of this region affect CFTR mRNA levels.
Cystic Fibrosis Transmembrane conductance Regulator gene. Defects in this gene cause cystic fibrosis.
Most common variants of the Poly T Tract
5T, 7T, 9T
This variant in the poly T tract results in low levels of expression and a near absence of protein resulting in the corresponding phenotype of the allele.
This variant in the poly T tract results in moderate levels of expression and moderate phenotype due to intermittent splicing anomalies.
This variant in the poly T tract results in full expression and normal protein levels resulting in the corresponding phenotype of the allele.
Incomplete Penetrance (Definition)
The phenomenon in which the frequency of expressino of a phenotype is less than 100%, that is not everyone with a disease genotype displays the corresponding phenotype.
Incomplete Penetrance (Example)
The risk of breast cancer by age 70 in women with BRCA1 mutations is 85% is an example of this genetic phenomenon.
Complete Penetrance (Definition)
A patient with a specific mutation will display the specific phenotype associated with it.
Complete Penetrance (Example)
Every patient with a mutation in the FGFR3 gene will have achondroplasia.
Symptoms of a genetic disease do not manifest until much later in life.
More than 50% of gene activity is necessary for normal funciton.
THIS SET IS OFTEN IN FOLDERS WITH...
(First Aid) Embryology
USMLE - Biostats
Reproductive USMLE 1
MBM - Genetics
YOU MIGHT ALSO LIKE...
FA 2015 - Biochemistry: Genetics
DC Biology 201 Ch 11, 12, 13
OTHER SETS BY THIS CREATOR
Parasites and Bacterial Shapes
CSF - Immune Functions