Genetics of Heart disease Flashcards
Describe the two types of mutations
Monogenic - One gene mutation leads to disease
In the coding area
Polygenic - Many genes add up to increase risk
Not in the coding area
Give examples of Polygenic mutation/diseases
Hypertension, T2 diabetes, obesity
Define the Central Dogma
DNA is transcribed to RNA
RNA is translated to proteins
State 4 different bases
Adenine
Cytosine
Guanine
Thymine
Define what a chromosome is
DNA is packaged in chromosomes - the nucleic acid wrapped in structural proteins
Resides in the nucleus of the cell
Define what the human genome is
23 pairs of chromosomes, 2 sex chromosomes X and Y, and 22 pairs of non-sex chromosomes
Define coding DNA
Contains genetic information that is transcribed into RNA and that RNA is translated into protein - 1% of the human genome
Define a Gene
Region of DNA that is transcribed as a single unit and carries information for a discrete hereditary characteristic – RNA
Define a phenotype
Effects of DNA, RNA combined with environmental factors
The observable characteristics of an individual resulting of its genotype with the environment - ie hair colour, diseases
Describe the scale of mutations
Small scale - DNA sequences variants
Large scale - Chromosomal structure
State the other name for common DNA sequence variants
Polymorphisms
State some examples of Polymorphisms
SNP,VNTR, CNV and indel
Define a Single Nucleotide Polymorphism (SNP)
A polymorphisms where a single base differs from usual
Define Variable Number Tandem Repeats (VNTR)
A polymorphism where the number of repeats of short DNA sequences vary.
Varies between individual
Define Copy Number Variation
A polymorphism where the number of a larger pair (greater than 1,000 bases) varies
Define Indel
A polymorphism where a DNA sequences is present or absent
Describe the two different origins of DNA sequence variants
Germaline Transmission - mutation occurred in egg or sperm cell; can be passed on
Somatic Transmission - mutation occurred in a different cell; can’t be passed on
Define the difference between coding and non coding variants
Coding variants - easier to predict due to their genetic code being known and the translation into a protein sequence
Give an example of a classical genetic trait
Blood type
Define Mendel’s law of segregation
A person with two alleles will ‘segregate’ the two so there is a 50% chance of transmitting either
Define Mendel’s Law of Dominance
Heterozygote - allele which masks the other is referred to as dominant and the masked as recessive
Define Mendel’s law of independent assortment
Separate genes for separate traits are passed independently of one another parent to offspring
Define Autosomal
Gene is located in one of the non sex chromosomes
Define Autosomal Dominant
A single copy of the diseases-associated mutation is enough to cause the disease
Define Autosomal Recessive
Two copies of an abnormal gene is required to be present for the trait to develop
Define X-linked
Inheritance refers to genetic conditions associated with mutations in genes on the X chromosome
Define X-linked dominant
Single copy of the disease-associated mutation is enough to cause the disease
Define X-linked recessive
Two copies of an abnormal gene must be present for the disease or trait to develop
State what genetic testing is and does
Identifies DNA variants in affected individuals and estimates the probability that the variant is the cause of the disease
Describe the benefits what genetic testing can give
Identifies at risk individuals before onset of illness
fosters an understanding of pathogenesis and evolution
Promotes treatment strategies to interrupt disease progression and development
