Flashcards in Week 1 GID Deck (62)
Is stroke genetic or enviromental cause or both.
multifactorial with environment and polygenic factors. Sometimes can be caused by a single gene influence (Cadasil)
The traits of a genetic disorder
Rare, Genetics simple, Unifactorial, High recurrence rate: high chance of others to have disorder
The traits of enviromental disorder
Common, Genetically complex, multifactorial, low recurrence rate,
What does multifatorial mean
The combination of multiple gene inheritance and the affect of the enviroment
What is single gene mutation
mutation in a single gene
imbalance or rearrangement in chromosome structure eg aneuploidy, deletion, translocation
mutation in mitochondrial DNA
Mutation that occur in the general genes and can cause cancer
Does AD inhertiance run between generation and does it affect males or females more?
runs between generations and affects males and females equally
% chance of inheritance of AD disease
50% chance of inhertiance for new born
Give examples of AD inhertiance disease
What does penetrance mean?
The frequency with which a specific genotype is expressed by those individuals that possess it, usually given as a percentage.
What is incomplete inheritance and give example of mutation of this type?
not all relatives who inherit the mutation develop the disorder – eg BRCA1 mutations 80% life time chance of developing breast cancer
What type of inheritance is AD
What does expressivity mean?
variation in expression - the extent to which a heritable trait is manifested by an individual. how the disease shows itself
What does Anticipation mean and give example
the symptoms of a genetic disorder become apparent at an earlier age as it is passed from one generation to the next. In most cases there is an increase in the severity of symptoms too. Example is Huntington’s disease
New mutation/ De novo
a new mutation that has occurred during gametogenesis or in early embryonic development. The parents do not have it
Is Ar disease passed on between generations and equal between genders
Usually only seen in one generation and equal in affect
Is Ar inheritance gene mutation or chromosomal deletion
What is the chance of inheriting a Ar disease
Risk of the unbrone child being a carrier of Ar diseae
Give examples of Ar diseases
• Cystic fibrosis
• Many of the metabolic disorders
• Sickle cell disease
In X linked disease is the male or female affected
Male are affected but females can be mildly affected ranging to severe symtpoms
Can or cant a male transmit the XL disease and why?
It cannot because males only give the Y chromsome and therefore only transmit from the female
give examples of XL diseases
o Duchenne Muscular dystrophy,
o Fragile X syndrome
o Red / green colour-blindness
What are the probablities for the child if the mother is a carrier
o 1/4 (25%) normal girl + 1/4 (25%) carrier girl
o 1/4 (25%) normal boy + 1/4 (25%) affected boy
Probablity if the father is affected
o All daughters are carriers
o All sons are unaffected (no male to male transmission
The two main factors that affect the expression of the phenotype of XL disease in females is
XL dominant vs XL recessive inheritance
Can you predict the phenotype of a female who havea XL disease with prenatal testing?