B2. Genetic Factors Flashcards
What is DNA?
t is a chemical made up of two long molecules, arranged in a spiral. We refer to this as the double-helix structure.
Where is DNA found?
It is found in your chromosomes
You have 23 pairs of chromosomes
Each chromosome has Genes, which is made up of a sequence of DNA
The Genes will determine your genetic makeup
What does DNA contain?
DNA contains the instructions for making proteins. These proteins regulate the development of a human being
What is a genetic predisposition?
A genetic predisposition is an increased likelihood of developing a particular disease based on a person’s genetic makeup.
Give some examples of Predisposition diseases?
Cystic Fibrosis Brittle bone disease Phenylketonuria (PKU) Huntington’s disease Kleinfelter Syndrome Down Syndrome Colour Blindness Duchenne muscular dystrophy
Give some examples of susceptible diseases?
Cancer
Diabetes
High blood cholesterol
Give some examples of biological factors?
Foetal alcohol syndrome Maternal infections during pregnancy Lifestyle choices during pregnancy Diet during pregnancy Congenital defects
Describe the CF gene
One in 25 people carry the CF gene. For someone to be born with CF, both parents must carry the faulty gene.
What is PKU?
PKU is a rare genetic disorder that prevents a child from breaking down phenylalanine, an amino acid (a building block for protein) found in many foods such as milk, meat and eggs. In PKU, if the child eats foods containing phenylalanine there is a build-up of harmful substances in the body that damages brain development.
Can PKU be cured?
The condition cannot be cured. All babies in the UK are screened at birth by a heel-prick blood test. If a high phenylalanine level is detected, treatment will be started immediately with a special diet and medication to prevent the build up of harmful substances.
How does PKU impact life?
A baby born with undetected PKU would fail to meet developmental milestones and experience developmental delay as their brain became damaged. Untreated PKU would result in severe learning disability and the child’s death.
How is brittle bone disease inherited?
Brittle bone disease may be passed from a person’s parents, but it can also develop
from a genetic mutation.
What is brittle bone disease?
a disorder causing fragile bones that break very easily
Children born with brittle bone disease are at high risk of fracturing or breaking their bones easily because their bones develop without the right amount or type of a protein called collagen.
can brittle bone disease be cured
It is a lifelong disorder
Children with brittle bone disease can
often be helped through physiotherapy, assistive equipment and drug treatments to
help strengthen their bones.
What is Huntington’s disease?
Huntington’s disease is an inherited neurodegenerative genetic disorder that causes progressive damage to certain nerve cells in the brain.
When does Huntington’s disease develop?
Huntington’s disease can develop at any age but often starts between the ages of 35 and 55.
How does Huntington’s disease affect life?
It can affect muscle coordination and cause mental decline and behavioural changes. The brain damage gets progressively worse over time, with perception, awareness, thinking and judgement (cognition) affected.
What are the earliest signs of Huntington’s disease?
The earliest signs are hardly noticeable and may be missed or mistaken for other conditions, for example subtle changes in personality and mood swings, irritability, altered behaviour and fidgety movements.
What happens as Huntington’s disease develops?
As the disease progresses, the features of the disease can include psychiatric problems, problems associated with feeding, communication and erratic behaviour.
What happens during the later stages of Huntington’s disease?
During the later stages of the disease, movement, behaviour and cognitive abilities are affected and the individual becomes increasingly dependent on other people for care and support.
What is Kleinfelter Syndrome?
A genetic condition in which a male is born with an extra X-chromosome.
How many boys will get Kleinfelter Syndrome?
It is estimated that around one in 600 boys will be born with this condition, sometimes referred to as XXY. The extra X chromosome is acquired after the baby is conceived
What are the signs of Kleinfelter Syndrome in babies?
the baby is slow in reaching milestones such as sitting up, crawling and walking.
The baby may be born with undescended testicles. Poor muscle power, delayed communication and a passive personality
What are the signs of Kleinfelter Syndrome in boys?
experience difficulty socialising and expressing their feelings which can impact on emotional development and lead to low self-confidence.
experience mild learning difficulties such as low attention span and difficulty with literacy skills, especially reading, writing and spelling
experience higher rates of dyslexia or dyspraxia
physical signs include low energy levels and extra growth spurts, particularly in the legs and widening of the hips
The testes do not increase in size and there may be a lack of testosterone leading to a flabby body, low muscle tone, a reduction in calcium in the bones, small firm testicles, a small penis and lack of body or facial hair
There may be difficulties with sex drive (libido) and fertility
