B2 - Genetic Factors that Affect Development Flashcards
Key terms/introduction
Genetic predisposition = Inherited genes that determine physical growth, development, health and appearance.
Susceptibility = An increased likelihood of acquiring a disease because of an individual is genetic make-up.
Congenital = Present at birth.
Neural tube defects = Congenital defects of the brain, spine or spinal-cord.
Each living cell in the human body has a nucleus containing 23 pairs of chromosomes. In each pair of chromosomes, one comes from the father and one comes from the mother. Each chromosome carries units of inheritance known as genes, and these genes interact to create a new set of instructions for making a new person. Genes, for example, determine the colour of your eyes and hair and whether you’ll be short or tall.
Genes are made of a substance called deoxyribonucleic acid (DNA). Do you know contains the instructions for producing proteins. It is these proteins that regulate the development of human being.
Genetic predispositions to particular conditions
A predisposition is the possibility that you will develop a certain condition. A genetic predisposition means that you inherit that possibility from one/both of your biological parents. However, a genetic predisposition does not mean that it is a certainty that you will develop the condition. Although the genetic make up that predisposes these conditions cannot be altered, we can sometimes alter environmental factors and offer support and treatment to allow that individuals to develop and lead life as healthily as possible. There are some inherited conditions, some rarer than others, that have serious consequences for a child’s growth and development:
Cystic fibrosis
Cystic fibrosis is caused by a faulty gene thought to be carried by as many as 4% of the UK population. The gene is recessive, which means that both parents must be carriers for the child to develop cystic fibrosis. When both parents carry the faulty gene, there is a one in four chance that the child will be born with cystic fibrosis. Cystic fibrosis resulted in a defective protein being produced that can cause the lungs to become clogged with thick sticky mucus. People with cystic fibrosis may have problems absorbing nourishment from food and they may also suffer from respiratory and chest infections. In the past, children have cystic fibrosis often had a very short life expectancy, but contemporary medical treatments have succeeded in extending both the quality of life and life expectancy. Physiotherapy helps people with cystic fibrosis to clear mucus from the alarms. Various drugs help control breathing and throat and lung infections, and a special diet and drugs help with food absorption. In the future, it may become possible to use genetic therapy to replace a faulty gene.
Brittle bone disease
Brittle bone disease may be passed from a persons parents, but it can also develop from a genetic mutation. Children born with brittle bone disease are at a high risk of fracturing/breaking my bones easily because the bones develop without the right amount or type of protein called collagen. There are different types of the disease and sometimes more serious than others. Children have brittle bone disease can often be helped through physiotherapy, assistive equipment and drug treatments to help strengthen their bones.
Phenylketonuria (PKU)
PKU is a rare genetic disorder that prevent the child from breaking down phenylalanine, and 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. The condition cannot be cured. All babies in the UK are screened at birth by a heel-prick blood test. It’s a high funny Lala and then to level is detected, treatment will be started immediately with a special diet and medication to rent the buildup of hob. Senses. 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.
Huntington’s disease
Huntington’s disease can develop at any age but often starts between the ages of 35 and 55. Huntington’s disease is an inherited neurodegenerative genetic disorder that causes progressive damage to certain love cells in the brain. It can affect muscle coordination and cause mental decline and behavioural changes. The brain damage gets progressively worse over time, with perception, awareness, thinking I’m judgement (cognition) affected. Although the symptoms of the disease can vary between individuals, and even affected members of the same family, the progress of the disease is usually predictable.
The earliest signs are hardly noticeable and maybe missed or mistaken for other conditions, for example subtle changes in personality and mood swings, irritability, altered behaviour and fidgety movements.As the disease progresses, the features of the disease can include psychiatric problems, problems associated with feeding, communication and erratic behaviour. 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.
Klinefelter syndrome
Klinefelter syndrome is not easy to identify and small children as the signs and symptoms are not always obvious. It is estimated that around one and 600 boys will be born with this condition, sometimes referred to as XXY. The extra X-chromosome is acquired after the baby was conceived; it is not an inherited condition. Some of the signs include the baby 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 may also be signs. Many boys with this condition also experience difficulty socialising and expressing their feelings which can impact on emotional development and lead to low self-confidence.
Some boys with this condition experience mild learning difficulties such as low attention span and difficulty with literacy skills, especially reading, writing and spelling. They also experience higher rates of dyslexia or dyspraxia. Other physical signs include low energy levels and extra growth spurts (particularly in the legs and widening of the hips). The onset of puberty is often not affected. However, the tested do not increase in size and there may be a lack of testosterone leading to a flabby body, low muscle tome, a reduction in calcium in the bones, small firm testicles, a small penis and a lack of body/facial hair. There may be difficulties with sex drive (libido) and fertility. Treatment is available for load test Austrian levels. Most adult males with this syndrome or able to live independently and establish the careers and relationships.
Down’s syndrome
Down syndrome is a genetic condition that occurs as a result of an extra chromosome. The condition can cause varying levels of learning disability, the characteristic physical features and associated medical issues. Each year, approximately 750 babies born in the UK will have Down’s syndrome and recent research estimates at 60,000 people in the UK have the condition.
In the vast majority of cases, Down’s syndrome is not inherited. It is simply the result of a one-off genetic ‘mistake’ in the sperm or egg. There is a high risk of giving birth to a baby with Down’s syndrome for woman 45 years and older (about one and 50). In comparison, a 20-year-old woman has a risk of one in 1500.
The life expectancy of people who have down syndrome is generally between 50 and 60 years but with improvements in health care a small number of people with the condition live into their 70s.
According to research by NHS Scotland, people with down syndrome experience a higher incidence of depression. Other health conditions that are more common or hearing, visual or heart problems. Improved health and social care support and education has provided opportunities for young people who have Down’s syndrome to leave home and live independently so that they are able to form new relationships and going employment.
Colour blindness
True colour blindness is a very rare condition in which an individual has no colour perception at all. Colour vision deficiency, where individuals have difficulty in distinguishing between different colours, is commonly known as colourblindness. It affects approximately 2.7 million people in Britain, about 4% of the population, mostly men. The condition can vary in severity and some people do not realise that they are colourblind, leading a healthy life without treatment.
For the majority of people, the condition is genetic. Inherited colour vision deficiency is a result of an abnormality in the retina. Others will experience the condition as a result of other diseases such as diabetes and Multiple Sclerosis. The ageing process/side-effects of certain types of medication can also affect colour recognition.
Although it is important to identify any colour blindness of young children so that the learning experience is not affected, for most people the condition does not lead to long-term health problems. It is important that health and social care providers take colour blindness into consideration when delivering services are using appropriate colour schemes when producing printed information.
Duchenne muscular dystrophy
Muscular dystrophy is are a group of inherited genetic conditions that gradually we can muscles leading to disability. It is a progressive condition and worsens over time. Muscular dystrophy is caused by changes in the genes responsible for the structure and functioning of the persons muscles. This causes changes in the muscle fibres that interfere with their ability to function. The most common and severe form of the muscular dystrophy is is Duchenne muscular dystrophy. This condition is inherited on the female gene and is passed only to male offspring.
According to research on muscular dystrophy UK, about one in 3500 boys in the UK are born in fission muscular dystrophy. There are about 2500 boys living with the condition in the UK at any one time.
Do some muscular dystrophy is caused by genetic mutations on the X chromosome. This prevents the body from producing a vital muscle protein, dystrophin, which is essential for building and repairing muscles. The muscular weakness is not noticeable bath but becomes more noticeable in early childhood and more prominent as the child grows older.
The condition is usually diagnosed by the age of five and, by the time individuals 12, they may have to use a wheelchair. It is a serious condition with muscle weakness mainly in muscles made to the trunk of the body, around the hips and the shoulders. This means that fine motor skills such as using hands and fingers, the less affected than gross motor skills. Many young men with this and muscular dystrophy so severe health problems, especially by their late teens, as the muscles of the heart and long as we can.
Although the condition is severely disabling, many young men and muscular dystrophy are able to lead active lives. So I will be on the age of 30 was rare, but research and medical advances are increasing this and life expectancy is beginning to improve. The right specialist health and social care can make a huge difference to both the quality and length of life.
Susceptibility to disease
According to the world health organisation, most diseases involve environmental factors and the complex interaction of many genes. In other words, although an individual may not be born with the disease, their genetic make-up my make them susceptible to acquiring it later in life. Diseases and disorders that are more likely to happen in individuals with a susceptibility include:
Cancer
There are over 200 types of cancer. Cancer is a cell disease that results in them becoming abnormal and dividing to make even more of normal cells. Most cancers are activated to environmental and lifestyle factors. For example, lung cancer is closely linked with tobacco use and skin cancer to over exposure to ultraviolet light. It is estimated that over 40% of cancers can be prevented by making different lifestyle choices such as diet, not smoking, reducing alcohol intake, exercising and avoiding environmental factors such as exposure to the Sun or asbestos dust. Some people are more at risk because they have inherited gene faults that increase their risk. There are a number of cancers where are genetic link has been shown, including cancer of the breast, bowel, womb and kidney. For those with the faulty gene, getting cancer is not inevitable although an unhealthy lifestyle will increase the risk.
Diabetes
Diabetes is an increasingly common chronic condition affecting millions of people in the UK. Approximately one and 16 people in the UK have diabetes and this figure has doubled since 1996. Although other factors, such as environment and lifestyle are more likely to play a role in Type 2 (later/mature onset) diabetes, there is a strong predisposition to developing both Type 1 (early onset, insulin dependent open) and Type 2 diabetes. The genetic risk of developing Type 1 diabetes is higher if either/both biological parents have diabetes. The risk for developing Type 2 diabetes is almost 90% if you have an identical twin who is diabetic.
High blood cholesterol Lifestyle factors (such as unhealthy diet, smoking or lack of exercise) increases the chance of having a high blood cholesterol level for most people. Cholesterol is a fatty substance that is carried around the body by proteins. Too much can cause a build-up in the artery walls. This can cause heart disease and other cardiovascular diseases. Another reason for high cholesterol levels is an inherited condition that runs in families, known as familial hypercholesterolaemia. In the UK, approximately one and 600 people have this condition. It is caused by a gene alteration inherited from a parent. People with this type of high blood cholesterol are born with a condition and can lead to early heart problems unless treated. There is a 50% chance that a child/sibling of someone diagnosed with familial hypercholesterolaemia will also have the condition.
Biological factors that affect development
The environment inside of mothers womb can have a dramatic influence on the Childs development. If a woman smokes or drinks alcohol during pregnancy, fetal development may be affected. The nicotine inhaled into smoking contains carbon dioxide which gets into the bloodstream restricting the amount of oxygen to the fetus. Children born to mothers who smoke tend to weigh less at birth and are more prone to infections and twice as likely to die of cot death.It can affect the Childs long-term development including their attention span and learning disabilities. Taking drugs and getting some types of infection can also damage the Childs development in the womb. Some examples of biological factors that affect development include:
Fetal alcohol syndrome
Drinking alcohol during pregnancy carries a huge risk to a babies health and development. Mothers may give birth to children of Fito alcohol syndrome. Children with this condition have developmental physical defects which have life-long effects. They tend to be smaller and to have small ahead to the normal caused by poor brain development. These children may also have heart defects, learning difficulties and neurological problems.
Return of infections during pregnancy
If a pregnant woman is exposed to, or acquired infections such as rubella (a type of measles) or cytomegalovirus (a heroes-type virus) the foetus May be adversely affected. Repeller is particularly dangerous during the first month of pregnancy. If a mother becomes infected in this period her baby may be born with impaired hearing or eyesight, or damaged heart. Most women are vaccinated against Rabeler to prevent this risk. Cytomegalovirus is a common virus belonging to the herpes family. It spreads via bodily fluids. Most people are infected with CMV at some stage of their life but the majority have no noticeable symptoms. If a pregnant woman has an in an active infection they can pass it to the fetus are this is referred to as congenital CMV. Around 1 or 2 babies in 200 are born with congenital CMV and around 13% of those are born with symptoms such as definites and learning difficulties and 14% or develop problems later on.
Lifestyle/diet during pregnancy
Our biological life starts at conception, approximately nine months before we were born. Babies are affected by what the mothers eat during pregnancy and breastfeeding. Some recent animal research suggest that if a pregnant/breastfeeding woman has a diet high in sugar and fat it can result in an increased risk of high blood cholesterol and lead to heart disease for the child. Malnutrition/a lack of healthy food during pregnancy may result in a lifetime of poor health for the child. The food standards agency recommends that pregnant women should eat plenty of fresh fruit and vegetables, plenty of starchy foods such as bread and pasta and rice, foods rich in protein such as lean meat, chicken and fish, plenty of fibre and foods containing calcium such as milk and cheese. They also advise that woman should avoid/limit alcohol and avoid too much caffeine, which may result in a low birth weight.
Congenital defects
Congenital defects are the most common cause of childhood: illness, disability and death. About nine in every 1000 children in the UK are born with congenital defects. The most common and severe congenital defects are heart defect, neural tube defects and Down’s syndrome.
Congenital defects may be genetic but other factors can also be responsible, for example:
~ Socio-economic factors especially lack of access to sufficient nutritious food during pregnancy.
~ Environmental factors such as working/living in polluted areas, exposure to chemicals/pesticides, excessive use of tobacco, alcohol and drugs during pregnancy.
~ Infectious diseases (during pregnancy) such as syphilis and rubella.
Sometimes it can be difficult to identify a specific cause.
Some congenital defects can be prevented by adequate antenatal care including screening, vaccination and adequate intake of nutrients such as minerals and vitamins, especially folic acid.
