1. Unit 1 Human Lifespan Development
B – Factors affecting human growth and development

2. B2 – Genetic factors that affect development
Genetic predispositions to particular conditions – cystic fibrosis, brittle bone disease, phenylketonuria (PKU), Huntington’s disease, Klinefelter’s syndrome, Down’s syndrome, colour blindness, Duchenne muscular dystrophy, susceptibility to disease such as cancer, high blood cholesterol and diabetes
Biological factors that affect development – foetal alcohol syndrome, effects of maternal infections and lifestyle/diet during pregnancy, congenital defects.

3. Genetic Predisposition to particular conditions
Genetic Predisposition = the possibility that you will develop a certain condition, based on inherited genes you inherit from your parents, that determine physical growth, development, health and appearance
Although genetic make-up that predisposes these conditions cannot be altered, you can sometimes alter environmental factors and offer support and treatment to allow the individuals to develop and lead life as healthy as possible.
Some inherited conditions that have serious consequences for a child’s growth and development.

4. Cause of Cystic Fibrosis
a faulty recessive gene (thought to be carried by 4% of the UK)
It results in a defective protein being produced that can cause the lungs to become clogged with thick sticky mucus.

5. Symptoms of Cystic Fibrosis
Problems absorbing nourishment from food
Respiratory problems
Chest infections

6. Care / Treatment for Cystic Fibrosis
Physiotherapy helps to clear mucus from their lungs
Various drugs help control breathing and throat and lung infections.
A special diet and drugs help with food absorption
In the future, gene therapy may be used to replace the faulty gene

7. Brittle Bone Disease
Children born with brittle bone disease have bones that develop without the right amount or type of protein called collagen.
They are at high risk of fracturing or breaking their bones easily.

8. Treatment for Brittle Bone Disease
- Physiotherapy
- Assistive equipment
- Drug treatments to help strengthen their bones
Penny’s Story:

9. What is Phenylketonuria?
A rare genetic disorder that prevents a child from breaking down phenylalanine (an amino acid found in milk, meat and eggs)
If a child with PKU eats these foods, there is a build-up of harmful substances in the body that damages brain development.

11. Phenylketonuria

12. Phenylketonuria All babies in the UK are screened for it at birth
Treatment begins with a special diet (including tyrosine supplementation) and medication to prevent the build-up of harmful substances.
A baby born with PKU wouldn’t meet developmental milestones as their brain becomes damaged, resulting in severe learning difficulties and death.

13. Treatment for Phenylketonuria
Tyrosine is used to improve alertness, attention and focus. It produces important brain chemicals that help nerve cells communicate and may even regulate mood
If a child has PKU, they may take Tyrosine supplements

14. Huntington’s Disease What is Huntington’s Disease?
Living with HD

15. Huntington’s Disease
Huntington’s Disease is an inherited neurodegenerative genetic disorder that causes progressive damage to certain nerve 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 and judgement affected.

16. Huntington’s Disease

18. Klinefelter Syndrome
Klinefelter syndrome is where boys and men are born with an extra X chromosome (XXY)
Boys and men with Klinefelter syndrome are still genetically male, and often will not realise they have this extra chromosome, but occasionally it can cause problems that may require treatment.
Klinefelter syndrome is quite common, affecting around 1 in every 660 males.

19. Causes of Klinefelter Syndrome
Klinefelter syndrome isn't directly inherited – the additional X chromosome occurs as a result of either the mother's egg or the father's sperm having the extra X chromosome (an equal chance of this happening in either), so after conception the chromosome pattern is XXY rather than XY.
his chromosome carries extra copies of genes, which interfere with the development of the testicles and mean they produce less testosterone (male sex hormone) than usual.
This change in the egg or sperm seems to happen randomly. If you have a son with the condition, the chances of this happening again are very small.
However, the risk of a woman having a son with Klinefelter syndrome may be slightly higher if the mother is over 35 years of age.

20. Symptoms of Klinefelter Syndrome
Klinefelter syndrome doesn't usually cause any obvious symptoms early in childhood, and even the later symptoms may be difficult to spot. Many boys and men don't realise they have it.
Possible features, which aren't always present, may include:
in babies and toddlers – learning to sit up, crawl, walk and talk later than usual, being weaker, quieter and more passive than usual
in childhood – shyness and low self-confidence, problems with reading, writing, spelling and paying attention, mild dyslexia and/or dyspraxia, low energy levels, difficulty socialising or expressing feelings
in teenagers – growing taller than expected for the family (with long arms and legs), broad hips, poor muscle tone and slower than usual muscle growth, reduced facial and body hair that starts growing later than usual, a small penis and testicles, enlarged breasts (gynaecomastia)
in adulthood – inability to have children naturally (infertility) and a low sex drive, in addition to the physical characteristics mentioned above

21. Klinefelter Syndrome

22. Health problems associated with Klinefelter Syndrome
Men with Klinefelter syndrome are at a slightly increased risk of developing other health problems, including:
type 2 diabetes
weak and fragile bones (osteoporosis)
cardiovascular disease and blood clots
autoimmune disorders (where the immune system mistakenly attacks the body), such as lupus
an underactive thyroid gland (hypothyroidism)
anxiety, learning difficulties and depression – although intelligence is usually unaffected
male breast cancer – although this is very rare

23. Treatment for Klinefelter Syndrome
testosterone replacement therapy
speech and language therapy during childhood to help with speech development
educational and behavioural support at school to help with any learning difficulties or behaviour problems
occupational therapy to help with any co-ordination problems associated with dyspraxia
Physiotherapy to help build muscle and increase strength
psychological support for any mental health issues
fertility treatment – options include artificial insemination using donor sperm or possibly intra-cytoplasmic sperm injection (ICSI), where sperm removed during a small operation are used to fertilise an egg in a laboratory
breast reduction surgery to remove excess breast tissue

24. Down’s Syndrome Life Stories:

25. Down’s Syndrome Characteristics of Down’s Syndrome:
Down’s Syndrome is a genetic condition that typically causes some level of learning disability and certain physical characteristics.
Characteristics of Down’s Syndrome:
floppiness (hypotonia)
eyes that slant upwards and outwards
a small mouth with a tongue that may stick out
a flat back of the head
below-average weight and length at birth
their palm may have only one crease across it
Although children with Down's syndrome share some common physical characteristics, they don't all look the same. A child with Down's will look more like their family members than other children who have the syndrome.
People with Down's syndrome will also have different personalities and abilities. Everyone born with Down's syndrome will have some degree of learning disability, but this will be different for each person.

26. Testing for Down’s Syndrome

27. Causes of Down’s Syndrome
Down's syndrome is usually caused by an extra chromosome in a baby's cells. In most cases, this isn't inherited – it's simply the result of a one-off genetic change in the sperm or egg.
There's a small chance of having a child with Down's syndrome with any pregnancy, but the likelihood increases with the age of the mother.
For example, a woman who is 20 has about a 1 in 1,500 chance of having a baby with Down's, while a woman who is 40 has a 1 in 100 chance.
There's no evidence that anything done before or during pregnancy increases or decreases the chance of having a child with Down's syndrome.

28. Living with Down’s Syndrome
Although there's no "cure" for Down's syndrome, there's support available to help children with the condition lead healthy, fulfilling lives.
This includes:
access to good healthcare – including a range of different specialists
support for your child's development – this may include speech and language therapy, physiotherapy, and home teaching 
support groups – such as the Down's Syndrome Association, who can put you in touch with other families who have a child with Down's syndrome
Lots of people with Down's syndrome are able to leave home, have relationships, work, and lead largely independent lives.

29. Health problems linked to Down's syndrome
People with Down's syndrome are more likely to have certain health problems, including:
heart disorders, such as congenital heart disease
hearing and vision problems
thyroid problems, such as an underactive thyroid gland (hypothyroidism)
recurrent infections, such as pneumonia
Your child may be checked by a paediatrician more often than other children to pick up problems as early as possible. 

30. What is Colour Blindness
Colour (color) blindness (colour vision deficiency, or CVD) affects approximately 1 in 12 men (8%) and 1 in 200 women in the world. In Britain this means that there are approximately 3 million colour blind people (about 4.5% of the entire population), most of whom are male
Most colour blind people are able to see things as clearly as other people but they are unable to fully ‘see’ red, green or blue light. There are different types of colour blindness and there are extremely rare cases where people are unable to see any colour at all.
a red/green colour blind person will confuse a blue and a purple because they can’t ‘see’ the red element of the colour purple

31. Causes of Colour Blindness
Colour blindness is a usually a genetic (hereditary) condition (you are born with it).
Red/green and blue colour blindness is usually passed down from your parents.
The gene which is responsible for the condition is carried on the X chromosome and this is the reason why many more men are affected than women.

32. Types of Colour Blindness - Trichromacy
Normal colour vision uses all three types of light cones correctly and is known as trichromacy. People with normal colour vision are known as trichromats.

33. Types of Colour Blindness – Anomalous Trichromacy
People with ‘faulty’ trichromatic vision will be colour blind to some extent and are known as anomalous trichromats. In people with this condition all of their three cone types are used to perceive light colours but one type of cone perceives light slightly out of alignment, so that there are three different types of effect produced depending upon which cone type is ‘faulty’.
The different anomalous conditions are protanomaly, which is a reduced sensitivity to red light, deuteranomaly which is a reduced sensitivity to green light and is the most common form of colour blindness and tritanomaly which is a reduced sensitivity to blue light and is extremely rare.

34. Types of Colour Blindness – Monochromacy
Monochromacy (achromatopsia) - People with monochromatic vision can see no colour at all and their world consists of different shades of grey ranging from black to white, rather like only seeing the world on an old black and white television set. Achromatopsia is extremely rare, occuring only in approximately 1 person in 33,000 and its symptoms can make life very difficult. Usually someone with achromatopsia will need to wear dark glasses inside in normal light conditions.

35. Treatment for Colour Blindness
There is currently no treatment for inherited colour blindness.
Colour filters or contact lenses can be used in some situations to enhance the brightness between some colours and these are occasionally used in the workplace, but many colour blind people find these actually confuse them further rather than help.
There is hope on the horizon for a ‘cure’ for inherited colour vision deficiency using gene technology. This will involve injecting genetic material into the eye so is not for the faint-hearted! At the moment there have been no trials on humans but the process has been proved to work in monkeys.

36. Colour Blindness Test

37. Duchenne Muscular Dystrophy

38. Duchenne Muscular Dystrophy
What is Duchenne muscular dystrophy?
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness. It is one of nine types of muscular dystrophy.
DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. Symptom onset is in early childhood, usually between ages 3 and 5. The disease primarily affects boys, but in rare cases it can affect girls

39. Duchenne Muscular Dystrophy
What are the symptoms of DMD?
Muscle weakness can begin as early as age 3, first affecting the muscles of the hips, pelvic area, thighs and shoulders, and later the skeletal (voluntary) muscles in the arms, legs and trunk. The calves often are enlarged. By the early teens, the heart and respiratory muscles also are affected

40. Duchenne Muscular Dystrophy
What causes DMD?
In 1986, MDA-supported researchers identified a particular gene on the X chromosome that, when flawed (mutated), leads to DMD.
In 1987, the protein associated with this gene was identified and named dystrophin. Lack of the dystrophin protein in muscle cells causes them to be fragile and easily damaged.
DMD has an X-linked recessive inheritance pattern and is passed on by the mother, who is referred to as a carrier
DMD carriers are females who have a normal dystrophin gene on one X chromosome and an abnormal dystrophin gene on the other X chromosome. Most carriers of DMD do not themselves have signs and symptoms of the disease, but a minority do.

41. Duchenne Muscular Dystrophy
Medical Management
Thanks to advances in many areas of medicine, such as cardiology and pulmonology, people with Duchenne muscular dystrophy in the 21st century are living longer than in previous decades, often well into adulthood.
Braces, standing frames and wheelchairs
Cardiac care
Contractures
Diet - high in fluid and fibre, with fresh fruits and vegetables dominant
Exercise
Medications - corticosteroids
Physical and occupational therapy
Respiratory care
Spine-straightening surgery

42. Susceptibility to disease
Most diseases involve many genes in complex interactions, in addition to environmental influences.
An individual may not be born with a disease but may be at high risk of acquiring it. This is called as genetic predisposition or susceptibility.
The genetic susceptibility to a particular disease due to the presence of one or more gene mutations, and/or a combination of alleles need not necessarily be abnormal.
 In some cases, such as cancer, individuals are born with genes that are altered by lifestyle habits or exposure to chemicals.

43. Cancer
Cancer is a condition where cells in a specific part of the body grow and reproduce uncontrollably. The cancerous cells can invade and destroy surrounding healthy tissue, including organs
More than 1 in 3 people will develop some form of cancer during their lifetime. In the UK, the 4 most common types of cancer are:
breast cancer
lung cancer  
prostate cancer 
bowel cancer
There are more than 200 different types of cancer, and each is diagnosed and treated in a particular way. You can find links on this page to information about other types of cancer

44. Cancer Spotting signs of cancer
Changes to your body's normal processes or unusual, unexplained symptoms can sometimes be an early sign of cancer.
Symptoms that need to be checked by a doctor include:
a lump that suddenly appears on your body
unexplained bleeding
changes to your bowel habits

45. Cancer Reducing your risk of cancer healthy eating
taking regular exercise
not smoking

46. Cancer Cancer treatment
chemotherapy – powerful cancer-killing medication
radiotherapy – the controlled use of high-energy X-rays

47. Diabetes
Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.
There are 2 main types of diabetes:
type 1 diabetes – where the body's immune system attacks and destroys the cells that produce insulin
type 2 diabetes – where the body doesn't produce enough insulin, or the body's cells don't react to insulin
During pregnancy, some women have such high levels of blood glucose that their body is unable to produce enough insulin to absorb it all. This is known as gestational diabetes.

48. Diabetes

50. Diabetes Causes of diabetes
The amount of sugar in the blood is controlled by a hormone called insulin, which is produced by the pancreas (a gland behind the stomach).
When food is digested and enters your bloodstream, insulin moves glucose out of the blood and into cells, where it's broken down to produce energy.
However, if you have diabetes, your body is unable to break down glucose into energy. This is because there's either not enough insulin to move the glucose, or the insulin produced doesn't work properly.
Although there are no lifestyle changes you can make to lower your risk of type 1 diabetes, type 2 diabetes is often linked to being overweight.

51. Diabetes Treating diabetes
In type 1 diabetes your pancreas no longer makes insulin, so you have to inject it to control your blood glucose levels.
In type 2 diabetes you can alter your diet and lifestyle to help your body control the diabetes, you may also need to take medicines such as metformin to help lower blood sugar levels

52. High Blood Cholesterol
What is cholesterol?
Cholesterol is a fatty substance in our blood, which is produced naturally in the liver. Everyone has cholesterol. We need it to stay healthy because every cell in our body uses it. Some of this cholesterol comes from the food that we eat.
There are two main types of cholesterol – one is 'good' and the other is 'bad'. Having too much 'bad' cholesterol can cause problems. It can clog up the arteries carrying blood around your body. This can cause heart and circulatory diseases like a heart attack or stroke.

53. High Blood Cholesterol
What causes high cholesterol?
Things that cause high cholesterol you can control
eating a lot of saturated fat
smoking
not being active enough
having too much body fat, especially around your middle.
Things that cause high cholesterol you can't control
getting older
if you are male or female
ethnic background
Familial Hypercholesterolemia (FH) and other inherited diseases.

54. High Blood Cholesterol
What can I do to lower my cholesterol?
Eat a healthy balanced diet - Eating more fruit, vegetables and wholegrain is better than eating foods high in saturated fat and sugar.
Be active for at least 30 minutes a day
Stop smoking

55. Biological Factors that affect development
Foetal Alcohol syndrome
Maternal infections during pregnancy
Lifestyle/diet during pregnancy
Congenital defects

56. Foetal Alcohol Syndrome
If a woman drinks alcohol during pregnancy, she risks damaging her baby. Sometimes this can result in mental and physical problems in the baby, called foetal alcohol syndrome.
Alcohol in the mother's blood passes to her baby through the placenta.
The baby can't process alcohol as well as the mother can, which means it can damage cells in their brain, spinal cord and other parts of their body, and disrupt their development in the womb.
This can result in the loss of the pregnancy. Babies that survive may be left with the lifelong problems described below.
a head that's smaller than average
poor growth – they may be smaller than average at birth, grow slowly as they get older, and be shorter than average as an adult
distinctive facial features – such as small eyes, a thin upper lip, and a smooth area between the nose and upper lip, though these may become less noticeable with age
movement and co-ordination problems, known as cerebral palsy
learning difficulties – such as problems with thinking, speech, social skills, timekeeping, maths or memory
mood, attention or behavioural problems – such as autism-like behaviour or attention deficit hyperactivity disorder (ADHD)
problems with the liver, kidneys, heart or other organs
hearing and vision problems

57. Foetal Alcohol Syndrome

58. Maternal Infections During Pregnancy
Chickenpox
Before 28 weeks pregnant: there's a small risk your baby could develop foetal varicella syndrome (FVS). FVS can damage the baby's skin, eyes, legs, arms, brain, bladder or bowel.
Between weeks 28 and 36 of pregnancy: the virus stays in the baby's body but doesn't cause any symptoms. However, it may become active again in the first few years of the baby's life, causing shingles.
After 36 weeks of pregnancy: your baby may be infected and could be born with chickenpox.
CMV (cytomegalovirus)
is a common virus that's part of the herpes group, which can also cause cold sores and chickenpox
it can cause problems for unborn babies, such as hearing loss, visual impairment or blindness, learning difficulties and epilepsy.
Group B streptococcus
This can cause life threatening problems including blood poisoning (septicaemia), infection of the lung (pneumonia) and infection of the lining of the brain (meningitis). In the long term it can cause deafness, blindness, learning difficulties and cerebral palsy
Infections transmitted by animals
Cat faeces may contain toxoplasma – an organism that causes toxoplasmosis infection. Toxoplasmosis can damage your baby.
Lambs and sheep can carry an organism called Chlamydia psittaci, which is known to cause miscarriage in ewes. They also carry toxoplasma.
pigs can be a source of hepatitis E infection. This infection is dangerous in pregnant women, so avoid contact with pigs and pig faeces
Hepatitis B
If you have hepatitis B or are infected during pregnancy, you can pass the infection on to your baby at birth.
Hepatitis C
The hepatitis C virus infects the liver.

59. Maternal Infections During Pregnancy
Herpes
Genital herpes infection can be dangerous for a newborn baby. Sometimes neonatal herpes will only affect the baby's eyes, mouth or skin. In these cases, most babies will make a complete recovery with antiviral treatment.
it can affect the skin, eyes, mouth, central nervous system, and/or even spread to internal organs via disseminated disease which can cause organ failure and lead to death
Nearly a third of infants with this type of neonatal herpes will die, even after they have been treated.
HIV
current evidence suggests an HIV-positive mother in good health and without symptoms of the infection is unlikely to be adversely affected by pregnancy.
However, HIV can be passed from a pregnant woman to her baby during pregnancy, birth or breastfeeding.
Parvovirus B19 (slapped cheek syndrome) 
causes a characteristic red rash on the face . Parvovirus is highly infectious and can be harmful to the baby.
Rubella (German measles)
if you develop rubella in the first 4 months of pregnancy, it can lead to serious problems, including birth defects and miscarriage
Sexually transmitted infections (STIs)
STIs can affect your baby's health both during pregnancy and after the birth.
Toxoplasmosis
toxoplasmosis infection through contact with cat faeces. If you're pregnant, the infection can damage your baby, it can cause miscarriage, stillbirth or damage to the baby’s brain and other organs, particularly the eyes
Zika virus
There's evidence the Zika virus causes birth defects if a woman catches it when she's pregnant. In particular, it can cause the baby to have an abnormally small head (microcephaly).

60. Lifestyle / Diet during pregnancy
During pregnancy it is important to continue to eat a healthy balanced diet. You should not eat the following if you are pregnant:
Anything with a lot of vitamin A. You need a small amount of vitamin A to keep healthy. However, large amounts can harm an unborn baby. So, avoid: Liver and liver products such as liver pâté and cod liver oil supplements.
Food which may have high levels of listeria. Pregnant women are more likely to become infected with listeria and it sometimes causes miscarriage, stillbirth or infections in the baby after birth. Foods which are most at risk of carrying listeria are:Undercooked meats and eggs. This may occur in some pre-cooked meats and pre-prepared meals. Make sure all meat foods are cooked until piping hot. Eggs should be cooked until the white and yolk are solid. Avoid foods that may contain raw eggs, such as some types of mayonnaise and mousse.
Mould-ripened and soft cheeses such as Brie, Camembert and blue-veined cheeses. (Hard cheeses and processed cottage cheese are safe.)
Pâtés - including vegetable pâtés.
Raw shellfish and raw fish (more detail below).
Unpasteurised milk. Note: goat's milk is often unpasteurised, and goat's milk products such as cheeses are often made from unpasteurised milk.
Certain fish. Aim to eat at least two portions of fish per week, with at least one portion being oily fish. However, some types of fish contain a high level of mercury which can damage the developing nervous system of an unborn baby. Because of this, the Food Standards Agency (FSA) advises: You should not eat any shark, marlin or swordfish.
Limit tuna - eat no more than four medium-sized cans or two fresh tuna steaks per week
Avoid eating raw fish or uncooked shellfish which may contain germs (bacteria, viruses or parasites).

61. Lifestyle / Diet during pregnancy
Limit the amount of caffeine to no more than 300 mg per day. Having a lot of caffeine increases your risk of having a miscarriage and a baby with low birth weight. The increased risk is small. But, it is best to play safe.
Smoking
Women who are pregnant should avoid smoking, due to the damage it can cause the unborn baby and the long-term effects on the health of your child after birth.
Alcohol
Women who are pregnant should not drink alcohol., as it can cause damage to a developing baby
At worst, babies can develop a syndrome of severe abnormalities, called foetal alcohol syndrome. In others, alcohol can cause problems for the baby such as poor growth, premature labour and physical and mental disability.
Exercise
For most women, it is important to do some regular physical exercise during pregnancy as part of living a healthy lifestyle. There are some circumstances in which this may need to be modified, and there are some sports which are best avoided in pregnancy.

62. Lifestyle / Diet during pregnancy
Working during pregnancy
If you think that your job may pose a risk to a pregnancy then ideally you should discuss this with your employer before you become pregnant or as soon as you become pregnant.
Certain jobs and workplaces may pose a risk to a pregnancy, in particular to the early stages of pregnancy
Recreational drugs
The effects of all the different types of recreational (illicit) drugs on pregnancy are not fully known. However, there is an increasing amount of evidence to suggest that they are likely to pose a risk of damage to the baby
Animals
Avoid contact with sheep and lambs at lambing time. This is because some lambs are born carrying the germs that cause listeriosis, toxoplasmosis and chlamydia. 
Travel
In general it is safe to travel during pregnancy. When in a car, wear the seat belt so that the straps go above and below your bump, not across it.
Flying is not known to be harmful. Most airlines will not allow you to fly in the late stages of pregnancy, because planes are not the ideal place to go into labour, and they would prefer not to divert the flight to take you to the nearest hospital.
It makes sense not to travel to anywhere too remote and far from medical assistance, particularly in the early or later stages of pregnancy.
Not all travel vaccinations are safe to use in pregnancy, so consider your destination carefully. If possible avoid travel to destinations where malaria is prevalent, as pregnant women are more likely to be bitten and more likely to have complications if they develop the disease. Also avoid areas where Zika virus is circulating if possible, due to the risk of abnormalities in babies.

63. Congenital defects
Most babies are born healthy, but when a baby has a condition that is present from birth, it is called a congenital disorder. Congenital disorders can be inherited or caused by environmental factors and their impact on a child’s health and development can vary from mild to severe. A child with a congenital disorder may experience a disability or health problems throughout life.
Common congenital defects include:
cleft lip and cleft palate
cerebral palsy
Fragile X syndrome
Down syndrome
spina bifida
cystic fibrosis
heart conditions.