B2 - Genetic factors that affect development Flashcards
Name conditions caused by dominant genes
- Brittle Bone Disease
- Huntingdon’s disease
Explain brittle bone disease
- Osteogenesis imperfecta is a genetic condition present from birth.
- Its primary feature is fractures usually caused by minimal impact.
- Osteogenesis Imperfecta is a defect where collagen (the protein that is responsible for bone structure) is missing, reduced or of low quality.
So it’s not enough to support the minerals in the bone.
- This makes the bone weak, which in turn makes the bones easy to fracture.
What are the symptoms of brittle bone disease?
Symptoms include:
- Fractures can occur with minimal force - this varies from child to child.
- Bones may have an altered shape, for example, they may be shortened or bowed.
- The whites of the eye may appear more blue or grey than normal.
- Joints can be hyper-mobile or very flexible.
- Some degree of joint or bone pain may be present.
- Problems with formation of teeth (detinogenesis)
- Children with OI may tire easier than other children.
- Hearing problems are known to affect people with OI usually after puberty.
- Children with OI tend to be shorter than other children.
How can brittle bone disease be treated?
- The majority of patients with mild or moderate OI are treated with physiotherapy and management of symptoms as they occur.
- The main medications used are called pamidronate and zoledronic acid. Both are a type of bisphosphonate, which is a medicine that prevents loss of bone mass.
What are the P,I,E & S impacts of brittle bone disease?
- Physical: have hypermobile (very flexible) joints:- this means that they are more prone to sprains and may have weaknesses around their joints. Wearing supportive shoes and trainers rather than plimsolls.
- Intellectual: Could cause cerebral atrophy, hydrocephalus and cerebellar hypoplasia.
- Emotional: problems with self esteem and self concept. Caring for a child with OI can put a strain on marriage.
- Social: tend to struggle with friendships and may be in hospital a lot so they miss out on making connections/relationships.
Explain Huntingdon’s disease.
- Huntingdon’s disease is a condition that stops parts of the brain from working properly overtime. Its passed on (inherited) from a person’s parents.
- It gets gradually worse over time and is usually fatal after a period of up to 20 years.
Symptoms of Huntingdon’s disease
- difficulty concentrating and memory lapses.
- depression.
- stumbling and clumsiness.
- involuntary jerking or fidgety movements of the limbs and body.
- mood swings and personality changes.
- problems swallowing, speaking and breathing.
- difficulty moving.
How can Huntington’s disease be treated?
- There’s no cure for Huntington’s disease but medication and therapies can help treat some of the symptoms.
- Speech and language therapy and occupational therapy can help with communication and day to day living.
- Regular exercise is also very important.
What are the P, I, E & S impacts of Huntingdon’s disease?
- Physical: Slurred speech and problems with swallowing, eating , speaking and especially walking.
- Intellectual: Decline in thinking and reasoning skills, memory, concentration, judgement, and ability to plan and organise.
- Emotional: lack of emotions and not recognising the needs of others . Periods of aggression, excitement, depression, antisocial behaviour and anger.
- Social: discrimination, lack of understanding and social isolation.
Name conditions caused by recessive genes
- Cystic Fibrosis
- Phenylketonuria
- Duchenne Muscular Dystrophy
Explain Cystic Fibrosis
- Cystic Fibrosis is an inherited condition that causes sticky mucus to build up in the lungs.
- This causes lung infections and problems with digesting food.
- Most cases of cystic fibrosis are picked up at birth using the newborn screening heel prick test.
- Symptoms usually start in early childhood and vary from child to child, but the condition gets slowly worse over time - lungs and digestive system become increasingly damaged.
- Life expectancy is shortened for those with cystic fibrosis.
Symptoms of Cystic Fibrosis
- Recurring chest infections.
- Wheezing, coughing, shortness of breath and damage to the air way.
- Difficulty putting on weight and growing.
- Yellowing of the skin, whites of eyes. (Jaundice).
- Diarrhoea, constipation, or large smelly faeces.
- A bowel obstruction in newborn babies (meconium ileus) - surgery may be needed.
How can cystic fibrosis be treated?
Cystic fibrosis isn’t curable but it can be treated in a number of ways such as:
- antibiotics to prevent and treat chest infections.
- medicines to make the mucus in the lungs thinner and easier to cough up.
- medicines to widen the airways and reduce inflammation.
- special techniques and devices to help clear mucus from the lungs.
P, I, E & S impacts of Cystic Fibrosis
- Physical: poor lung function, frequent and persistent lung infections and the inability to effectively digest food - particularly fats.
- Intellectual: cognitive deficits/cognitive impairment. Falling behind in school due to flare ups of Cystic Fibrosis spent in hospital.
- Emotional: embarrassment/low self esteem, guilt from the parents - feel as though it’s their fault. Increased anxiety/depression.
- Social: barriers to forming relationships, a lack of independence.
Explain Phenylketonuria
- Phenylketonuria is a rare but potentially serious inherited disorder.
- Our bodies break down the protein in foods - such as meat and fish, into amino acids that are the “building blocks” of protein.
- These amino acids are then used to make our own proteins.
- Any amino acids that are not needed are broken down further and removed from the body.
- People with Phenylketonuria cannot break down the amino acid phenylanine, which then builds up in their blood and brain. This can lead to brain damage.
- At around 5 days old, babies are offered newborn blood spot screening -> involves pricking the baby’s heel to collect blood to test.
- If its confirmed, treatment is given straight away.
Symptoms of Phenylketonuria
- Doesn’t usually cause any symptoms if treatment is started early,
- Without treatment, it can lead to brain damage + nervous system damage -> can cause learning disabilities.
Symptoms of untreated PKU include:
- Behavioural difficulties - temper tantrums, episodes of self-harm.
- Fairer skin, hair and eyes - than siblings who don’t have the condition.
- Eczema
- Repeatedly being sick
- Tremors/Jerking movements in arms and legs
- Epilepsy
- Musty smell to the breath, skin and urine.
How can Phenylketonuria be treated?
- A lifetime diet with very limited intake of foods with phenylalanine.
- Taking a PKU formula - a special nutritional supplement - for life to make sure that you get enough essential protein (without phenylalanine) and nutrients that are essential for growth and general health.
