Genetic Disorders Flashcards
How common is CF?
1/2500 live births
How is CF usually picked up?
In the Guthrie heel prick test of neonate
Prognosis of people with CF?
95% ultimately die of respiratory failure
Median age of death is 29yrs, projected life 36 years
Cause of CF?
Chromosome 7 mutations (delta F508)
CFTR protein altered, Cl- ion channel, secretions are dehydrated
Respiratory effects of CF?
Defective mucociliary clearance, mucus obstruction and infection and inflammation. Recurrent chest infections, pneumothorax Productive cough, lots of sputum that is sticky, air trapping, wheeze, clubbing Pseudomonas aeruginosa, staphylococcus aureus, haemophilus influenza
GI effects of CF
Meconium ileus, pancreatic secretion failure, deficiency of enzymes leads to malabsorption
Failure to thrive
Foul smelling pale, floating faeces.
Complications of CF
Diabetes mellitus (pancreatic failure)
Liver disease
Male infertility
Sinusitis
How is CF diagnosed?
Sweat test (high chloride concentration) Genetic testing
Describe CF diabetes
Usually diagnosed over aged 30
HbA1c not useful
Management of CF
Physio BD
Chest percussion
Continuous prophylactic antibiotics (fluclox)
Nebulisers
Creon for pancreatic enzyme insufficiency
Vitamins A, D, E, K
High calorie diet
Treatment of end stage CF
Lung transplantation
What are the 2 types of muscular dystrophy?
Duchenne
Becker’s
Describe Duchenne MD
Severe inherited disorder of muscle weakness
X linked recessive, males affected
1/3500 male births
Female sisters have 50% chance of being a carrier
Dystrophin instability, influx of Ca2+ then necrosis
Failure to produce dystrophin
Signs of Duchenne’s MD
- Gower’s sign (hands to climb up to stand on legs)
* Waddling gait, muscle wasting, calf hypertrophy, absent reflexes
Chronology of Duchenne MD
- Severe disability by aged 10
* Death before the age of 30 due to cardiac and respiratory involvement
Diagnosis of Duchenne MD
Creatine Kinase ++
Abnormal EMG
MRI of muscles
Muscle biposy