Genetics/Genomics ~ NUR120

cystic fibrosis

• autosomal recessive disease

• diagnosed in utero or during newborn screening

• characterized by altered transport of sodium & chloride ions in & out of epithelial cells that secrete mucus —> leads to increased mucus

• mainly affects lungs, GI tract, reproductive tract, exocrine glands

s/s of CF

• x-ray: black is air & white is mucus

• lungs:

  • wheezing or SOB

  • coughing w/ thick mucus or blood

  • chronic bronchiolitis

  • frequent pneumonia

  • barrel chest

  • hyperinflation of lungs & air trapping

  • digital clubbing

• CV:

  • pulmonary HTN

  • Cor pulmonale

  • CHF

• RT:

  • delayed puberty

  • male: absent vas deferens (no transport of sperm)

  • female: thickened cervical mucus & menstrual irregularities & amenorrhea

• skin:

  • salty

  • metabolic alkalosis

• nose/sinuses

  • nasal polyps

  • frequent sinus infections

• MSK

  • osteopenia to osteoporosis —> due to lack of vitamin D absorption

• GI tract

  • failure to thrive & malnutrition

  • steatorrhea

  • GERD

  • diabetes

  • poor weight gain

  • pancreatitis

• meconium ileus

  • bowel obstruction in newborns when meconium is thicker/stickier than normal

• liver

  • neonatal jaundice

  • splenomegaly

  • later disease cirrhosis

assessment of CF

• history of frequent sinus & respiratory infections

• nasal polyps, sinus congestion

• work of breathing

• crackles or wheezing

• barrel chest

• bowel sounds (is there an obstruction?)

• tenderness over liver

diagnosis of CF

• family hx: 25% chance of disease if both parents are gene carriers

• through genetic testing, newborn screening, or chloride sweat test

  • CST: done if newborn screen is positive & infant is 10 days old (determines likelihood of disease not severity)

  • <40 mmol/L - normal & unlikely to have CF

  • 40-60 mmol/L - borderline & may need additional testing

  • >60 mmol/L - likely diagnosed

treatment for CF

airway clearance

• chest PT (percussion, vibration, postural drainage)

• therapy vest (shakes mucus loose)

• flutter valve (helps move mucus out)

• exercise —> improves lung function + moves secretions

bronchodilators

• Ex: albuterol, Ipratropium

• purpose: opens airways

mucolytics

• Dornase alfa

  • breaks down DNA in mucus

  • decreases exacerbations, increases airflow

• hypertonic saline (7%)

  • pulls water into airways

  • helps clear mucus

• BEST & cheapest mucolytic = WATER

oxygen therapy

• used if SpO2 levels are low

infection management

• antibiotics when infection suspected

  • may be oral, IV, inhaled

  • treat based on previous infection until sputum culture & sensitivity report is available

NO CURE

• trikafta (treats underlying cause, improves salt/water balance, makes mucus thinner & easier to clear

• lung transplant

• gene therapy

nutrition & digestion for CF

• pancreatic enzyme supplements

  • can open capsules & sprinkle on food (kids)

• diet

  • high calories

  • high protein

  • add vitamins if needed