Genetics Flashcards
Screening for down syndrome is done by
maternal age triple screening CUBS screening Selection for aminocentesis Free foetal DNA (private)
Pathology of cystic fibrosis
Defect of cellular chloride transport
Presentation of cystic fibrosis
Lung infections (acute/chronic) Pancreatic insufficiency
Diagnosis of cystic fibrosis
Immunoreactive trypsin (first 6 weeks)
Sweat test
Genotyping
Sickle cell disorders pathology
Abnormal HB gene
Presentation of sickle cell disorders
VERY painful cold dehydration infections jaundice stroke leg ulcers eyes kidneys
Why do we screen babies?
To enable early detection of pre-symptomatic babies
To enable early treatment to improve health
To reduce anxiety caused by uncertainty over symptoms before a clinical diagnosis is made
What conditions are screened for?
Phenylketonuria (PKU) Congenital hypothyroidism (CHT) Sickle cell disorders Cystic fibrosis (CF) MCADD Homocyste inuria Isovaleric acidaemia Maple syrup urine disease Glut aric aciduria type 1
Presentation of PKU if untreated
untreated babies go onto develop serious, irreversible mental disability
Pathology of PKU
unable to break down phenylalanine (an amino acid in protein)
Treatment of PKU
Strictly controlled diet should start by 21 days old
Pathology of MCADD
cannot break down fat to make energy for the body
Treatment of MCADD
avoid fasting and monitor frequency of meals to prevent metabolic crisis
emergency regimen; glucose polymer (maxijul) and IV dextrose
Levels of AFP in NT defects
Increased
AFP Levels in Down’s syndrome
Decreased
