Lecture 11: Inherited Metabolic Diseases Flashcards
When do inherited metabolic diseases present in life?
Early in childhood but can present more widely
What causes the IMD to present? (2)
Build up of precursor/intermediary metabolite
Product deficiency
What factors are used to classify IDM?
Disorders that give rise to intoxication
Disorders involving energy metabolism
Disorders involving complex molecules
What does intoxication mean in the context of IMD?
Too toxic of an environment for cells to survive.
PKU, Porphyria, Organic acidurias (MMA), urea cycle defects, Wilson disease, are examples of what type of IDM?
Disorders that give rise to intoxication
Mitochondrial defects, fatty acid oxidation defects (MCADD), Respiratory chain defects, are examples of what type of IDM?
Disorders involving energy metabolism
Lysosomal storage disorders, Gaucher disease, are examples of what type of IDM?
Disorders involving complex molecules
What can help diagnose IMD in symptomatic patients?
Clinical history
Genetic testing
Histology
Blood/urine test
What can help diagnose IMD in a whole population?
Screening programmes/Targeted screening
Why are urine tests helpful for blood disorders?
You can see crystals of the affected amino acid within the urine
ToD: All inherited disorders are life threatening
False
They can affect quality of life OR be life threatening
What is the name of the post-natal screening process?
Newborn blood spot (heel prick) test
What can the heel prick test test for? (8)
Phenylketonuria
Hypothyroidism
Cystic fibrosis
Sickle cell disease
MCADD
Galactosaemia
CAH
Duchenne muscular dystrophy
What can be seen in infants if they have a low level of phenylalanine?
Poor weight gain
Where can phenylalanine be found in foods?
High protein foods
Ingredient to Aspartame (artificial sweetener)
What does phenylalanine do in the body?
Helps the body use enzymes and amino acids in the body.
Can be converted into norephinephrine and epinephrine
Another name for Hypotonia
Floppy baby
Describe what you should see in a baby with Hypotonia (floppy baby)
Baby hangs there when held up. Completely limp inside of squirming and moving its legs.
Baby legs should tense and should bend like a v shape.