Nitrogen 3 Flashcards
<p>What are inherited metabolic disorders?</p>
<p>Group of genetic diseases involving metabolic defects</p>
<p>What are interited metabolic disorders usually due to?</p>
<p>A single gene</p>
<p>What do inherited metabolic disorders usually result in?</p>
<p>Deficiencies of key enzymes</p>
<p>What does the deficiency of key enzymes cause?</p>
<p>Abnormal synthesis of proteins, amino acids, carbohydrates or lipids</p>
<p>Are inherited metabolic disorders common?</p>
<p>No, they are typically rare</p>
<p>What are the consequences of a key enzyme defect?</p>
<p></p>
<p>Decreased formation of desired product</p>
<p>Accumulation of substance before the enzyme with the defect</p>
<p>Increase formation of other, unwanted metabolites</p>
<p>What kind of inheritance do most inherited metabolic disorders show?</p>
<p>Autosomal reccesive inheritance</p>
What does autosomal dominance inheritance look like?
What does autosomal recessive inheritance look like?
<p>What are some common clinical features of inherited metabolic disorder presening in childhood?</p>
<p>Acidosis</p>
<p>Failure to thrive</p>
<p>Vomiting</p>
<p>CNS dysfunction</p>
<p>Hypoglycaemia</p>
<p>Unusual odour</p>
<p>Why do proteins need to be immedietely metabolised?</p>
<p>There is no storage facility like carbohydrates</p>
<p>Where does the urea cycle happen?</p>
<p>Split between the mitochondrial matrix and cytosol</p>
<p>What happens in the urea cycle?</p>
<p>Ammonia goes in and urea comes out</p>
<p>What are urea cycle defects?</p>
<p>Defects in any of the 6 enzymes involved</p>
<p>How many inherited disorders of the urea cycle are there?</p>
<p>6</p>
<p>What is the most common inherited urea cycle defect?</p>
<p>OTC deficiency</p>
<p>What kind of inheritance is OTC dificiency?</p>
<p>X linked inheritance</p>
<p>What inherited urea cycle defects have autosomal inheritance?</p>
<p>All of them apart from OTC dificiency</p>
<p>What does OTC dificiency cause?</p>
<p>Hyperammoniaemia, which is elevated blood ammonia which is highly toxic</p>
<p>What could amino acids be metabolised into?</p>
<p>Other amino acids</p>
<p>Hormones</p>
<p>Pigments</p>
<p>Neurotransmitters</p>
<p>What do inherited gene defects cause?</p>
<p>Decreased enzyme activity</p>
<p>What does decreased enzyme activity cause?</p>
<p>Decreased product</p>
<p>Increased precurder</p>
<p>Alternative metabolic products that may be toxic</p>
<p>What is phenylketonuria (PKU)?</p>
<p>Absence/dificiency of phenylalanine hydroxylase (PAH)</p>
<p>What kind of inherited disorder is PKU?</p>
<p>Autosomal recessive disorder</p>
<p>What does PKU cause?</p>
<p>Increased phenylalanine levels which is toxic, and the production of alternative metabolic products</p>
<p>What happens to untreated people with PKU?</p>
<p>Impaired brain development</p>
<p>What can the alternative metabolic products produced due to PKU do?</p>
<p>Cross the blood brain barrier and cause irreversible neurological damage</p>
<p>What are clinical factors of PKU?</p>
<p>Normal at birth</p>
<p>Phenylalanine rises rapidly after feeding is established</p>
<p>Delayed brain development visible by 6 months</p>
<p>How is PKU diagnosed?</p>
<p>Screening test</p>
<p>Confirmation of increased phenylalanine in the lab</p>
<p>Decreased blood tyrosine levels</p>
<p>What is the treatment of PKU?</p>
<p>Low protein diet</p>
<p>Maintain bloody phenylalanine levels</p>
<p>Maintain blood tyrosine levels at the upper limit</p>
