Metabolic Flashcards
Hypokalaemic metabolic alkalosis
Hypercalciuria
Raised renin, aldosterone and prostaglandin E
Bartter syndrome
When does maple syrup urine disease present?
First week of life (breastfeeding can delay onset until second week)
Presenting symptoms of maple syrup urine disease?
Lethargy Irritability Poor feeding Focal neurology - abnormal movements and increasing spasticity Opisthotonus Convulsions + coma
What is the unique finding in maple syrup urine disease?
Characteristic maple odour in urine and earwax within a day or two of birth
How do you confirm a diagnosis of maple syrup urine disease?
Raised amino acids (leucine, isoleucine, valine)
How does galactosaemia present?
First 2 weeks of life Poor feeding Vomiting Jaundice Hepatomegaly
How does methylmalonic academia present?
Few months into life
Neurological manifestations
Abnormally high methylmalonic acid in blood and urine
How does PKU present?
In infancy Lethargy Feeding difficulties Unusually light eyes, skin and hair Musty odour Eczematous rash Developmental delay
Biochemical findings in urea cycle defects?
Raised ammonia
Abnormal levels of intermediate molecules of the urea cycle (arginine, citrulline, others)
How to treat acute illness in urea cycle defect with high ammonia?
Stop feeds (Take away protein load)
IV 10% dextrose
Remove ammonia with sodium benzoate
Cause of Hunter’s disease
Deficiency of lysosomal enzymes that degrade GAGs, causing accumulation and excessive urinary excretion of GAGs
Features of Hunter’s disease
Coarsening facies Developmental delay Heart murmur Hepatomegaly Joint stillness Inguinal hernias Short stature Hydrocephalus
Investigations in suspected Hunter’s disease
Echo
Urinary GAGs
Enzyme studies
Skeletal X-rays
What is Hunter’s disease also known as?
MPS type II
Cause of vitamin D dependent rickets type 1
Mutation in gene for enzyme 1 alpha-hydroxylate; therefore 1,25 vit D is low
Treatment of vitamin D dependent rickets type 1
High dose vitamin D or 1 alpha-calciferol
Diagnosis of rickets with raised or normal ALP, normal 1,25 fit D and low 25-hydroxycholecalciferol?
Nutritional rickets
Cause of Gaucher’s disease
Glucocerebrosidase deficiency
Most common lysosomal storage disease?
Gaucher’s
Typical presentation of Gaucher’s
Tiredness
Organomegaly
Bone pain
Diagnostic test for Gaucher’s
Enzyme studies
Investigations that should be done in suspected Gaucher’s
Bone marrow aspirate
Leg X-ray
Ultrasound abdomen
What will a bone marrow aspirate find in Gaucher’s?
Classic glycolipid-laden macrophages
What will a leg X-ray show in Gaucher’s?
Erlenmeyer flask deformities
When do you see microcytic anaemia with hyperhsegmented neutrophils?
Folic acid or B12 deficiency
Global delay Microcephaly Muscular hypotonia External ophthalmoplegia Elevated lactate
Suggests?
Mitochondrial disease
Cause of mitochondrial disorders?
Defects in the respiratory chain (complexes I to V) which are involved in producing cellular ATP
Strongly consider a mitochondrial disorder in patients with:
Muscular disease + involvement of 2 additional systems
CNS disease and involvement of 2 additional systems
Multisystem disease (at least 3 systems) and involvement of muscle and/or CNS
Initial investigations in suspected mitochondrial disease?
Organic acids
CSF lactate
MRI brain
Muscle biopsy
Presentation of MCADD
First 3 years of life
Hypoglycaemia
Hepatomegaly
Sudden death, possibly brought on by a period of fasting or vomiting
Blood tests in MCADD
Low bicarb
Anion gap
Hypoglycaemia in absence of ketons
Mild to moderately high ammonia
Blood tests in organic acidurias
Metabolic acidosis with ketosis
Elevated lactate
Mild to moderate hyperammonaemia
What do reducing substances in the urine suggest?
Galactosaemia
Most reliable test for galactosaemia?
Galactose-1-phosphate uridyltransferase in the blood
Presentation of infantile Tay-Sachs disease
Ashkenazi Jewish 3-6 months Mild muscle weakness Myoclonic jerks Exaggerated startle response
