Question | Answer |
Ones to think about if child presents in first 1-3 weeks ? | -*Amino acidopathies
-MSUD
-PKU
-tyrosinemia
-*Urea cycle disorders
-*Galactosemia
-*Mitochondrial disorders
-*Peroxisomal
-*Fatty acid oxidation |
MSUD MoA ? | * can't break down branched chain amino acids (leucine, isoleucine, valine).....see well at birth and get after 3 days, hypoglycemia and met acidosis.... Urine smells like maple syrup |
MSUD tmt ? | * no BCAA and take thiamine and B1 |
PKU MoA ? | *PH deficiency - phenylalanine hydroxylase def...leads to high levels of phenyalanine, and no tyrosine is made....see fair skin/hair, musty odor, epilepsy, other hypopigmentations |
PKU tmt ? | * give tyrosine since you cant make it |
Maternal PKU and being pregnant ? | *phenylalanine is teratogenic, so can cause retardation, microceph, or heart defects |
*Organic Acidemias* | . |
Neonatal presentation ? | *Well at birth and for the first few days of life ----- *often lethal, and survivors often have significant physical and/or mental disabilities |
If metabolic acidosis with an anion gap, and elevated lactate ? | *Methylmalonic acidemia .....*Propionic acidemia |
Methylmalonic acidemia MoA and Tmt? | *autosomal recessive...defects in methylmalonyl-CoA mutase....* tmt = diet and B12..... *see massive urinary excretion of methylmalonic acid |
Propionic acidemia MoA ? | *autosomal recessive....*defects in propionyl-CoA carboxylase .... *see hyperammonemia, high plasma glycine; increased urinary excretion of 3-hydroxypropionic acid, methylcitrate, and tiglylglycine |
*Urea Cycle Disorders* | . |
Main thing we see that is different in urea cycle disorders ? | * no acidosis, but see respiratory alkalosis...with high serum amino acids |
Most common Urea cycle defect and also only X-linked ? | * OTC - see high levels of ornithine |
Consequences of Urea Cycle Disorders ? | * the high levels of ammonia can lead to neurological impairment |
*Carbohydrate Disorders* | . |
Classic Galactosemia ? | *Galactose-1-P uridyl transferase (GALT) deficiency --- cant break down Gal-1-P, and it is toxic |
Non-Classic Galactosemia ? | *Galactokinase deficiency - cant turn galactose in to Gal-1-P |
Galactosemia Cx ? | *newborn crash with vomiting diarrhea, jaundice, progressive liver and renal disease, increased risk of E.coli sepsis, progressive bilateral cataracts |
Glycogen Storage Disorders* | * |
von Gierke disease ? | *Glucose-6-phosphatase ---convulsions b cant metabolize glucose for energy, get hyperlipidemia/urcemia - skin xanthomas, and bleeding issues |
McArdle syndrome ? | *painful cramps with exercise |
*Fatty Acid Oxidation* | . |
MCAD deficiency basics ? | * major source of energy once hepatic glycogen stores become depleted during prolonged fasting and periods of higher energy demands.....* creates a fatal hypoglycemic state |
*Peroxisomal Disorders* | . |
Zellweger Syndrome ? | *most severe peroxisomal disorder.... *get over-accumulation of very long-chain fatty acids .... *see facial features such as a high forehead, underdeveloped eyebrow ridges, & wide-set eyes; & neurological abnormalities such as mental retarded |
*Lysosomal storage disorders* | . |
The single most common LSD is ? | *Gaucher disease - Progression leads to a vegetative state |
*Mucopolysaccharidoses* | . |
Hurler syndrome (MPS I) ? | *Nz = alpha- idurondase....* corneal clouding, coarse facies, short stature, dysostosis multiplex, organomegaly, heart disease, joint stiffness, mental retardation; diagnosed @ 6-24 months, childhood death |
Tay-Sachs Disease ? | *GM2 gangliosidosis - Lipid storage disease often results in distended neurons.....*A cherry-red spot is a finding in the macula |
Tay-Sachs Disease enzyme def ? | * Hexosamindase A |