Inborn Errors of Metabolism Flashcards
what happens in familial hypercholesterolaemia ?
- mutation on the Low Density Lipoprotein Receptor gene
- results in impaired LDL catabolism increasing plasma cholesterol.
*presents with Xanthomata
what happens in familial hypertriglyceridaemia ?
- hepatic overproduction of VLDL
- reduced HDL cholesterol level
- reduced conversion of VLDL to LDL
Causes (1) obesity (2) increased alcohol consumption (3)
IEM is classified based on intoxication effects into ;
1) Aminoacidopathies
2) Urea cycle defects
3) Organic acidemias
4) Disorders of carbohydrate metabolism
IEM classified based on energy deficiency state into ;
- medium chain acyl CoA dehydrogenase deficiency
- very long chain acyl CoA dehydrogenase deficiency
- carnitine uptake effect
- glycogen storage disease
IEM classified based on altered metabolism of complex molecules into ;
- lysosomal disorders
- peroxisomal disorders
- disorders of intercellular trafficking & processing
common lab presentation of IEM
1) neonatal hypoglycemia
2) jaundice/icterus
3) metabolic acidosis
4) lactic acidosis
5) neonatal hyperammonaemia
Diagnostic methods for prenatal diagnosis include
1) Chorionic volleys sampling (10-13wks)
2) Amniocentesis (14-20 wks)
3) DNA analysis
newborn screening was originally for the detection of what ?
Phenylketonuria
in sudden death _ is usually a common cause
FAO disorders
what enzyme is deficient in phenylketonuria
phenylalanine hydroxyalse
what causes Maple Syrup disease
- deficient carboxylation of leucine, isoleucine & valine
-inactivity of thiamine pyrophosphate
what enzyme is deficient in alkaptonuria
homogentisic acid oxidase
most common urea cycle deficiency ?
ornithine transcarbamylase
*sex linked
most common urea cycle deficiency ?
ornithine transcarbamylase
*sex linked
other urea cycle deficient enzyme ;
carbamyl phosphate synthetase deficiency
galactoseamia is due to deficiency of
Galactose-1-Phosphate Uridyl transferase
GM1 gangliosidosis is due to deficiency of what enzyme ?
B-galactosidase
Tay Sach’s disease (GM2 Gangliosidosis) is due to deficiency of what enzyme ?
hexosaminidase
Niemann Pick disease is due to deficiency of what enzyme ?
sphingomyelinase
Gaucher’s disease is due to deficiency of
glucosylceramidase
in Mendelian disorders the primary fault is in what?
the structure of the gene
what enzyme is deficient in Lesch Nyan syndrome ?
hypoxanthine-guanine phosphoribosyl transferase (HPRT)
examples of autosomal dominant IEM
1) variegate porphyria
2) familial hypercholesterolaemia
albinism is caused by deficiency of
tyrosinase in melanocytes
Fabry’s disease is deficiency of
alpha-D-galactosidase enzyme
