Term
| Maple syrup urine disease is a disorder of ____ metabolism. |
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Definition
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Term
| What is the inheritance of PKU? |
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Definition
|
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Term
| What enzyme is defective in PKU? |
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Definition
| phenylalanine hydroxylase (can't convert Phenylalanine into tyrosine) |
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Term
| What causes the symptoms of PKU? |
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Definition
| phenylalanine accumulation causes brain damage, tyrosine deficiency leads to deficient levels of neurotransmitters; elevated phenylalnine interferes with tyrosinase leading to hypopigmentation |
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Term
| T/F The phenylalanine restricted diet is recommended for the entire lifetime of patient's with PKU. |
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Definition
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Term
| Maternal PKU can cause what kind of abnormalities in the fetus? |
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Definition
| microcephaly and congenital heart disease |
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Term
| When does a mother with PKU need to start controlling her Phe levels during pregnancy? |
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Definition
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Term
| What labs can be used to diagnose PKU? |
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Definition
| elevated plasma Phe, elevated Phe/Tyr ratio, normal biopterin studies, DNA testing |
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Term
| What is the cofactor needed to convert Phe into Tyr? |
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Definition
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Term
| What is the purpose of tyrosinase? |
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Definition
| converts tyrosine into dopaquinone which is a precursor to melanin |
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Term
| In what cells is tyrosinase located? |
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Definition
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Term
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Definition
| heterogenous causes; tyrosinase deficiency, P-gene, melanosomal defects, etc. |
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Term
| What is the deficiency of tyrosinemia type 1? |
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Definition
| fumaroacetoacetic acid hydrolase deficiency |
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Term
| What is the deficiency in tyrosinemia type 2? |
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Definition
| tyrosine aminotransferase |
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Term
| What are the symptoms of tyrosinemia type 1? |
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Definition
| kidney and liver disease, peripheral neuropathy, risk of liver cancer |
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Term
| What are the symptoms of tyrosinemia type II? |
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Definition
| skin rashes, corneal abnormalities, mental retardation |
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Term
| Homocysteinuria is a defect in ____metabolism |
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Definition
| methionine and homocystine (methyl donor cycle) |
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Term
| What deficiencies can mascarade as homocystinuria? |
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Definition
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Term
| What enzyme is deficient in homocystiene metabolism? |
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Definition
| cystathione synthase (homocystine to cystathione) |
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Term
| What is the relationship between methionine and homocysteine? |
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Definition
| homocysteine is methionine without a methyl group |
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Term
| What is the phenotype of homocystinuria? |
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Definition
| tall, seizures, mental retardation, dislocated lenses, malar flush, pectus excavatum, long arm span, long fingers, pes planus, genu valgum |
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Term
| What cofactor is needed for the conversion of homocystine to cystathionine? |
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Definition
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Term
| What is a common fatal complication of homocystinuria? |
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Definition
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Term
| What is the difference between Marfan's and homocysteinuria? |
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Definition
| marfans is AD, has a normal IQ, and cardiovascular abnormalities are the main cause of mortality; homocystinuria is AR, assoc with mental retardation and causes thrombotic problems |
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Term
| What is the defect in maple syrup urine disease? |
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Definition
| branched chain amino acid catabolism (leucine, isoleucine, valine) via branched chain ketoacid dehydrogenase |
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Term
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Definition
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Term
| What are the symptoms of MSUD? |
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Definition
| maple syrup odor and metabolic ketoacidosis |
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Term
| What product builds up in MSUD? |
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Definition
| alpha-keto beta methylbutyric acid |
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Term
| What is the deficiency in nonketotic hyperglycinemia? |
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Definition
| defect in glycine breakdown into NH3 and CO2 |
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Term
| What are the symptoms of nonketotic hyperglycinemia? |
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Definition
| symptoms within first 24 hours of hypotonia/encephalopathy; seizures, burst suppression on EEG |
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Term
| What are the lab findings of nonketotic hyperglycinemia? |
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Definition
| increased CSF/plasma glycine |
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Term
| How do you treat nonketotic hyperglycinemia? |
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Definition
| benzoate, dextramethorphan |
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Term
| What is the prognosis of nonketotic hyperglycinemia? |
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Definition
| poor; diet is ineffective |
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Term
| What is the purpose of the urea cycle? |
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Definition
| excretion of waste nitrogen and arginine syntehsis |
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|
Term
| How many nitrogens are gotten rid of with one turn of the urea cycle? |
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Definition
|
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Term
| What are the prenatal warning signs of urea cycle disorder? |
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Definition
|
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Term
| What are the symptoms of urea cycle disorder? |
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Definition
| irritability and feeding problems with labored breathing |
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Term
| What are the positive labs for urea cycle disorder? |
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Definition
| respiratory alkalosis and hyperammonemia |
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Term
| What is abnormal about the plasma amino acids in ornithine transcarbamylase deficiency? |
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Definition
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Term
| What is abnormal about the plasma amino acids in ornithine transcarbamylase deficiency? |
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Definition
|
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Term
| What is significant about the urine organic acids in ornithine transcarbamylase deficiency? |
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Definition
| marked elevation of orotic acid (carbamoyl phophate builds up and pyrimidine synthesis converts it into orotic acid) |
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Term
| Which urea cycle disorder is x-linked? |
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Definition
| ornithine transcarbamylase deficiency |
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Term
| Name the urea cycle disorders. |
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Definition
| ornithine transcarbamylase deficiency, carbamoyl phosphate synthase deficiency, N-acetylglutamate syntehase def, arginase def, citrullinemia, argininosuccinic acidiuria, |
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Term
| A female with a carbamoyl pohsphate deficiency on one of her x chromosomes might have symptoms of.. |
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Definition
| ataxia, bizarre behavior, and protein avoidance |
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Term
| Why are females carriers with OTC def symptomatic? |
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Definition
| skewing of X-inactivation (unfavorable lyonization) |
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Term
| How do you diagnose urea cycle disease with labs? |
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Definition
| hyperammonemia, respiratory alkalosis initially; then confirm with pattern of decreased or elevated urea cycle compounds on the plasma amino acid analysis and whether or not orotic acid is elevated |
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Term
|
Definition
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Term
| How do you treat urea cycle disease? |
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Definition
| low protein diet and medications to control ammonia levels; hemodialysis for severe elevations of ammonia; liver transplant |
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Term
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Definition
| intermediates in the catabolism of amino acids, lipids and other compounds |
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Term
| What are organic acidemias? |
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Definition
| diseases due to defects in the conversion of intermediates into kreb cycle components |
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Term
| What are the laboratory presentations of organic acidemias? |
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Definition
| metabolic acidosis (low bicarbonate), increased anion gap, ketosis, +/- elevated ammonia level, secondary carnitine deficiency |
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Term
| What is the defect of propionic acidemia? |
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Definition
| can't make propionyl CoA into methylmalonyl CoA |
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Term
| What is the cofactor for the conversion of propionyl CoA into methylamlonyl CoA? |
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Definition
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Term
| What is the defect of methylmalonic acidemia? |
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Definition
| can't convert methylmalonyl CoA into succinyl CoA |
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Term
| What is the cofactor needed for the conversion of methylmalonyl CoA into succinyl CoA? |
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Definition
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Term
| What is the defect of isovaleric acidemia? |
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Definition
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Term
| What is the edeficiency of glutaric acidemia? |
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Definition
| can't convert glutaryl CoA into crotonyl CoA |
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Term
| What is the treatment of propionic acidemia? |
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Definition
| stat hemodialysis, glucose and carnitine |
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Term
| What is the prognosis of propionic acidemia? |
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Definition
| normalization of mental status and tone after mergency treatment and specialized diet; may have mild motor and language delay |
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Term
| In patients with propionic acidemia it is important to have them on a diet supplemented with what nutrients? |
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Definition
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Term
| How is methylmalonic acidemia treated? |
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Definition
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Term
| What are the two types of methylmalonic acidemia? |
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Definition
| B12 responsive versus non-B12 responsive |
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Term
| Name some possible causes of B12 deficiency? |
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Definition
| gastric surgery, pernicious anemia, strict vegetarianism |
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Term
| B12 deficiency can look like what kinds of inborn errors of metabolism? |
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Definition
| either methylmalonic acidemia or homocystenuria |
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Term
| What are the symptoms/labs of glutaric acidemia type I? |
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Definition
| neurological deterioration, dystonia/choreoathetosis, metabolic acidosis with wide anion gap |
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Term
| What is the deficiency in glutaric acidemia type I? |
|
Definition
| can't convert glutaryl CoA into crotonyl CoA |
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|
Term
| How do you treat glutaric acidemia type I? |
|
Definition
| diet, carnitine, riboflavin |
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|
Term
| What is the cofactor associated with propionic acidemia? |
|
Definition
|
|
Term
| What is the cofactor associated with methylmalonic acidemia? |
|
Definition
|
|
Term
| What is the cofactor associated with isovaleric acidemia? |
|
Definition
|
|
Term
| What is the cofactor associated with glutaric acidemia? |
|
Definition
|
|
Term
| What is the cofactor associated with MSUD? |
|
Definition
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|
Term
| What is a feature unique to isovaleric acidemia? |
|
Definition
| sweaty foot odor to urine |
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|
Term
| What symptoms are specific to glutaric acidemia? |
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Definition
| macrocephaly, dystonia, abnormal MRI |
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Term
| What is the difference between urea cycle diseases versus organic acidemias? |
|
Definition
| urea cycle disease is associated with respiratory alkalosis and OA is associated with ketoacidosis |
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Term
| T/F Hyperammonemia is a good way to tell urea cycle disease from organic acidemias. |
|
Definition
| false; you can have hyperammonemia in OA |
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|
Term
| What is the typical presentation for medium chain AcylCoA dehydrogenase deficiency? |
|
Definition
| viral illness -> poor appetite -> listless -> hypoketotic hypoglycemia |
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Term
| What is the mortality rate of the first episode of hypoketotic hypoglycemia in MCAD deficiency? |
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Definition
|
|
Term
| What is the most common fatty acid oxidation disorder? |
|
Definition
|
|
Term
| Can MCAD def be diagnosed at birth? |
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Definition
| yes; they are asymptomatic but you can identify them by NBS |
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|
Term
| What are the symptoms of defects in long chain fatty acid metabolism? |
|
Definition
| hypoketotic hypoglycemia, cardiomyopathy, failure to thrive, and hypotonia, myopathy, liver disease |
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Term
| How do you treat long chain 3-OH acyl CoA dehydrogenase deficiency? |
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Definition
| improvement after dietary treatment |
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|
Term
| What does LCHAD deficiency stand for? |
|
Definition
| long chain 3-OH Acyl CoA dehydrogenase deficiency |
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|
Term
| What lab is used to diagnose fatty acid oxidation disorders? |
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Definition
|
|
Term
| What is the typical psesntation of SCAD? |
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Definition
|
|
Term
| What are the symptoms of VLCAD def? |
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Definition
| variable: hypoketotic hypoglycemia, hypertrophic cardiomyopathy, myopathy, liver disease |
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|
Term
| When is the typical onset of VLCAD? |
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Definition
| extremely variable, ranging from neonatal to adult onset |
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Term
| Which fatty acid oxidation disorder requires a low fat diet? |
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Definition
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|
Term
| How do you treat fatty acid oxidation disorders? |
|
Definition
| avoidance of fasting; some patients need carnitine and corn starch supplements and low fat diet |
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Term
| Name three diseases of galactose metabolism. |
|
Definition
| galactokinase deficiency, galactose-1-phosphate uridyltransferase, epimerase deficiency |
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Term
| What is the deficiency of classical galactosemia? how is it inherited? |
|
Definition
| galactose-1-phosphate uridyltransferase deficiency; autosomal recessive |
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|
Term
| What are the symptoms of galactose-1-phosphate uridyltransferase deficiency? |
|
Definition
| vomiting, diarrhea, lethargy, liver disease, jaundice, renal tubular disease, cateracts, E.coli sepsis |
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|
Term
| How do you diagnose classical galactosemia? |
|
Definition
| urine reducing substances are suggestive; enzyme assay confirms; can also use DNA testing |
|
|
Term
| How is classical galactosemia treated? |
|
Definition
|
|
Term
| What are the long term sequelae of classical galactosemia? |
|
Definition
| can be treated with galactose free diet but may still have developmental delay, ataxia, and ovarian failure |
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|
Term
| Galactokinase deficiency is associated with what delterious effects? |
|
Definition
|
|
Term
| What are the symptoms of epimerase deficiency? |
|
Definition
|
|
Term
| What are the symptoms of hereditary fructose intolerance? |
|
Definition
| liver and kidney damage, hypoglycemia, vomiting, lethargy, coma |
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|
Term
| How do you treat hereditary fructose intolerance? |
|
Definition
|
|
Term
| Which inborn error of metabolism can cause the patient have a lack of dental caries? |
|
Definition
| hereditary fructose intolerance |
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