Term
| Maple Syrup Urine Disease |
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Definition
The disease is due to a deficiency in branched-chain alpha-keto acid dehydrogenase (BCKAD). Autosomal recessive.
Diagnosis:
Levels of branched-chain alpha-amino acids and their alpha-keto analogs are elevated in plasma and urine.
Can also use C14 labeled branched chain amino acids, and measure the 14CO2 release rate.
Neurological problems are common. High mortality.
Treatment:
Involves a restricted dietary intake of the branched chain amino acids. |
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Term
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Definition
A rare, autosomal recessive disorder caused by a deficiency of the enzyme homogenisic acid oxidase, normally involved in the breakdown of tyrosine to fumarate.
Leads to an accumulation of homogentisate, which polymerizes to produce a black-brown pigment that is deposited in cartilage and other CT. Ochronosis.
Features:
Joint damage/arthritis, brown-black urine (on standing), black sweat (rare).
No specific treatment. |
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Term
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Definition
Deficient of the enzyme tyrosinase which converts tyrosine to melanin.
Patients with this disease have white hair, pale skin and grey-blue eyes. Constant frowning.
Treatment includes tinted contact lenses and high sun protection. |
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Term
| Type I hyperphenylalaninamemia (Phenylketonuria) |
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Definition
Deficient or absent phenylalanine hydroxylase. This causes a buildup of phenylalanine in the blood which can cause severe mental retardation. These patients tend to be fair-haired, blue eyed and pale since phenylalanine inhibits tyrosinase which converts tyrosine to melanin.
Treatment includes a diet low in phenylalanine. Must be instituted very early; neonatal screening is a must. |
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Term
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Definition
Hyperphenylalaninaemia which can cause severe problems in a fetus. Almost 100% of children with mothers who had serum PHE levels of more than 20mg/dl were mentally retarded.
Requires stringent phenylalanine control! |
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Term
A patient's bloodwork results are given to you and you notice elevated creatine kinase levels. When seeing this, you immediately order another lab test on the blood targeting a specific isoenzyme of CK. The results of the second test also show that 4% of the total CK in the bloodwork is this isoenzyme.
What is the name of this second enzyme and what does this indicate in this patient? |
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Definition
| Creatine Kinase II (CK-MB), this indicates a relatively recent (past 24 hours) myocardial infarction. 3-4% of isoenzymes in blood is high! |
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