BCHM 10000 Lecture Notes - Lecture 3: Mass Spectrometry, Zygosity, Tetrahydrobiopterin
3 Jul 2018
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Department
Course
Professor
PKU
• Discovery
– Phenylketonuria (PKU) first described first in 1934 by Ivar Asbjørn Følling
• Symptoms
– Name of disease gives clear indication of disease symptoms
– Phenylalanine (phe) and phenylpyruvate accumulate in the blood
●Normal blood phenylalanine levels are around 60 μM
●In untreated PKU they can be as high as 2.4 mM (40x higher)
– Phenylpyruvate accumulates in the urine
– Musty odor due to presence of phenylacetate in bodily fluids
Symptoms (cont’d)
PKU
– Seizures soon after birth if undiagnosed
– Mild albinism
– Brain damage and mental retardation if left untreated
– Widely recognized inborn error of metabolism because of warning labels on diet drinks
containing aspartame
Diagnosis
– Elevated levels of phe can be detected in blood
– Guthrie test reports on bacterial growth made possible in the presence of the toxic
phenylalanine analog 2-thienylalanine by the elevated levels of phe in blood sample
Document Summary
Phenylketonuria (pku) first described first in 1934 by ivar asbj rn f lling: symptoms. Name of disease gives clear indication of disease symptoms. Phenylalanine (phe) and phenylpyruvate accumulate in the blood. Normal blood phenylalanine levels are around 60 m. In untreated pku they can be as high as 2. 4 mm (40x higher) Musty odor due to presence of phenylacetate in bodily fluids. Brain damage and mental retardation if left untreated. Widely recognized inborn error of metabolism because of warning labels on diet drinks containing aspartame. Guthrie test reports on bacterial growth made possible in the presence of the toxic phenylalanine analog 2-thienylalanine by the elevated levels of phe in blood sample. 2-thienylalanine competes with endogenous phe, is incorporated into proteins and kills cells. Exogenous phe (from the blood sample) outcompetes the 2- thienylalanine and allows the cells to grow. Elevated levels of phe can be detected in blood. Only two states require parental consent for pku testing.
