Q PKU

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Q PKU

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vallia
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04/30/06 - 10:07 AM

A 20 year old female who is 2 months pregnant remembers that she had PKU as a child and required special diet. Tests confirm marKedly elevated maternal serum levels of phenylalanine and phenylacetic acid. Genetic tests have not been performed on the father. What should the physician tell the parents regarding the welfare of the child.

A. childhood phenylalanine restriction is sufficient to protect the health of the child

B. further information is required to ascertain if the fetus is at risk

C. the fetus is at no risk if it is heterozigous for the PKU gene

D. the fetus is at no health risk if phenylalanine levels are normalized by the third trimester

E. the mother's hyperphenylalaninemia may have already harmed the fetus

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star1
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04/30/06 - 11:10 AM

general malaise
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04/30/06 - 11:23 AM

E

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robin082006
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04/30/06 - 12:25 PM

E is correct

But what wrong with the choice C?

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mjl1717
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04/30/06 - 02:40 PM

PKU is preventable, occurs FAST, this why we have early prenatal screening in most states, tyrosine becomes essential, one way to Dx is with the Guthrie test. Autosomal reccssive. The mental retardation can occur quickly.

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vallia
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04/30/06 - 11:36 PM

it's E

even if the child is heterozigous he will develop PKU at high concentration of maternal phenylalanine. Fetal alanine hydroxylase cannot compensate the high maternal levels of phenylalanine. the critic period is from week 3 to week 8 so by the end of 2'nd month of pregnancy the damage has already occurred

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