|
Serum phenylalanine screening How the Test is Performed:
Infant:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. Three drops of blood are placed in three separate test circles on a piece of paper. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding .
The test paper is taken to the laboratory where it is mixed with a type of bacteria that needs phenylalanine to grow, and another substance that inhibits phenylalanine from reacting with anything else.
How to Prepare:
Infants and children:
For the physical and psychological preparation you can provide for your child, see the following topic:
How it Feels:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing .
Risks:
Risks associated with venipuncture are slight: - excessive bleeding
- fainting or feeling lightheaded
- hematoma (blood accumulating under the skin)
- infection (a slight risk any time the skin is broken)
- multiple punctures to locate veins
Why this Test is Performed:
This test is performed on infants to screen for PKU . If the defect is detected early, the severe side effects may be avoided through diet modification.
Normal Values:
A normal test results in no bacteria growth. This indicates that there was enough phenylalanine inhibitor to prevent the bacteria from using the phenylalanine and growing.
Abnormal Results:
Bacteria growth indicates that there was not enough phenylalanine inhibitor to prevent the bacteria from using the phenylalanine and growing. PKU is a possibility and further testing will be performed.
Cost:
Information not available.
Special Considerations:
Not applicable.
|
