A Day in the Life with PKU: Blood Draws

A vital part of managing the PKU diet treatment is testing the blood to find out phenylalanine levels.  According to our clinic at UAB, the acceptable normal range for blood phe is between 2 and 6 (don't ask me to get technical, let's just look at the numbers! lol).  The first blood draw, through the Newborn Screening Program, done in the hospital after Carson was born, the level was 5.8.  For a newborn, that raises a red flag.  I believe it should have been closer to 1 (I think Maggie's was either 1 or lower when she was born, and she does not have PKU).  We got the call from our pediatrician about that level about a week after Carson was born.  The very next day, we were told to take him to Children's Hospital for more blood work.  The doctor even said it might have just been a fluke because it was so rare.  When the results came back from Children's, we were told to go to the genetics clinic at UAB.  Carson's blood phe level was 29!  He was indeed diagnosed with classic PKU at 10 days old.

From that day forward, we began this journey of diet plans and phe calculations and blood work.  I was still working full time when Carson was a baby, so I decided to take him to the doctor's office for the first months of his life and let them draw his blood for me.  It was free and they did all the work!  I am so glad I let them prick his heel every week; thankful I did not have to do it.  Whenever he was around 1 year old, really before, because he was so big and his heels got so thick, they said it was time to stick his finger.  After our genetics clinic visit, I got a prescription for lancets and got brave enough to start pricking Carson's finger at home.  He does great and I have no problem with him!  Unfortunately, I am not the world' greatest nurse, and sometimes I don't hit the right spot for good blood flow and have to stick him a few times.  That part is not fun.  But Carson is such a big boy and doesn't put up a fuss!

The process is different from that of a diabetic testing their sugar.  At this time we only have to do a finger stick every 2 weeks.  Unfortunately, an at-home test for phe levels for PKU has not yet been perfected, so we have to put the blood on a lab slip, the same lab slip used in the hospital for newborns (our clinic provides these to us), and then we mail it to the State Department of Health.  They process the blood and notify UAB genetics clinic with the results.  The dietician from the clinic in turn calls me to report the numbers.  Carson's last level was 4.9, I think, which is considered in normal range, but I feel his behavior is better when it is lower.  I just mailed another sample last week, but since today is a State holiday (yes, it is Jefferson Davis's Birthday) I probably will not hear the results until tomorrow, I hope.  If his level comes back over 6, then the nutritionist instructs us to do what is called a washout, where we feed Carson as little phe as we can for a day or two, then go back to normal diet for a few days and send another blood sample to see if it came down.  I can usually tell if Carson's blood phe level is high, because it makes him sleepier and crankier.  His behavior seems to be better when his phe is in the lower range.  Usually the only times it has been high was when he was younger and teething, or now especially when he is sick.  Fighting off infections or viruses causes a change in metabolism, which in turn affects the way his body processes and rids itself of phe.


This is Carson's blood drawing kit.  I keep cotton, Band-Aids, lancets,
and the lab slips all in one place to make it quick and easy.  I did not
get a picture of the actual act because I did this one while he was asleep!
If you notice the lab slip above, the blood has to drop in these
little circles on the special lab paper and then dry for several hours.
Then we mail it in the envelope provided.
Carson calls it "painting circles".  I am trying to teach him now that
we have to send it to the doctor to "count his phes".

We are so fortunate right now that Carson does so well with his diet.  He does sometimes ask for other foods and get curious, but he handles it very well.  I try to offer him a low protein alternative for everything.  If he asks for ice cream, for instance, I remind him he doesn't even like ice cream!  I have tried many different kinds of low protein ice cream, and he just won't eat them.  It is not the taste; I believe it is the cold he does not like due to his sensory perception issues (related to his autism).  I hope as he continues to grow he will learn all he needs to know about his diet and that he will handle it with strength and grace.  With his love for controlling situations and having routines, I think he is a great candidate for continuing a successful diet for life.