I did an AMA a while back, and others have done them as well. Today is PKU Awareness Day, so in case anyone out there is still curious, AMA.

The rundown: PKU is a hereditary metabolic disorder in which the liver doesn't produce enough of the enzymes that break down the essential amino acid phenylalanine ("phe" for short.) Phenylalanine would normally be processed into tyrosine, but for individuals with PKU, the enzyme activity is completely nonexistent or diminished, and the increased levels of phe become toxic to the central nervous system. Treatment involves a very restricted diet, and a prescribed medical food that contains all the amino acids except phenylalanine. It is now accepted that treatment must be maintained for life; although in the past, patients were told to stop treatment during adolescence. Phenylalanine is the main component of the artificial sweetener aspartame, hence the phenylketonuric warnings on gum and diet sodas. It is also present in almost every food to some degree.

If you or someone you know has PKU and needs support, please visit one of the websites below and/or look up support groups online. There are a lot on facebook (just search for pku or phenylketonuria), and here we can be found at /r/phenylketonuria

http://www.npkua.org/ United States

http://www.canpku.org/ Canada

http://www.espku.org/ Europe

edit: I was verified by the mods in a previous post: http://www.reddit.com/r/IAmA/comments/1i4nz2/phenylketonurics_contains_phenylalanine_i_have/cb0xqjj

edited edit: That's "phenyLKetonurics" up top... I've typed it so many times today that I was bound to goober it up somewhere. Of course it's in the one place I can't fix it!

Comments: 72 • Responses: 28  • Date: 

DoNotForgetMe31 karma

Hi! My dad is a pediatrician who specializes in GEM (genetics, endocrinology, metabolism) and he has many patients with PKU under the age of 21. He has told me that sometimes it is a struggle to get his patients and their parents to be open with him about how they feel in terms of quality of care on his part and their resulting quality of life. As I am studying to be a doctor as well, I'm wondering: If you could say one thing to your doctors, or change one thing about they way they have treated you, what would it be?

mermaid-out-of-water12 karma

This is tough. My doctors are pretty awesome, but I know there are a lot of people who feel helpless to enact change in their lives and receive no help from their doctors aside from "lower your phe levels." There are a lot of people who simply don't know how to manage the daily minutiae of pku-related tasks. Unfortunately what they need is a life coach or in-home assistance to get started. People don't want to tell the doctor the truth about how they live for fear or judgment or reprimands.

This is a known and ongoing discussion in the PKU world. I think PKU clinics just need more support staff, cooking classes, meetups, and general support. I'm not sure what doctors can do differently aside from advocate for those support systems.

Does that answer your question at all? There are so many variables in PKU care.

DoNotForgetMe1 karma

Yes that is helpful. Something I will keep in mind in the future.
Thank you very much.

mermaid-out-of-water1 karma

Please feel free to look me up if you ever want further dialogue.

hopagopa9 karma

What sort of treatments are in development or already in use?

mermaid-out-of-water13 karma

The most widely followed treatment is a very restricted diet, and a prescription-only protein drink that provides the remaining amino acids we can't get from food.

We also have a drug called Kuvan that can stimulate enzyme activity in the liver, but it does not work for everyone.

There is currently an injectible drug in trial called PEG-PAL that should work on everyone with PKU.

Researchers are working on other treatments and a cure as well, but the ones I listed are the only ones used currently.

EverSoSlightlyObtuse8 karma

OP, how severe is your PKU? Also, did/do you ever attend any of the PKU get-togethers? (Summer camps and so forth?) And, has PKU effected your mental acuity, general development, formal learning? My sister, who strictly adheres to her diet, has severe ADD which doctors have said was exacerbated by her PKU.

mermaid-out-of-water3 karma

I have one classic gene and one variant gene. Not totally sure about the scientific meaning behind that, but I do have a somewhat higher phe tolerance than someone with Classic PKU. Now that I'm taking Kuvan my tolerance has increased significantly. I'm one of the lucky ones.

I have attended many conferences and plan to continue in the future. Camp PHEver in Texas is one of my favorites. I attended from the beginning and still try to visit every year.

I'm not totally sure how much PKU directly affected my mental acuity and learning abilities. I managed to get through college just fine, never had any major issues. In hindsight I realize there were some times where I had a hard time getting or drinking my formula for assorted reasons and those probably coincided with drops in grades. I have some anxiety issues now, but no doctor has specifically linked the two. I honestly think the docs just don't know though. I can tell you my profession is administration, logistics, and organization. I don't know if those skills are heightened because of what it takes to manage PKU, or in spite of having PKU. Sometimes I think I just learned good coping skills. :/

EverSoSlightlyObtuse1 karma

Check out David & Goliath by Malcolm Gladwell. "Disadvantages" can be advantages! I attended a few camps in VA with my sister, but I'd have to ask her the name. She has "classic", very severe case of PKU. What foods w/ minimal amounts of protein are you able to eat?

mermaid-out-of-water3 karma

Before I started taking kuvan I was all veggies and potatoes, all the time. My fridge looked like a rabbit den - lettuce and carrots forever.

Things are a little different now. I don't have to special-order bread and pasta anymore.

flyingtulipss7 karma

Other than the altered diet, are you able to lead a typical life?

mermaid-out-of-water9 karma

Yes. At 32, I only really think about it while I'm mixing up my shake or dealing with the extra insurance kerfuffles. It makes travel a little tricky but I've definitely learned to plan ahead and be organized. Dining restrictions are more difficult with children with PKU who don't really understand what's happening yet, but at my age it's just part of the routine.

Edit to say: experiences really vary. I'm lucky to have great health insurance and a supportive family. Some people do find the treatment difficult. Finding resources on a limited income or without support from family and friends can be very frustrating.

mycakeday7 karma

I also have pku. 33 yo male. Mods deleted my post on the last pku ama. I've been off my diet for 15 years and I'm fine. Am I abnormal or will I feel these affects at some point?

mermaid-out-of-water8 karma

It really depends on the severity of your PKU. Have you had your phe level checked lately? A lot of people can't tell a difference until their phe level goes down because off-diet feels normal to them after so long.

Common side effects of being off diet are depression, anxiety, and other neurological complications. Different people feel different things though.

mycakeday4 karma

Haven't had any real issues since I went off the diet around 18 years old. My hands have a slight shake. The doctors told me that could happen. I've never had my levels checked since going off of the diet.

mermaid-out-of-water5 karma

If you ever get curious, there are pku clinics all over the place who would probably be happy to help, even if just to see where you're at.

AphiTrickNet4 karma

What would be the side affects if you were to eat some?

mermaid-out-of-water5 karma

Nothing right away, and effects vary by person, but if I overdo it on one meal then two days later I feel physically uncomfortable, irritable, and have a hard time paying attention to anything. Over time there are a whole slew of neurological complications that can occur.

Bignick692 karma

Have you ever experienced toxic phe levels?

mermaid-out-of-water1 karma

When I was a rebellious teenager I scored a level of 15 once and that was pretty awful. For me and probably anyone around me. I get fussy and feel like everyone is attacking me.

To my knowledge my level has never surpassed my diagnosis level of 18. I'm lucky - others are far more sensitive.

crypto493 karma

What are the end-effects of PKU which affect your day to day life?

mermaid-out-of-water4 karma

I make different decisions regarding food and constantly worry about the state of my health insurance and finances. I've thankfully been receiving treatment my entire life, so do not experience the same complications as someone who has had to go without treatment for an extended period of time. And I drink my pku shake three times/day without fail or I feel pretty terrible.

Nothing_Doing3 karma

What is something the average person can do to A. Raise awareness and B. Help find a cure? Are there fund raising groups like Koman has for cancer?

mermaid-out-of-water4 karma

National organization websites are probably the best place to start.

http://www.npkua.org/ United States

http://www.canpku.org/ Canada

http://www.espku.org/ Europe

At least in the US, the NPKUA is always calling for volunteers to contact legislators to ask them to support things like the Medical Foods Equity Act and recently, to re-authorize federal programs that work on Newborn Screening. On a smaller level, one could always select a PKU organization on smile.amazon.com while shopping.

Today is the US's nationally recognized PKU Awareness Day, and the month of May is our awareness month. Other countries have different days, and Rare Diseases day is February 28. We share a lot of our stories on social media at these times to raise awareness. #pkuawareness :)

Thank you for that great question!



mermaid-out-of-water3 karma

Spirits are free of protein, wine is lower in protein, and beer (especially dark beer) tends to have a bit too much for the average PKU person to tangle with.

PKarnes2 karma

Do you have pale skin?

mermaid-out-of-water5 karma

I've seen folks with PKU in all colors, and it is found all over the world. Not everyone with PKU has blond hair/blue eyes/pale skin. I do, but it runs in my family. :)

Lack of treatment can cause loss of pigmentation though. Many adults who went off diet as a teenager and returned as an adult were blond as teenagers and now have a different hair color.

PKarnes2 karma

Do you take tyrosine supplements?

mermaid-out-of-water3 karma

I do not. Thankfully my tyrosine levels have always been where they're supposed to be.

PKarnes2 karma

Which type of PKU do you have?

mermaid-out-of-water2 karma

Variant PKU I suppose? Somewhere between Hyperphe and classic PKU. I have one classic gene and one variant. My doc seems to prefer to simply treat the individual and doesn't really focus on type I guess.

hopagopa2 karma

What's your favorite song?

mermaid-out-of-water3 karma

A really tough question! I love pretty much anything I can belt out in my car (Adele's Skyfall, Britney Spears' Mannequin, Norah Jones, Nicole Atkins). I also have a soft spot for Ain't No Mountain High Enough thanks to PKU camp. I like a lot of songs. Can't pick one favorite.

plasticblue942 karma

How is PKU normally caught in children? Do they typically have brain or other damage before it gets caught?

mermaid-out-of-water3 karma

PKU is detected through Newborn Screening. If it is missed or the place the baby is born doesn't offer it, it can take 18 months to be diagnosed through lack of reaching developmental milestones. In late diagnosed cases, there is almost always permanent damage.

Here's a link to a newborn screening info site if you want to know more: http://www.babysfirsttest.org/

octopus56502 karma

What is the worst thing that happened from eating too much protein?

mermaid-out-of-water2 karma

For me personally? A string of really bad days and possible loss of a few brain cells.

Others have suffered seizures, tremors, prolonged neurological issues, and headaches. There are varying degrees of PKU.

octopus56501 karma

Wow, that's a lot. Glad you don't get seizures. So meat is totally out of the question, right?

mermaid-out-of-water1 karma

Before I started taking the new drug that activates some enzyme activity, meat was totally off the table. Now I take a taste on occasion.

ZippityBoop2 karma

If you could have any food/drink without having to worry about the consequences, what would it be?

mermaid-out-of-water2 karma

Hmmm... edamame, escargot, coffee drinks with milk, Greek yogurt, salmon...

nlow922 karma

How do you prepare to eat out at a restaurant or a friend's house who doesn't know much about the diet?

mermaid-out-of-water2 karma

For restaurants I check to see if there's a menu online or research the type of cuisine and what I can eat from it. For unfamiliar friends I just ask what the food situation will be and usually offer to bring something. Luckily I've never encountered anyone who responded with hostility toward my dietary restrictions, but I've also never flat-out told anyone they HAVE to cater to my needs.

Some people with PKU take their own low-protein (special order) pasta or bread into a restaurant and ask them to heat it up/add sauce. I like to be adventurous and challenge myself to find something the restaurant already serves that I can eat. Lots of salads and fries when I was younger and less willing to try new things, but now I'm generally able to find something decent anywhere.

EverSoSlightlyObtuse2 karma

Have you had children? Or planning to? If so, have you or would you check to see if your husband/partner was a PKU carrier?

mermaid-out-of-water2 karma

No kids yet, thinking about it for next year though. Getting to be about that time. My husband and I are looking into testing options. He very valiantly says he just wants a kid with me, regardless whether it has PKU or not, but I'm way more cautious and want to know our actual probability. :)

EverSoSlightlyObtuse3 karma

Absolutely! Your husband sounds great. When my sister was pregnant, the doctors actually had her eating some protein! My nephew (PKU free) was able to metabolize it for her in utero. It was really cool. She became a hopeless cheese addict during those 9 months. She got to eat ice cream, too. Mac n' cheese was her favorite, though! (And mine, too! Was able to share my favorite food with her for the first time!)

mermaid-out-of-water1 karma

He is. :)

Mac and cheese is definitely problematic. :) When I first started taking kuvan and we were testing my limits I ate so much cheese. I'm in control now though. ;)

WombatNewsNetwork1 karma


mermaid-out-of-water3 karma

I have not personally heard of any cases diagnosed during adulthood, but at least in Texas the test itself is supposedly only $17ish. If you get in contact with a local PKU clinic and are super polite and nice they might find a way to do the test/exam just to set your mind at ease. I can't make any promises though.

That said, you're not the only person who has had a similar reaction to aspartame. I can't offer any medical advice, but ouch to those headaches! Just avoid it like the plague! Hope you can find medical peace of mind soon.


I know aspartame is unhealthy, even for those of us without PKU; can you explain why it is unhealthy for the gen pop?

StumbleOn8 karma

Kind of a loaded question. Science is pretty clear that it is not bad for you.


I disagree. It crosses the BBB: blood brain barrier. It should have never been introduced as a food product.

The FDA messed up on this one.

Thallassa3 karma

So does glucose. Are you saying that we shouldn't have glucose?


Glucose is natural.

Aspartame is man made.

I give up. You kids are insufferable

Thallassa3 karma

I'm a graduate student in biochemistry, not an insufferable kid.

There's nothing innately different between a man-made and a natural compound. Natural compounds have billions of effects in the body that we don't understand. Man-made compounds do too. We know glucose is safe because people have been eating it for thousands of years with no harmful effects. We think aspartame is safe because people have been eating it for 20 years with no harmful effects, but the only way to know for sure is to let people keep eating it for another couple hundred years or so and track the results. (I mean, preferably with a control group that doesn't eat aspartame but is otherwise statistically identical).

However, from our (limited) knowledge of the human body, we can predict what effects any compound would have in the brain, in the liver, and in other parts of the body. Unfortunately this is ridiculously complex, especially as we don't know what all the parts are. No one's found any piece of the brain puzzle that interacts with aspartame. They have found correlations between aspartame consumption in rats and undesirable effects in the brain. Other studies conducted similarly have not found these correlations. So the jury is still out on that.

mermaid-out-of-water1 karma

Thank you for taking the time to explain that.

mermaid-out-of-water7 karma

Anything I could offer on that subject would be purely personal opinion, and certainly not definitive or relevant. I would be happy to attempt to answer a question about PKU though.


How has PKU affected you?

mermaid-out-of-water3 karma

In daily life, I drink my protein in the form of a prescription powdered drink mix and have a restricted diet of mostly vegetables and some starches. Luckily I'm a responder to the one drug available to help treat PKU, so I also take 19 pills a day. I also spend a lot of time worrying about treatment costs and health insurance. Every month I have to stab my finger to collect a few drops of blood to check phenylalanine levels in my blood. On the brighter side, I've gotten to meet a ton of really great people with PKU from all over the world. I also have developed strong personal responsibility and organizations skills. There's a lot of math and planning involved.