Untreated PKU – What’s the Worst that Could Happen?

You tend to hear from everybody in the PKU world that it’s super important to stay on diet, and the thought of going rogue is something that’s rather quickly dismissed as any bit of a possibility whatsoever. But why? There are people alive today that had been born before newborn PKU screening was a reality, and spent most of their lives not even knowing that they had the condition. Can untreated PKU really be that scary? It may seem tempting when looked at in that light to abandon the diet, and start living without having to worry about such a large lifestyle change — but that’s an awful idea.

Here are a few reasons why.

Physical impairments to development are a common result of untreated PKU

Many of the aforementioned people that are still around today that have been diagnosed with PKU later in their lives carry with them characteristics that had been wrongly associated with other disorders or development issues. The inability to properly digest phenylalanine can ultimately result in a slower growth rate for those that go untreated, or stunted growth altogether for those that go untreated during their youth. This symptom can be seen as well in the cases of microcephaly (a smaller head size) that are prevalent in cases where PKU has gone untreated.

Because the body cannot get rid of this phenylalanine efficiently on its own it can build up  to create a plethora of other resulting side effects. Another common physical trait of such is a musty odor that can be found within the person’s urine, breath, or skin that happens as a direct result of the body’s excess phenylalanine that has nowhere to go.

Seeing as phe plays a role in the body’s production of melanin, which is the pigment responsible for skin and hair color, it’s quite normal to find people with the condition bearing lighter skin, hair, and even eyes as a result of it. This impact on the skin can go a step further however in also potentially resulting in a predisposition to skin disorders like eczema, and a sensitivity to sunlight.

Mental development impairments can happen too

As scary as it is to consider effects beyond simply the physical, untreated PKU can also result in mental development impairments. Children in particular that are left untreated at a young age run an increased risk of developmental retardation that in many cases shows itself to be obvious by several months of age. Developmental delays in this regard may be difficult to deal with, but in many cases can be combated by seeking treatment at an early age.

These mental impairments occur essentially as a direct result of phenylalanine buildup in the bloodstream preventing the formation of myelin, which is a conductor-like material that helps to surround the neurons in the brain. An absence of myelin acts to slow down the brain signals which results in some of the standard slower-functioning results such as a lower IQ, chronic depression, anxiety, and mood swings.


Many of the aforementioned characteristics are things that adults that deviate from the diet report occurring, particularly depression, anxiety, and mood swings. Many adults claim that as you slowly bring the diet to a stop a sort of mental fog seems to take over, one that acts as a mask to the changes in mood. Things seem harder to understand, normal activities seem to take so much more focus than they used to, and maintaining a consistent mood becomes something of a challenge.

That’s terrifying. We all want to be in control of our mental state, and the thought of slowly having that deteriorate, often without much warning or notice to ourselves, is equally scary. Thankfully in many of these cases those that reported these symptoms also reported that they began to disappear again once the diet was returned to and their bodies’ phe levels were brought back to their normal ranges.

What if the balance is out of whack?

Treating PKU isn’t by any means a once-and-done thing. Phe levels need to be constantly monitored and kept track of, as there are numerous repercussions that can happen as a result of being either too high or too low.

In the event that phenylalanine intake is limited too severely the risk for developing a vitamin B-12 deficiency begins to skyrocket. B-12 deficiencies can have numerous symptoms such as low iron levels in the blood, fatigue, severe loss of appetite, and sometimes aggressive behavior. This is where the importance of formula comes in when it comes to treating PKU.

On the other hand, high levels of phenylalanine can result in some of the symptoms mentioned above such as mental fog, mood changes, depression, and anxiety. High levels of phenylalanine can also result in more serious mental changes such as erratic or aggressive behavior, destructiveness, and self-injury.

The gist: please, don’t let your PKU go untreated

If the severity of untreated PKU hasn’t quite been established to a high enough degree, feel free to take a look at this study that reported more symptoms associated with failing to treat the condition. Many of these effects are serious, but in the grand scheme of things are also entirely avoidable. It bears repeating that many people don’t notice the onset of many of these symptoms; deviating from the diet is hardly worth dealing with that moment of realization that occurs when the dangerous side effects begin to make themselves evident to you.

It’s hard. We get it.

That’s why we’re here to help.

To learn more about the effects of untreated PKU, give this brief documentary a watch.

Related Posts Plugin for WordPress, Blogger...
Posted in PKU

Leave a Reply

Your email address will not be published. Required fields are marked *


CommentLuv badge