What happens if pku is left untreated

There currently is no cure for PKU, but the condition is controllable through proper diet and supplements. The PKU diet includes foods that are low in protein, such as fruits and vegetables, as well as low protein products made especially for people with PKU, such as low protein bread and pasta.

A special medical food that contains other amino acids but no phenylalanine is a critical part of the PKU diet. Some children with PKU who are on a diet may benefit from a medication form of BH4, called Kuvan, which can lower phenylalanine levels in the blood, and may allow a patient to eat more natural sources or protein. Your child might be prescribed Kuvan to determine if it will make the diet easier. PKU is present in almost all societies but is very rare among those of African-American heritage and certain Asian countries e.

Those of Irish heritage as well as those with Turkish background have the highest risk.. Before signs are apparent, however, the brain may already be damaged, so treatment needs to begin during the first weeks of life before this happens Symptoms of PKU can include:. If treatment is administered within the first few weeks after birth, there should be no symptoms if the diet that is prescribed is strictly followed.

Symptoms might develop if the patient stops following the diet. A: PKU is very serious if treatment is not started for within the first 2 to 3 weeks of life. Although symptoms may not be visible, exposure to high levels of phenylalanine after 2 to 3 weeks can have long lasting negative effects such as intellectual challenges. Untreated PKU can lead to intellectual disabilities. If PKU is treated right away and your child strictly follows the prescribed low-phenylalanine diet, your child should enjoy a normal quality of life.

A: If a woman with PKU is not following a strict low phenylalanine diet during pregnancy, her baby may suffer from intellectual disabilities, heart defects and a small head microcephaly , even though her baby may not inherit PKU. Women looking to become mothers should follow a low-phenylalanine diet beginning before pregnancy to prevent their baby from suffering from PKU in the mother.

A: The main treatment for PKU is following a strict diet that eliminates high protein food such as, meat and dairy products and introduces a special formula. We will work with you and your child to establish a diet he can be on for life. A: If your child follows the diet correctly to get all the nutrients he needs, there should not be any side effects. To investigate what these patients can teach us about the inter-individual differences in brain vulnerability to high plasma Phe between PKU patients, this study aimed to review published cases of late-diagnosed PKU patients without ID despite high plasma Phe concentrations.

This search was updated on 3rd of February and 8th of September Then, full-text articles of the selected references were retrieved and read independently by two authors DvV, AMJvW to assess whether the inclusion criteria were met. This combination of inclusion criteria was aimed to identify those PKU patients representing the one end of the phenotypic spectrum with regard to neurocognitive outcome in relation to plasma Phe levels in untreated PKU patients.

Studies not describing detailed information on an individual PKU patient were excluded. The reference lists of all full-read articles were reviewed to identify additional eligible studies. Selection of eligible articles, selection of articles to be included, and extraction of data from selected articles was performed independently by DvV and AMJvW.

Results of the reviewing process are outlined in Fig. Of all 59 reported cases Table 1 , most patients had been diagnosed because of a sibling with PKU, or because they had given birth to children with PKU or children suffering from the maternal PKU syndrome. In addition, ten cases were identified by screening programs at adulthood. Most of these screening programs were performed in women before or during pregnancy to identify those being at risk of bearing children suffering from the maternal PKU syndrome.

In eight cases, the reason for diagnosis was different or not reported cases 32 and Case 9 was diagnosed because of high neonatal plasma Phe concentrations in her child without any underlying enzymatic defect in the offspring, and case 18 was diagnosed by a survey performed in the hospital [ 13 ]. Other cases were diagnosed because of cerebral symptoms.

Case 2 presented at childhood with hyperactivity [ 14 , 15 ]. Cases 41 and 42 presented at adolescence with neurological symptoms tremor and amaurosis fugax but intact intellectual functioning [ 16 ], and case 52 presented only at the age of 57 years with progressive spastic paraparesis and dementia for four years [ 17 ]. Also, no cerebral MRI abnormalities were observed in case 52 who presented in adulthood with progressive spastic paraparesis, dementia for four years, and high plasma Phe concentrations [ 17 ], while cases 41 and 42 showed MRI involvement scores that were comparable with other late-diagnosed PKU patients [ 16 ].

Besides outcomes with respect to the central nervous system, for some included PKU patients, physical characteristics have been reported as well data not shown.

Many of these PKU patients showed the typical physical characteristics of untreated PKU: fair skin, blond hair, blue eyes, and sometimes also eczema. This study describes cases of PKU patients without ID despite late diagnosis with high plasma Phe concentrations, representing one of the old, but still unresolved, questions in PKU.

Most notable is the fact that we identified so many published cases with unexpected favorable outcome. The third remarkable finding was that, in some of the PKU patients, neurological symptoms only started at adult age, although this can still also be due to another disease rather than PKU.

Classical symptomatology of untreated or late-treated classical PKU consists of severe to global developmental delay, seizures, psychiatric disorders, and profound ID, with IQ declining to 40 or lower at one year of age [ 24 ].

It has been hypothesized that these patients may have some protecting mechanism, located at the blood-brain barrier or within the brain itself, that is involved in Phe transport or metabolism, or in the cerebral responses to high brain Phe concentrations [ 22 , 23 ] Fig.

At the level of the blood-brain barrier, LAT1 is considered to be the predominant transporter for Phe and other large neutral amino acids, and as such has been hypothesized to play a role in the inter-individual differences in brain vulnerability to high plasma Phe concentrations between PKU patients [ 28 ].

However, the transport of Phe and other large neutral amino acids across membranes of different cell types within the brain is less well understood. Interestingly, however, many of the here presented cases with normal intellectual functioning show some other cerebral e. Moreover, in contrast to the hypothesis of a possible variation in Phe transport from blood to brain in these patients, Phe concentrations in CSF of case 2 were correspondingly high with their plasma Phe concentrations [ 14 ].

Schematic picture outlining the hypotheses regarding the possible mechanism s underlying the inter-individual differences in brain vulnerability to high plasma Phe concentrations between PKU patients including: 1 a difference in the transport of Phe and other large neutral amino acids across the blood-brain barrier, 2 a difference in the transport of Phe and other large neutral amino acids across membranes of different cell types within the brain, and 3 a difference in the vulnerability of one or more of the intracerebral processes to high brain Phe concentrations.

These cases at least suggest that, even when ID is not seen, other neuropsychiatric symptoms may still exist, suggesting that the pathophysiology of brain dysfunction in PKU might relate to more than one mechanism. We, therefore, do not only need precise description of late-diagnosed PKU patients with unexpected favorable outcome despite high plasma Phe, but also need to further investigate these cases by modern techniques such as metabolomics and next generation sequencing to define the exact underlying mechanisms of PKU brain dysfunction.

The fact that more and more PKU patients are now diagnosed and treated from birth further necessitates that we really find these patients right now. Ztschr Physiol Chem. Article Google Scholar. Influence of phenylalanine intake on phenylketonuria. A simple phenylalanine method for detecting phenylketonuria in large populations of newborn infants. Current status of newborn screening worldwide: Semin Perinatol. Article PubMed Google Scholar. Neurocognitive evidence for revision of treatment targets and guidelines for phenylketonuria.

J Pediatr. J Inherit Metab Dis. Smith I, Knowles J. Behaviour in early treated phenylketonuria: a systematic review. Eur J Pediatr. Atypical phenylketonuria with borderline or normal intelligence. Am J Dis Child. For women with PKU, it's essential that they return to a strict diet if they're considering becoming pregnant, as high phenylalanine levels can harm an unborn child.

Women with PKU must take particular care during pregnancy, as high levels of phenylalanine can damage their unborn baby. Provided that phenylalanine levels are strictly controlled during pregnancy, problems can be avoided and there's no reason why a woman with PKU should not be able to have a normal, healthy baby. It's recommended that all women with PKU plan their pregnancies carefully. You should aim to follow a strict low-protein diet and monitor your blood twice a week before becoming pregnant.

It's best to try to conceive once phenylalanine levels are within the target range for pregnancy. During pregnancy, you'll be asked to provide blood samples 3 times a week and will be in frequent contact with a dietitian.

As soon as your baby is born, phenylalanine control can be relaxed and there's no reason why you cannot breastfeed your baby. Contact your PKU doctor and dietitian as soon as possible if you become pregnant when your phenylalanine levels are not adequately controlled.

If your phenylalanine levels can be brought under control within the first few weeks of your pregnancy, the risk of damage to your baby should be small.

But your pregnancy will need to be monitored very carefully. This helps scientists look for better ways to prevent and treat this condition. You can opt out of the register at any time.

Page last reviewed: 03 December Next review due: 03 December Phenylketonuria PKU is a rare but potentially serious inherited disorder. Other symptoms of untreated PKU include: behavioural difficulties such as frequent temper tantrums and episodes of self-harm fairer skin, hair and eyes than siblings who do not have the condition phenylalanine is involved in the body's production of melanin, the pigment responsible for skin and hair colour eczema repeatably being sick jerking movements in arms and legs tremors epilepsy musty smell to the breath, skin and urine Treating PKU Diet The main treatment for PKU is a low-protein diet that completely avoids high-protein foods such as meat, eggs and dairy products and controls the intake of many other foods, such as potatoes and cereals.

Aspartame People with PKU must also avoid food products that contain aspartame, as it's converted into phenylalanine in the body. Aspartame is a sweetener found in: sugar substitutes such as the artificial sweeteners often used in tea and coffee diet versions of fizzy drinks chewing gum squash and cordial some alcopops All food products that contain aspartame or a related product should be clearly labelled.

There are also medicines that contain aspartame, such as some children's cold and flu remedies. Regular blood tests A child with phenylketonuria will need regular blood tests to measure levels of phenylalanine in their blood and assess how well they're responding to treatment.

It's recommended that children who are: 6 months of age or younger should have their blood tested once a week between 6 months and 4 years of age should have their blood tested once every 2 weeks over 4 years of age should have their blood tested once a month Someone with PKU will usually need to have regular blood tests throughout their life.